diff --git a/.brazil.json b/.brazil.json
index 0908ffedb4..987379aec3 100644
--- a/.brazil.json
+++ b/.brazil.json
@@ -5,10 +5,12 @@
 
     "com.squareup.okhttp3:okhttp-coroutines:5.*": "OkHttp3Coroutines-5.x",
     "com.squareup.okhttp3:okhttp:5.*": "OkHttp3-5.x",
+    "com.squareup.okhttp3:okhttp-jvm:5.*": "OkHttp3-5.x",
     "com.squareup.okio:okio-jvm:3.*": "OkioJvm-3.x",
     "io.opentelemetry:opentelemetry-api:1.*": "Maven-io-opentelemetry_opentelemetry-api-1.x",
     "io.opentelemetry:opentelemetry-extension-kotlin:1.*": "Maven-io-opentelemetry_opentelemetry-extension-kotlin-1.x",
     "org.slf4j:slf4j-api:2.*": "Maven-org-slf4j_slf4j-api-2.x",
+    "aws.sdk.kotlin.crt:aws-crt-kotlin:0.10.*": "AwsCrtKotlin-0.10.x",
     "aws.sdk.kotlin.crt:aws-crt-kotlin:0.9.*": "AwsCrtKotlin-0.9.x",
     "aws.sdk.kotlin.crt:aws-crt-kotlin:0.8.*": "AwsCrtKotlin-0.8.x",
     "com.squareup.okhttp3:okhttp:4.*": "OkHttp3-4.x",
diff --git a/.github/workflows/merge-main.yml b/.github/workflows/merge-main.yml
index db1df3a142..ae4af7a055 100644
--- a/.github/workflows/merge-main.yml
+++ b/.github/workflows/merge-main.yml
@@ -12,4 +12,4 @@ jobs:
         uses: awslabs/aws-kotlin-repo-tools/.github/actions/merge-main@main
         with:
           ci-user-pat: ${{ secrets.CI_USER_PAT }}
-          exempt-branches: # Add any if required
\ No newline at end of file
+          exempt-branches: # Add any if required
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ad34f18d2e..eb355ef808 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,21 @@
 # Changelog
 
+## [1.5.1] - 07/17/2025
+
+## [1.5.0] - 07/17/2025
+
+### Features
+* Upgrade to Kotlin 2.2.0
+* [#1413](https://github.com/awslabs/aws-sdk-kotlin/issues/1413) ⚠️ **IMPORTANT**: Refactor endpoint discoverer classes into interfaces so custom implementations may be provided
+
+### Fixes
+* [#1311](https://github.com/smithy-lang/smithy-kotlin/issues/1311) Reimplement idle connection monitoring using `okhttp3.EventListener` instead of now-internal `okhttp3.ConnectionListener`
+* [#1608](https://github.com/awslabs/aws-sdk-kotlin/issues/1608) Switch to always serialize defaults in requests. Previously fields were not serialized in requests if they weren't `@required` and hadn't been changed from the default value.
+* [#1413](https://github.com/awslabs/aws-sdk-kotlin/issues/1413) Favor `endpointUrl` instead of endpoint discovery if both are provided
+
+### Miscellaneous
+* Add telemetry provider configuration to `DefaultAwsSigner`
+
 ## [1.4.23] - 07/15/2025
 
 ## [1.4.22] - 07/02/2025
diff --git a/bom/build.gradle.kts b/bom/build.gradle.kts
index 51b05616c1..8af09dbf58 100644
--- a/bom/build.gradle.kts
+++ b/bom/build.gradle.kts
@@ -7,8 +7,6 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinMultiplatformPluginWrapper
 import org.jetbrains.kotlin.gradle.plugin.KotlinTarget
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinMetadataTarget
-import org.jetbrains.kotlin.gradle.targets.js.KotlinJsTarget
-import java.util.*
 
 plugins {
     `maven-publish`
@@ -52,7 +50,6 @@ fun createBomConstraintsAndVersionCatalog() {
 
 fun Project.artifactId(target: KotlinTarget): String = when (target) {
     is KotlinMetadataTarget -> name
-    is KotlinJsTarget -> "$name-js"
     else -> "$name-${target.targetName.lowercase()}"
 }
 
diff --git a/build.gradle.kts b/build.gradle.kts
index bdec55641a..8b7a33571e 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -114,6 +114,7 @@ apiValidation {
             "nullability-tests",
             "paginator-tests",
             "waiter-tests",
+            "service-codegen-tests",
             "compile",
             "slf4j-1x-consumer",
             "slf4j-2x-consumer",
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
index f144c54f9f..9b25eaaa29 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupport.kt
@@ -40,7 +40,27 @@ class RegionSupport : KotlinIntegration {
             name = "region"
             symbol = KotlinTypes.String.toBuilder().nullable().build()
             documentation = """
-                The region to sign with and make requests to.
+                The AWS region to sign with and make requests to. When specified, this static region configuration
+                takes precedence over other region resolution methods. 
+                
+                The region resolution order is:
+                1. Static region (if specified)
+                2. Custom region provider (if configured)
+                3. Default region provider chain
+            """.trimIndent()
+        }
+
+        val RegionProviderProp: ConfigProperty = ConfigProperty {
+            name = "regionProvider"
+            symbol = RuntimeTypes.SmithyClient.Region.RegionProvider
+            documentation = """
+                An optional region provider that determines the AWS region for client operations. When specified, this provider
+                takes precedence over the default region provider chain, unless a static region is explicitly configured.
+              
+                The region resolution order is:
+                1. Static region (if specified)
+                2. Custom region provider (if configured)
+                3. Default region provider chain
             """.trimIndent()
         }
     }
@@ -57,7 +77,7 @@ class RegionSupport : KotlinIntegration {
         return supportsSigv4 || hasRegionBuiltin || isAwsSdk
     }
 
-    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> = listOf(RegionProp)
+    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> = listOf(RegionProp, RegionProviderProp)
 
     override fun customizeEndpointResolution(ctx: ProtocolGenerator.GenerationContext): EndpointCustomization =
         object : EndpointCustomization {
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
index 48d47a7c18..935eba31ab 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/AwsQuery.kt
@@ -7,17 +7,28 @@ package software.amazon.smithy.kotlin.codegen.aws.protocols
 
 import software.amazon.smithy.aws.traits.protocols.AwsQueryErrorTrait
 import software.amazon.smithy.aws.traits.protocols.AwsQueryTrait
+import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AbstractQueryFormUrlSerializerGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AwsHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RenderingContext
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
 import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
-import software.amazon.smithy.kotlin.codegen.model.*
-import software.amazon.smithy.kotlin.codegen.rendering.protocol.*
-import software.amazon.smithy.kotlin.codegen.rendering.serde.*
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+import software.amazon.smithy.kotlin.codegen.model.getTrait
+import software.amazon.smithy.kotlin.codegen.model.hasTrait
+import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.protocol.toRenderingContext
+import software.amazon.smithy.kotlin.codegen.rendering.serde.FormUrlSerdeDescriptorGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.StructuredDataParserGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.StructuredDataSerializerGenerator
+import software.amazon.smithy.kotlin.codegen.rendering.serde.XmlParserGenerator
 import software.amazon.smithy.model.shapes.*
-import software.amazon.smithy.model.traits.*
+import software.amazon.smithy.model.traits.XmlFlattenedTrait
+import software.amazon.smithy.model.traits.XmlNameTrait
 
 /**
  * Handles generating the aws.protocols#awsQuery protocol for services.
@@ -45,7 +56,7 @@ class AwsQuery : QueryHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponse)
     }
 }
 
@@ -76,6 +87,14 @@ private class AwsQuerySerializerGenerator(
         members: List<MemberShape>,
         writer: KotlinWriter,
     ): FormUrlSerdeDescriptorGenerator = AwsQuerySerdeFormUrlDescriptorGenerator(ctx.toRenderingContext(protocolGenerator, shape, writer), members)
+
+    override fun errorSerializer(
+        ctx: ProtocolGenerator.GenerationContext,
+        errorShape: StructureShape,
+        members: List<MemberShape>,
+    ): Symbol {
+        TODO("Used for service-codegen. Not yet implemented")
+    }
 }
 
 private class AwsQueryXmlParserGenerator(
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
index 10be8bfc6e..38e74d010d 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/Ec2Query.kt
@@ -10,7 +10,10 @@ import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.AbstractQueryFormUrlSerializerGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.core.QueryHttpBindingProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.aws.protocols.formurl.QuerySerdeFormUrlDescriptorGenerator
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RenderingContext
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.getTrait
 import software.amazon.smithy.kotlin.codegen.model.isNullable
@@ -39,7 +42,7 @@ class Ec2Query : QueryHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseEc2QueryErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseEc2QueryErrorResponse)
     }
 }
 
@@ -95,6 +98,14 @@ private class Ec2QuerySerializerGenerator(
         members: List<MemberShape>,
         writer: KotlinWriter,
     ): FormUrlSerdeDescriptorGenerator = Ec2QuerySerdeFormUrlDescriptorGenerator(ctx.toRenderingContext(protocolGenerator, shape, writer), members)
+
+    override fun errorSerializer(
+        ctx: ProtocolGenerator.GenerationContext,
+        errorShape: StructureShape,
+        members: List<MemberShape>,
+    ): Symbol {
+        TODO("Used for service-codegen. Not yet implemented")
+    }
 }
 
 private class Ec2QueryParserGenerator(
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestJson1.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestJson1.kt
index dcf2f0a814..db6591738f 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestJson1.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestJson1.kt
@@ -40,9 +40,11 @@ class RestJson1 : JsonHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         super.renderSerializeHttpBody(ctx, op, writer)
+        if (ctx.settings.build.generateServiceProject) return
 
         val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
-        if (!resolver.hasHttpBody(op)) return
+
+        if (!resolver.hasHttpRequestBody(op)) return
 
         // restjson1 has some different semantics and expectations around empty structures bound via @httpPayload trait
         //   * empty structures get serialized to `{}`
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
index 7c1f45b92c..c7c834c317 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RestXml.kt
@@ -63,7 +63,7 @@ open class RestXml : AwsHttpBindingProtocolGenerator() {
         writer: KotlinWriter,
     ) {
         writer.write("""checkNotNull(payload){ "unable to parse error from empty response" }""")
-        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponseNoSuspend)
+        writer.write("#T(payload)", RuntimeTypes.AwsXmlProtocols.parseRestXmlErrorResponse)
     }
 }
 
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RpcV2Cbor.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RpcV2Cbor.kt
index 117574da40..ff09bc0d5b 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RpcV2Cbor.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/RpcV2Cbor.kt
@@ -103,19 +103,30 @@ class RpcV2Cbor : AwsHttpBindingProtocolGenerator() {
         if (!op.hasHttpBody(ctx)) return
 
         // payload member(s)
-        val requestBindings = resolver.requestBindings(op)
-        val httpPayload = requestBindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
+        val bindings = if (ctx.settings.build.generateServiceProject) {
+            resolver.responseBindings(op)
+        } else {
+            resolver.requestBindings(op)
+        }
+        val httpPayload = bindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
+
         if (httpPayload != null) {
             renderExplicitHttpPayloadSerializer(ctx, httpPayload, writer)
         } else {
-            val documentMembers = requestBindings.filterDocumentBoundMembers()
+            val documentMembers = bindings.filterDocumentBoundMembers()
             // Unbound document members that should be serialized into the document format for the protocol.
             // delegate to the generate operation body serializer function
             val sdg = structuredDataSerializer(ctx)
             val opBodySerializerFn = sdg.operationSerializer(ctx, op, documentMembers)
-            writer.write("builder.body = #T(context, input)", opBodySerializerFn)
+            if (ctx.settings.build.generateServiceProject) {
+                writer.write("response = #T(context, input)", opBodySerializerFn)
+            } else {
+                writer.write("builder.body = #T(context, input)", opBodySerializerFn)
+            }
+        }
+        if (!ctx.settings.build.generateServiceProject) {
+            renderContentTypeHeader(ctx, op, writer, resolver)
         }
-        renderContentTypeHeader(ctx, op, writer, resolver)
     }
 
     /**
diff --git a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/StaticHttpBindingResolver.kt b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/StaticHttpBindingResolver.kt
index f549d0ed4c..06155287d6 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/StaticHttpBindingResolver.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/StaticHttpBindingResolver.kt
@@ -56,10 +56,16 @@ open class StaticHttpBindingResolver(
     /**
      * By default returns all inputs as [HttpBinding.Location.DOCUMENT]
      */
-    override fun requestBindings(operationShape: OperationShape): List<HttpBindingDescriptor> {
-        if (!operationShape.input.isPresent) return emptyList()
-        val input = model.expectShape(operationShape.input.get())
-        return input.members().map { member -> HttpBindingDescriptor(member, HttpBinding.Location.DOCUMENT) }.toList()
+    override fun requestBindings(shape: Shape): List<HttpBindingDescriptor> {
+        when (shape) {
+            is OperationShape -> {
+                if (!shape.input.isPresent) return emptyList()
+                val input = model.expectShape(shape.input.get())
+                return input.members().map { member -> HttpBindingDescriptor(member, HttpBinding.Location.DOCUMENT) }.toList()
+            }
+            is StructureShape -> return shape.members().map { member -> member.toHttpBindingDescriptor() }.toList()
+            else -> error("unimplemented shape type for http response bindings: $shape")
+        }
     }
 
     /**
diff --git a/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt
new file mode 100644
index 0000000000..2df3e519f0
--- /dev/null
+++ b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/customization/RegionSupportTest.kt
@@ -0,0 +1,73 @@
+package software.amazon.smithy.kotlin.codegen.aws.customization
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.model.expectShape
+import software.amazon.smithy.kotlin.codegen.rendering.ServiceClientConfigGenerator
+import software.amazon.smithy.kotlin.codegen.test.*
+import software.amazon.smithy.model.shapes.ServiceShape
+
+class RegionSupportTest {
+    @Test
+    fun testRegionSupportProperties() {
+        val model = """
+            namespace com.test
+
+            use aws.protocols#awsJson1_1
+            use aws.api#service
+            use aws.auth#sigv4
+
+            @service(sdkId: "service with overrides", endpointPrefix: "service-with-overrides")
+            @sigv4(name: "example")
+            @awsJson1_1
+            service Example {
+                version: "1.0.0",
+                operations: [GetFoo]
+            }
+
+            operation GetFoo {}
+        """.toSmithyModel()
+
+        val serviceShape = model.expectShape<ServiceShape>("com.test#Example")
+
+        val testCtx = model.newTestContext(serviceName = "Example")
+        val writer = KotlinWriter("com.test")
+
+        val renderingCtx = testCtx.toRenderingContext(writer, serviceShape)
+            .copy(integrations = listOf(RegionSupport()))
+
+        ServiceClientConfigGenerator(serviceShape, detectDefaultProps = false).render(renderingCtx, renderingCtx.writer)
+        val contents = writer.toString()
+
+        val expectedProps = """
+            public val region: String? = builder.region
+            public val regionProvider: RegionProvider? = builder.regionProvider
+        """.formatForTest()
+        contents.shouldContainOnlyOnceWithDiff(expectedProps)
+
+        val expectedImpl = """
+            /**
+             * The AWS region to sign with and make requests to. When specified, this static region configuration
+             * takes precedence over other region resolution methods.
+             *
+             * The region resolution order is:
+             * 1. Static region (if specified)
+             * 2. Custom region provider (if configured)
+             * 3. Default region provider chain
+             */
+            public var region: String? = null
+    
+            /**
+             * An optional region provider that determines the AWS region for client operations. When specified, this provider
+             * takes precedence over the default region provider chain, unless a static region is explicitly configured.
+             *
+             * The region resolution order is:
+             * 1. Static region (if specified)
+             * 2. Custom region provider (if configured)
+             * 3. Default region provider chain
+             */
+            public var regionProvider: RegionProvider? = null
+        """.formatForTest(indent = "        ")
+        contents.shouldContainOnlyOnceWithDiff(expectedImpl)
+    }
+}
diff --git a/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/AwsHttpBindingProtocolGeneratorTest.kt b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/AwsHttpBindingProtocolGeneratorTest.kt
index 19a1963844..3fbf2cfadc 100644
--- a/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/AwsHttpBindingProtocolGeneratorTest.kt
+++ b/codegen/smithy-aws-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/aws/protocols/core/AwsHttpBindingProtocolGeneratorTest.kt
@@ -123,6 +123,14 @@ class AwsHttpBindingProtocolGeneratorTest {
                 ): Symbol {
                     error("Unneeded for test")
                 }
+
+                override fun errorSerializer(
+                    ctx: ProtocolGenerator.GenerationContext,
+                    errorShape: StructureShape,
+                    members: List<MemberShape>,
+                ): Symbol {
+                    error("Unneeded for test")
+                }
             }
 
         override val protocol: ShapeId
diff --git a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/CodegenTestUtils.kt b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/CodegenTestUtils.kt
index 164e7cb2e6..c8fae63ca8 100644
--- a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/CodegenTestUtils.kt
+++ b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/CodegenTestUtils.kt
@@ -214,6 +214,14 @@ class MockHttpProtocolGenerator(model: Model) : HttpBindingProtocolGenerator() {
                 val symbol = ctx.symbolProvider.toSymbol(shape)
                 name = "serialize" + StringUtils.capitalize(symbol.name) + "Payload"
             }
+
+            override fun errorSerializer(
+                ctx: ProtocolGenerator.GenerationContext,
+                errorShape: StructureShape,
+                members: List<MemberShape>,
+            ): Symbol {
+                error("Unneeded for test")
+            }
         }
 
     override fun operationErrorHandler(ctx: ProtocolGenerator.GenerationContext, op: OperationShape): Symbol = buildSymbol {
diff --git a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
index e857f91fee..4c421f7fa7 100644
--- a/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
+++ b/codegen/smithy-kotlin-codegen-testutils/src/main/kotlin/software/amazon/smithy/kotlin/codegen/test/ModelTestUtils.kt
@@ -8,6 +8,7 @@ import software.amazon.smithy.build.MockManifest
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.*
 import software.amazon.smithy.kotlin.codegen.core.CodegenContext
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
 import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.model.OperationNormalizer
@@ -122,9 +123,11 @@ fun Model.newTestContext(
     val manifest = MockManifest()
     val provider: SymbolProvider = KotlinCodegenPlugin.createSymbolProvider(model = this, rootNamespace = packageName, serviceName = serviceName, settings = settings)
     val service = this.getShape(ShapeId.from("$packageName#$serviceName")).get().asServiceShape().get()
-    val delegator = KotlinDelegator(settings, this, manifest, provider, integrations)
 
-    val ctx = ProtocolGenerator.GenerationContext(
+    val codegenCtx = GenerationContext(this, provider, settings, generator, integrations)
+    val delegator = KotlinDelegator(codegenCtx, manifest, integrations)
+
+    val generationCtx = ProtocolGenerator.GenerationContext(
         settings,
         this,
         service,
@@ -133,7 +136,8 @@ fun Model.newTestContext(
         generator.protocol,
         delegator,
     )
-    return TestContext(ctx, manifest, generator)
+
+    return TestContext(generationCtx, manifest, generator)
 }
 
 fun TestContext.toCodegenContext() = object : CodegenContext {
@@ -173,7 +177,7 @@ fun Model.defaultSettings(
     sdkId: String = TestModelDefault.SDK_ID,
     generateDefaultBuildFiles: Boolean = false,
     nullabilityCheckMode: CheckMode = CheckMode.CLIENT_CAREFUL,
-    defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT,
+    defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.DEFAULT,
 ): KotlinSettings {
     val serviceId = if (serviceName == null) {
         this.inferService()
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
index 4adf42b91f..1447363d4a 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/CodegenVisitor.kt
@@ -20,6 +20,7 @@ import software.amazon.smithy.kotlin.codegen.model.hasTrait
 import software.amazon.smithy.kotlin.codegen.rendering.*
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ApplicationProtocol
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
+import software.amazon.smithy.kotlin.codegen.service.AbstractStubGenerator
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.knowledge.ServiceIndex
 import software.amazon.smithy.model.neighbor.Walker
@@ -87,12 +88,12 @@ class CodegenVisitor(context: PluginContext) : ShapeVisitor.Default<Unit>() {
             integration.decorateSymbolProvider(settings, model, provider)
         }
 
-        writers = KotlinDelegator(settings, model, fileManifest, symbolProvider, integrations)
-
         protocolGenerator = resolveProtocolGenerator(integrations, model, service, settings)
-        applicationProtocol = protocolGenerator?.applicationProtocol ?: ApplicationProtocol.createDefaultHttpApplicationProtocol()
-
         baseGenerationContext = GenerationContext(model, symbolProvider, settings, protocolGenerator, integrations)
+
+        writers = KotlinDelegator(baseGenerationContext, fileManifest, integrations)
+
+        applicationProtocol = protocolGenerator?.applicationProtocol ?: ApplicationProtocol.createDefaultHttpApplicationProtocol()
     }
 
     private fun resolveProtocolGenerator(
@@ -114,7 +115,12 @@ class CodegenVisitor(context: PluginContext) : ShapeVisitor.Default<Unit>() {
     }
 
     fun execute() {
-        logger.info("Generating Kotlin client for service ${settings.service}")
+        val generateServiceProject = settings.build.generateServiceProject
+        if (generateServiceProject) {
+            logger.info("Generating Kotlin service ${settings.service}")
+        } else {
+            logger.info("Generating Kotlin client for service ${settings.service}")
+        }
 
         logger.info("Walking shapes from ${settings.service} to find shapes to generate")
         val modelWithoutTraits = ModelTransformer.create().getModelWithoutTraitShapes(model)
@@ -138,11 +144,18 @@ class CodegenVisitor(context: PluginContext) : ShapeVisitor.Default<Unit>() {
             logger.info("[${service.id}] Generating service client for protocol $protocol")
             generateProtocolClient(ctx)
 
-            logger.info("[${service.id}] Generating endpoint provider for protocol $protocol")
-            generateEndpointsSources(ctx)
+            if (!generateServiceProject) {
+                logger.info("[${service.id}] Generating endpoint provider for protocol $protocol")
+                generateEndpointsSources(ctx)
+
+                logger.info("[${service.id}] Generating auth scheme provider for protocol $protocol")
+                generateAuthSchemeProvider(ctx)
+            }
+        }
 
-            logger.info("[${service.id}] Generating auth scheme provider for protocol $protocol")
-            generateAuthSchemeProvider(ctx)
+        if (generateServiceProject) {
+            val serviceStubGenerator: AbstractStubGenerator = settings.serviceStub.framework.getServiceFrameworkGenerator(baseGenerationContext, writers, fileManifest)
+            serviceStubGenerator.render()
         }
 
         writers.finalize()
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
index 3ee6e0633b..01025bf77a 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettings.kt
@@ -5,14 +5,10 @@
 
 package software.amazon.smithy.kotlin.codegen
 
-import software.amazon.smithy.aws.traits.protocols.AwsJson1_0Trait
-import software.amazon.smithy.aws.traits.protocols.AwsJson1_1Trait
-import software.amazon.smithy.aws.traits.protocols.AwsQueryTrait
-import software.amazon.smithy.aws.traits.protocols.Ec2QueryTrait
-import software.amazon.smithy.aws.traits.protocols.RestJson1Trait
-import software.amazon.smithy.aws.traits.protocols.RestXmlTrait
+import software.amazon.smithy.aws.traits.protocols.*
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.kotlin.codegen.lang.isValidPackageName
+import software.amazon.smithy.kotlin.codegen.service.ServiceFramework
 import software.amazon.smithy.kotlin.codegen.utils.getOrNull
 import software.amazon.smithy.kotlin.codegen.utils.toCamelCase
 import software.amazon.smithy.model.Model
@@ -24,10 +20,10 @@ import software.amazon.smithy.model.shapes.ServiceShape
 import software.amazon.smithy.model.shapes.Shape
 import software.amazon.smithy.model.shapes.ShapeId
 import software.amazon.smithy.protocol.traits.Rpcv2CborTrait
-import java.util.Optional
+import java.util.*
 import java.util.logging.Logger
+import java.util.stream.Collectors
 import kotlin.IllegalArgumentException
-import kotlin.streams.toList
 
 // shapeId of service from which to generate an SDK
 private const val SERVICE = "service"
@@ -37,6 +33,7 @@ private const val PACKAGE_VERSION = "version"
 private const val PACKAGE_DESCRIPTION = "description"
 private const val BUILD_SETTINGS = "build"
 private const val API_SETTINGS = "api"
+private const val SERVICE_STUB_SETTINGS = "serviceStub"
 
 // Optional specification of sdkId for models that provide them, otherwise Service's shape id name is used
 private const val SDK_ID = "sdkId"
@@ -61,6 +58,7 @@ data class KotlinSettings(
     val sdkId: String,
     val build: BuildSettings = BuildSettings.Default,
     val api: ApiSettings = ApiSettings.Default,
+    val serviceStub: ServiceStubSettings = ServiceStubSettings.Default,
     val debug: Boolean = false,
 ) {
 
@@ -103,7 +101,7 @@ data class KotlinSettings(
          * @return Returns the extracted settings
          */
         fun from(model: Model, config: ObjectNode): KotlinSettings {
-            config.warnIfAdditionalProperties(listOf(SERVICE, PACKAGE_SETTINGS, BUILD_SETTINGS, SDK_ID, API_SETTINGS))
+            config.warnIfAdditionalProperties(listOf(SERVICE, PACKAGE_SETTINGS, BUILD_SETTINGS, SDK_ID, API_SETTINGS, SERVICE_STUB_SETTINGS))
 
             val serviceId = config.getStringMember(SERVICE)
                 .map(StringNode::expectShapeId)
@@ -123,6 +121,7 @@ data class KotlinSettings(
             val sdkId = config.getStringMemberOrDefault(SDK_ID, serviceId.name)
             val build = config.getObjectMember(BUILD_SETTINGS)
             val api = config.getObjectMember(API_SETTINGS)
+            val serviceStub = config.getObjectMember(SERVICE_STUB_SETTINGS)
             val debug = config.getBooleanMemberOrDefault("debug", false)
             return KotlinSettings(
                 serviceId,
@@ -130,6 +129,7 @@ data class KotlinSettings(
                 sdkId,
                 BuildSettings.fromNode(build),
                 ApiSettings.fromNode(api),
+                ServiceStubSettings.fromNode(serviceStub),
                 debug,
             )
         }
@@ -164,7 +164,7 @@ fun Model.inferService(): ShapeId {
     val services = shapes(ServiceShape::class.java)
         .map(Shape::getId)
         .sorted()
-        .toList()
+        .collect(Collectors.toList())
 
     return when {
         services.isEmpty() -> {
@@ -190,23 +190,27 @@ fun Model.inferService(): ShapeId {
  * @param optInAnnotations Kotlin opt-in annotations. See:
  * https://kotlinlang.org/docs/reference/opt-in-requirements.html
  * @param generateMultiplatformProject Flag indicating to generate a Kotlin multiplatform or JVM project
+ * @param generateServiceProject Flag indicating to generate a Kotlin service project
  */
 data class BuildSettings(
     val generateFullProject: Boolean = false,
     val generateDefaultBuildFiles: Boolean = true,
     val optInAnnotations: List<String>? = null,
     val generateMultiplatformProject: Boolean = false,
+    val generateServiceProject: Boolean = false,
 ) {
     companion object {
         const val ROOT_PROJECT = "rootProject"
         const val GENERATE_DEFAULT_BUILD_FILES = "generateDefaultBuildFiles"
         const val ANNOTATIONS = "optInAnnotations"
         const val GENERATE_MULTIPLATFORM_MODULE = "multiplatform"
+        const val GENERATE_SERVICE_PROJECT = "generateServiceProject"
 
         fun fromNode(node: Optional<ObjectNode>): BuildSettings = node.map {
             val generateFullProject = node.get().getBooleanMemberOrDefault(ROOT_PROJECT, false)
             val generateBuildFiles = node.get().getBooleanMemberOrDefault(GENERATE_DEFAULT_BUILD_FILES, true)
             val generateMultiplatformProject = node.get().getBooleanMemberOrDefault(GENERATE_MULTIPLATFORM_MODULE, false)
+            val generateServiceProject = node.get().getBooleanMemberOrDefault(GENERATE_SERVICE_PROJECT, false)
             val annotations = node.get().getArrayMember(ANNOTATIONS).map {
                 it.elements.mapNotNull { node ->
                     node.asStringNode().map { stringNode ->
@@ -214,7 +218,7 @@ data class BuildSettings(
                     }.orNull()
                 }
             }.orNull()
-            BuildSettings(generateFullProject, generateBuildFiles, annotations, generateMultiplatformProject)
+            BuildSettings(generateFullProject, generateBuildFiles, annotations, generateMultiplatformProject, generateServiceProject)
         }.orElse(Default)
 
         /**
@@ -273,10 +277,15 @@ enum class DefaultValueSerializationMode(val value: String) {
 
     override fun toString(): String = value
     companion object {
+        /**
+         * The default value serialization mode, which is [ALWAYS]
+         */
+        val DEFAULT = ALWAYS
+
         fun fromValue(value: String): DefaultValueSerializationMode =
-            values().find {
-                it.value == value
-            } ?: throw IllegalArgumentException("$value is not a valid DefaultValueSerializationMode, expected one of ${values().map { it.value }}")
+            requireNotNull(entries.find { it.value.equals(value, ignoreCase = true) }) {
+                "$value is not a valid DefaultValueSerializationMode, expected one of ${values().map { it.value }}"
+            }
     }
 }
 
@@ -291,7 +300,7 @@ enum class DefaultValueSerializationMode(val value: String) {
 data class ApiSettings(
     val visibility: Visibility = Visibility.PUBLIC,
     val nullabilityCheckMode: CheckMode = CheckMode.CLIENT_CAREFUL,
-    val defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT,
+    val defaultValueSerializationMode: DefaultValueSerializationMode = DefaultValueSerializationMode.DEFAULT,
     val enableEndpointAuthProvider: Boolean = false,
     val protocolResolutionPriority: Set<ShapeId> = DEFAULT_PROTOCOL_RESOLUTION_PRIORITY,
 ) {
@@ -315,7 +324,7 @@ data class ApiSettings(
                 node.get()
                     .getStringMemberOrDefault(
                         DEFAULT_VALUE_SERIALIZATION_MODE,
-                        DefaultValueSerializationMode.WHEN_DIFFERENT.value,
+                        DefaultValueSerializationMode.DEFAULT.value,
                     ),
             )
             val enableEndpointAuthProvider = node.get().getBooleanMemberOrDefault(ENABLE_ENDPOINT_AUTH_PROVIDER, false)
@@ -335,3 +344,29 @@ data class ApiSettings(
         val Default: ApiSettings = ApiSettings()
     }
 }
+
+/**
+ * Contains configurations settings for a Kotlin service project
+ * @param framework Enum representing the server framework of the service.
+ */
+data class ServiceStubSettings(
+    val framework: ServiceFramework = ServiceFramework.KTOR,
+) {
+    companion object {
+        const val SERVER_FRAMEWORK = "serverFramework"
+
+        fun fromNode(node: Optional<ObjectNode>): ServiceStubSettings = node.map {
+            val serverFramework = node.get()
+                .getStringMember(SERVER_FRAMEWORK)
+                .map { ServiceFramework.fromValue(it.value) }
+                .getOrNull() ?: ServiceFramework.KTOR
+
+            ServiceStubSettings(serverFramework)
+        }.orElse(Default)
+
+        /**
+         * Default service stub settings
+         */
+        val Default: ServiceStubSettings = ServiceStubSettings()
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
index 2b943da042..186dcec017 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/AbstractCodeWriterExt.kt
@@ -150,6 +150,15 @@ inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.getConte
  */
 inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.getContextValue(key: SectionKey<V>): V = getContextValue(key.name)
 
+/**
+ * Convenience function to set a typed value in the context
+ * @param key
+ */
+inline fun <W : AbstractCodeWriter<W>, reified V> AbstractCodeWriter<W>.putContextValue(
+    key: SectionKey<V>,
+    value: V,
+): W = putContext(key.name, value)
+
 /**
  * Convenience function to set context only if there is no value already associated with the given [key]
  */
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
index 06d8b7497d..a3f714d741 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/CodegenContext.kt
@@ -8,6 +8,7 @@ package software.amazon.smithy.kotlin.codegen.core
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
+import software.amazon.smithy.kotlin.codegen.integration.SectionKey
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
 import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.Shape
@@ -16,6 +17,10 @@ import software.amazon.smithy.model.shapes.Shape
  * Common codegen properties required across different codegen contexts
  */
 interface CodegenContext {
+    companion object {
+        val Key = SectionKey<CodegenContext>("CodegenContext")
+    }
+
     val model: Model
     val symbolProvider: SymbolProvider
     val settings: KotlinSettings
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
index 9ae10da763..ea0b6459f1 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegator.kt
@@ -6,11 +6,9 @@ package software.amazon.smithy.kotlin.codegen.core
 
 import software.amazon.smithy.build.FileManifest
 import software.amazon.smithy.codegen.core.*
-import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.model.SymbolProperty
 import software.amazon.smithy.kotlin.codegen.utils.namespaceToPath
-import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.Shape
 import java.nio.file.Paths
 
@@ -21,13 +19,10 @@ const val DEFAULT_TEST_SOURCE_SET_ROOT = "./src/test/kotlin/"
  * Manages writers for Kotlin files.
  */
 class KotlinDelegator(
-    private val settings: KotlinSettings,
-    private val model: Model,
+    private val ctx: CodegenContext,
     val fileManifest: FileManifest,
-    private val symbolProvider: SymbolProvider,
     private val integrations: List<KotlinIntegration> = listOf(),
 ) {
-
     private val writers: MutableMap<String, KotlinWriter> = mutableMapOf()
 
     // Tracks dependencies for source not provided by codegen that may reside in the service source tree.
@@ -91,7 +86,7 @@ class KotlinDelegator(
         shape: Shape,
         block: (KotlinWriter) -> Unit,
     ) {
-        val symbol = symbolProvider.toSymbol(shape)
+        val symbol = ctx.symbolProvider.toSymbol(shape)
         useSymbolWriter(symbol, block)
     }
 
@@ -151,7 +146,9 @@ class KotlinDelegator(
         val needsNewline = writers.containsKey(formattedFilename)
         val writer = writers.getOrPut(formattedFilename) {
             val kotlinWriter = KotlinWriter(namespace)
-            if (settings.debug) kotlinWriter.enableStackTraceComments(true)
+            kotlinWriter.putContextValue(CodegenContext.Key, ctx)
+
+            if (ctx.settings.debug) kotlinWriter.enableStackTraceComments(true)
 
             // Register all integrations [SectionWriterBindings] on the writer.
             integrations.forEach { integration ->
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
index b575efae60..3fe6d45c02 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDependency.kt
@@ -37,7 +37,11 @@ private fun getDefaultRuntimeVersion(): String {
 // publishing info
 const val RUNTIME_GROUP: String = "aws.smithy.kotlin"
 val RUNTIME_VERSION: String = System.getProperty("smithy.kotlin.codegen.clientRuntimeVersion", getDefaultRuntimeVersion())
-val KOTLIN_COMPILER_VERSION: String = System.getProperty("smithy.kotlin.codegen.kotlinCompilerVersion", "2.1.0")
+val KOTLIN_COMPILER_VERSION: String = System.getProperty("smithy.kotlin.codegen.kotlinCompilerVersion", "2.2.0")
+val KTOR_VERSION: String = System.getProperty("smithy.kotlin.codegen.ktorVersion", "3.2.2")
+val SERIALIZATION_PLUGIN: String = System.getProperty("smithy.kotlin.codegen.SerializationPlugin", "2.0.20")
+val KOTLINX_VERSION: String = System.getProperty("smithy.kotlin.codegen.ktorKotlinxVersion", "1.9.0")
+val KTOR_LOGGING_BACKEND_VERSION: String = System.getProperty("smithy.kotlin.codegen.ktorLoggingBackendVersion", "1.4.14")
 
 enum class SourceSet {
     CommonMain,
@@ -134,6 +138,25 @@ data class KotlinDependency(
         // External third-party dependencies
         val KOTLIN_STDLIB = KotlinDependency(GradleConfiguration.Implementation, "kotlin", "org.jetbrains.kotlin", "kotlin-stdlib", KOTLIN_COMPILER_VERSION)
         val KOTLIN_TEST = KotlinDependency(GradleConfiguration.TestImplementation, "kotlin.test", "org.jetbrains.kotlin", "kotlin-test", KOTLIN_COMPILER_VERSION)
+        val KOTLIN_TEST_IMPL = KOTLIN_TEST.copy(config = GradleConfiguration.Implementation)
+
+        // Ktor server dependencies
+        // FIXME: version numbers should not be hardcoded, they should be setting dynamically based on the Gradle library versions
+        val KTOR_SERVER_CORE = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server", "io.ktor", "ktor-server-core", KTOR_VERSION)
+        val KTOR_SERVER_UTILS = KotlinDependency(GradleConfiguration.Implementation, "io.ktor", "io.ktor", "ktor-server-core", KTOR_VERSION)
+        val KTOR_SERVER_NETTY = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.netty", "io.ktor", "ktor-server-netty", KTOR_VERSION)
+        val KTOR_SERVER_CIO = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.cio", "io.ktor", "ktor-server-cio", KTOR_VERSION)
+        val KTOR_SERVER_JETTY_JAKARTA = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.jetty.jakarta", "io.ktor", "ktor-server-jetty-jakarta", KTOR_VERSION)
+        val KTOR_SERVER_HTTP = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.http", "io.ktor", "ktor-http-jvm", KTOR_VERSION)
+        val KTOR_SERVER_LOGGING = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.plugins.calllogging", "io.ktor", "ktor-server-call-logging", KTOR_VERSION)
+        val KTOR_SERVER_BODY_LIMIT = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.plugins", "io.ktor", "ktor-server-body-limit", KTOR_VERSION)
+        val KTOR_LOGGING_SLF4J = KotlinDependency(GradleConfiguration.Implementation, "org.slf4j", "ch.qos.logback", "logback-classic", KTOR_LOGGING_BACKEND_VERSION)
+        val KTOR_LOGGING_LOGBACK = KotlinDependency(GradleConfiguration.Implementation, "ch.qos.logback", "ch.qos.logback", "logback-classic", KTOR_LOGGING_BACKEND_VERSION)
+        val KTOR_SERVER_STATUS_PAGE = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.plugins.statuspages", "io.ktor", "ktor-server-status-pages-jvm", KTOR_VERSION)
+        val KOTLINX_CBOR_SERDE = KotlinDependency(GradleConfiguration.Implementation, "kotlinx.serialization", "org.jetbrains.kotlinx", "kotlinx-serialization-cbor", KOTLINX_VERSION)
+        val KOTLINX_JSON_SERDE = KotlinDependency(GradleConfiguration.Implementation, "kotlinx.serialization.json", "org.jetbrains.kotlinx", "kotlinx-serialization-json", KOTLINX_VERSION)
+        val KTOR_SERVER_AUTH = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.auth", "io.ktor", "ktor-server-auth", KTOR_VERSION)
+        val KTOR_SERVER_DOUBLE_RECEIVE = KotlinDependency(GradleConfiguration.Implementation, "io.ktor.server.plugins.doublereceive", "io.ktor", "ktor-server-double-receive-jvm", KTOR_VERSION)
     }
 
     override fun getDependencies(): List<SymbolDependency> {
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinSymbolProvider.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinSymbolProvider.kt
index 8313f38c9c..e8bd0d1c6e 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinSymbolProvider.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinSymbolProvider.kt
@@ -6,6 +6,7 @@ package software.amazon.smithy.kotlin.codegen.core
 
 import software.amazon.smithy.codegen.core.*
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.lang.kotlinReservedWords
 import software.amazon.smithy.kotlin.codegen.model.*
 import software.amazon.smithy.kotlin.codegen.utils.dq
@@ -332,6 +333,10 @@ class KotlinSymbolProvider(private val model: Model, private val settings: Kotli
     }
 
     override fun serviceShape(shape: ServiceShape): Symbol {
+        if (settings.build.generateServiceProject) {
+            // Intentionally not generating a *client symbol* for the service
+            return KotlinTypes.Nothing
+        }
         val serviceName = clientName(settings.sdkId)
         return createSymbolBuilder(shape, "${serviceName}Client")
             .namespace(rootNamespace, ".")
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
index 1cbf3b407b..1c8c4f4e8b 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/core/RuntimeTypes.kt
@@ -45,11 +45,11 @@ object RuntimeTypes {
     object HttpClient : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT) {
         val SdkHttpClient = symbol("SdkHttpClient")
 
-        object Middleware : RuntimeTypePackage(KotlinDependency.HTTP, "middleware") {
+        object Middleware : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "middleware") {
             val MutateHeadersMiddleware = symbol("MutateHeaders")
         }
 
-        object Operation : RuntimeTypePackage(KotlinDependency.HTTP, "operation") {
+        object Operation : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "operation") {
             val AuthSchemeResolver = symbol("AuthSchemeResolver")
             val context = symbol("context")
             val EndpointResolver = symbol("EndpointResolver")
@@ -68,18 +68,19 @@ object RuntimeTypes {
             val setResolvedEndpoint = symbol("setResolvedEndpoint")
         }
 
-        object Config : RuntimeTypePackage(KotlinDependency.HTTP, "config") {
+        object Config : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "config") {
             val HttpClientConfig = symbol("HttpClientConfig")
             val HttpEngineConfig = symbol("HttpEngineConfig")
         }
 
-        object Engine : RuntimeTypePackage(KotlinDependency.HTTP, "engine") {
+        object Engine : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "engine") {
             val HttpClientEngine = symbol("HttpClientEngine")
             val manage = symbol("manage", "engine.internal", isExtension = true)
         }
 
-        object Interceptors : RuntimeTypePackage(KotlinDependency.HTTP, "interceptors") {
+        object Interceptors : RuntimeTypePackage(KotlinDependency.HTTP_CLIENT, "interceptors") {
             val ContinueInterceptor = symbol("ContinueInterceptor")
+            val DiscoveredEndpointErrorInterceptor = symbol("DiscoveredEndpointErrorInterceptor")
             val HttpInterceptor = symbol("HttpInterceptor")
             val HttpChecksumRequiredInterceptor = symbol("HttpChecksumRequiredInterceptor")
             val FlexibleChecksumsRequestInterceptor = symbol("FlexibleChecksumsRequestInterceptor")
@@ -97,7 +98,6 @@ object RuntimeTypes {
     }
 
     object Core : RuntimeTypePackage(KotlinDependency.CORE) {
-        val Clock = symbol("Clock", "time")
         val ExecutionContext = symbol("ExecutionContext", "operation")
         val ErrorMetadata = symbol("ErrorMetadata")
         val ServiceErrorMetadata = symbol("ServiceErrorMetadata")
@@ -126,11 +126,12 @@ object RuntimeTypes {
             val attributesOf = symbol("attributesOf")
             val AttributeKey = symbol("AttributeKey")
             val createOrAppend = symbol("createOrAppend")
+            val ExpiringKeyedCache = symbol("ExpiringKeyedCache")
             val get = symbol("get")
             val mutableMultiMapOf = symbol("mutableMultiMapOf")
+            val PeriodicSweepCache = symbol("PeriodicSweepCache")
             val putIfAbsent = symbol("putIfAbsent")
             val putIfAbsentNotNull = symbol("putIfAbsentNotNull")
-            val ReadThroughCache = symbol("ReadThroughCache")
             val toMutableAttributes = symbol("toMutableAttributes")
             val emptyAttributes = symbol("emptyAttributes")
         }
@@ -204,6 +205,7 @@ object RuntimeTypes {
 
         object Net : RuntimeTypePackage(KotlinDependency.CORE, "net") {
             val Host = symbol("Host")
+            val Scheme = symbol("Scheme")
 
             object Url : RuntimeTypePackage(KotlinDependency.CORE, "net.url") {
                 val QueryParameters = symbol("QueryParameters")
@@ -251,6 +253,10 @@ object RuntimeTypes {
                 val Url = symbol("Url")
             }
         }
+
+        object Region : RuntimeTypePackage(KotlinDependency.SMITHY_CLIENT, "region") {
+            val RegionProvider = symbol("RegionProvider")
+        }
     }
 
     object Serde : RuntimeTypePackage(KotlinDependency.SERDE) {
@@ -374,6 +380,7 @@ object RuntimeTypes {
             val BearerTokenAuthScheme = symbol("BearerTokenAuthScheme")
             val BearerTokenProviderConfig = symbol("BearerTokenProviderConfig")
             val BearerTokenProvider = symbol("BearerTokenProvider")
+
             val BearerToken = symbol("BearerToken")
             val EnvironmentBearerTokenProvider = symbol("EnvironmentBearerTokenProvider")
 
@@ -387,6 +394,7 @@ object RuntimeTypes {
             val mergeAuthOptions = symbol("mergeAuthOptions")
             val sigV4 = symbol("sigV4")
             val sigV4A = symbol("sigV4A")
+            val SignHttpRequest = symbol("SignHttpRequest")
         }
 
         object AwsSigningCrt : RuntimeTypePackage(KotlinDependency.AWS_SIGNING_CRT) {
@@ -453,8 +461,8 @@ object RuntimeTypes {
         val RestJsonErrorDeserializer = symbol("RestJsonErrorDeserializer")
     }
     object AwsXmlProtocols : RuntimeTypePackage(KotlinDependency.AWS_XML_PROTOCOLS) {
-        val parseRestXmlErrorResponseNoSuspend = symbol("parseRestXmlErrorResponseNoSuspend")
-        val parseEc2QueryErrorResponseNoSuspend = symbol("parseEc2QueryErrorResponseNoSuspend")
+        val parseRestXmlErrorResponse = symbol("parseRestXmlErrorResponse")
+        val parseEc2QueryErrorResponse = symbol("parseEc2QueryErrorResponse")
     }
 
     object SmithyRpcV2Protocols : RuntimeTypePackage(KotlinDependency.SMITHY_RPCV2_PROTOCOLS) {
@@ -486,4 +494,134 @@ object RuntimeTypes {
 
         val sign = symbol("sign")
     }
+
+    object KtorServerCore : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_CORE) {
+        val embeddedServer = symbol("embeddedServer", "engine")
+        val EmbeddedServerType = symbol("EmbeddedServer", "engine")
+        val ApplicationEngineFactory = symbol("ApplicationEngineFactory", "engine")
+        val connector = symbol("connector", "engine")
+
+        val Application = symbol("Application", "application")
+        val ApplicationCallClass = symbol("ApplicationCall", "application")
+        val ApplicationStarting = symbol("ApplicationStarting", "application")
+        val ApplicationStarted = symbol("ApplicationStarted", "application")
+        val ApplicationStopping = symbol("ApplicationStopping", "application")
+        val ApplicationStopped = symbol("ApplicationStopped", "application")
+        val ApplicationCreateRouteScopedPlugin = symbol("createRouteScopedPlugin", "application")
+        val ApplicationRouteScopedPlugin = symbol("RouteScopedPlugin", "application")
+        val applicationCall = symbol("call", "application")
+        val install = symbol("install", "application")
+
+        val BadRequestException = symbol("BadRequestException", "plugins")
+    }
+
+    object KtorServerUtils : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_UTILS) {
+        val AttributeKey = symbol("AttributeKey", "util")
+    }
+
+    object KtorServerRouting : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_CORE) {
+        val routing = symbol("routing", "routing")
+        val route = symbol("route", "routing")
+        val get = symbol("get", "routing")
+        val post = symbol("post", "routing")
+        val put = symbol("put", "routing")
+        val delete = symbol("delete", "routing")
+        val patch = symbol("patch", "routing")
+        val head = symbol("head", "routing")
+        val options = symbol("options", "routing")
+
+        val requestReceive = symbol("receive", "request")
+        val requestUri = symbol("uri", "request")
+        val requestHeader = symbol("header", "request")
+        val requestHttpMethod = symbol("httpMethod", "request")
+        val requestApplicationRequest = symbol("ApplicationRequest", "request")
+        val requestContentLength = symbol("contentLength", "request")
+        val requestContentType = symbol("contentType", "request")
+        val requestAcceptItems = symbol("acceptItems", "request")
+        val requestPath = symbol("path", "request")
+
+        val responseResponse = symbol("respond", "response")
+        val responseResponseText = symbol("respondText", "response")
+        val responseRespondBytes = symbol("respondBytes", "response")
+    }
+
+    object KtorServerNetty : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_NETTY) {
+        val Netty = symbol("Netty")
+        val Configuration = symbol("Configuration", "NettyApplicationEngine")
+    }
+
+    object KtorServerCio : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_CIO) {
+        val CIO = symbol("CIO")
+        val Configuration = symbol("Configuration", "CIOApplicationEngine")
+    }
+
+    object KtorServerJettyJakarta : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_JETTY_JAKARTA) {
+        val Jetty = symbol("Jetty")
+        val Configuration = symbol("Configuration", "JettyApplicationEngineBase")
+    }
+
+    object KtorServerHttp : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_HTTP) {
+        val ContentType = symbol("ContentType")
+        val HttpStatusCode = symbol("HttpStatusCode")
+        val parseAndSortHeader = symbol("parseAndSortHeader")
+        val HttpHeaders = symbol("HttpHeaders")
+        val HeadersBuilder = symbol("HeadersBuilder")
+        val Parameters = symbol("Parameters")
+        val Cbor = symbol("Cbor", "ContentType.Application")
+        val Json = symbol("Json", "ContentType.Application")
+        val Any = symbol("Any", "ContentType.Application")
+        val OctetStream = symbol("OctetStream", "ContentType.Application")
+        val PlainText = symbol("Plain", "ContentType.Text")
+    }
+
+    object KtorServerLogging : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_LOGGING) {
+        val CallLogging = symbol("CallLogging")
+    }
+
+    object KtorServerBodyLimit : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_BODY_LIMIT) {
+        val RequestBodyLimit = symbol("RequestBodyLimit", "bodylimit")
+        val PayloadTooLargeException = symbol("PayloadTooLargeException")
+    }
+
+    object KtorLoggingSlf4j : RuntimeTypePackage(KotlinDependency.KTOR_LOGGING_SLF4J) {
+        val Level = symbol("Level", "event")
+        val LoggerFactory = symbol("LoggerFactory")
+        val ROOT_LOGGER_NAME = symbol("ROOT_LOGGER_NAME", "Logger")
+    }
+
+    object KtorLoggingLogback : RuntimeTypePackage(KotlinDependency.KTOR_LOGGING_LOGBACK) {
+        val Level = symbol("Level", "classic")
+        val LoggerContext = symbol("LoggerContext", "classic")
+    }
+
+    object KtorServerStatusPage : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_STATUS_PAGE) {
+        val StatusPages = symbol("StatusPages")
+        val exception = symbol("exception")
+    }
+
+    object KtorServerAuth : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_AUTH) {
+        val Authentication = symbol("Authentication")
+        val authenticate = symbol("authenticate")
+        val Principal = symbol("Principal")
+        val bearer = symbol("bearer")
+        val AuthenticationConfig = symbol("AuthenticationConfig")
+        val AuthenticationProvider = symbol("AuthenticationProvider")
+        val AuthenticationFailedCause = symbol("AuthenticationFailedCause")
+        val AuthenticationContext = symbol("AuthenticationContext")
+        val AuthenticationStrategy = symbol("AuthenticationStrategy")
+    }
+
+    object KtorServerDoubleReceive : RuntimeTypePackage(KotlinDependency.KTOR_SERVER_DOUBLE_RECEIVE) {
+        val DoubleReceive = symbol("DoubleReceive")
+    }
+
+    object KotlinxCborSerde : RuntimeTypePackage(KotlinDependency.KOTLINX_CBOR_SERDE) {
+        val Serializable = symbol("Serializable")
+        val Cbor = symbol("Cbor", "cbor")
+        val encodeToByteArray = symbol("encodeToByteArray")
+    }
+
+    object KotlinxJsonSerde : RuntimeTypePackage(KotlinDependency.KOTLINX_JSON_SERDE) {
+        val Json = symbol("Json")
+    }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/KotlinTypes.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/KotlinTypes.kt
index 6d2384584e..5eef2a0ef7 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/KotlinTypes.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/lang/KotlinTypes.kt
@@ -117,6 +117,7 @@ object KotlinTypes {
         val Duration = stdlibSymbol("Duration")
         val milliseconds = stdlibSymbol("milliseconds", "time.Duration.Companion")
         val minutes = stdlibSymbol("minutes", "time.Duration.Companion")
+        val seconds = stdlibSymbol("seconds", "time.Duration.Companion")
     }
 
     object Coroutines {
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
index aa308c5343..73c789e823 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionBaseClassGenerator.kt
@@ -10,7 +10,6 @@ import software.amazon.smithy.codegen.core.Symbol
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.core.*
 import software.amazon.smithy.kotlin.codegen.integration.SectionId
-import software.amazon.smithy.kotlin.codegen.integration.SectionKey
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.namespace
 import software.amazon.smithy.model.knowledge.TopDownIndex
@@ -31,12 +30,10 @@ object ExceptionBaseClassGenerator {
     /**
      * Defines a section in which code can be added to the body of the base exception type.
      */
-    object ExceptionBaseClassSection : SectionId {
-        val CodegenContext: SectionKey<CodegenContext> = SectionKey("CodegenContext")
-    }
+    object ExceptionBaseClassSection : SectionId
 
     fun render(ctx: CodegenContext, writer: KotlinWriter) {
-        writer.declareSection(ExceptionBaseClassSection, mapOf(ExceptionBaseClassSection.CodegenContext to ctx)) {
+        writer.declareSection(ExceptionBaseClassSection) {
             ServiceExceptionBaseClassGenerator().render(ctx, writer)
         }
     }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
index 07f7541a06..3b11dd16d4 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/GradleGenerator.kt
@@ -6,7 +6,11 @@ package software.amazon.smithy.kotlin.codegen.rendering
 
 import software.amazon.smithy.build.FileManifest
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
-import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.core.InlineCodeWriter
+import software.amazon.smithy.kotlin.codegen.core.InlineCodeWriterFormatter
+import software.amazon.smithy.kotlin.codegen.core.KOTLIN_COMPILER_VERSION
+import software.amazon.smithy.kotlin.codegen.core.KotlinDependency
+import software.amazon.smithy.kotlin.codegen.core.SERIALIZATION_PLUGIN
 import software.amazon.smithy.utils.AbstractCodeWriter
 
 // Determines the jvmTarget version emitted to the build file
@@ -27,6 +31,7 @@ fun writeGradleBuild(
 
     val isKmp = settings.build.generateMultiplatformProject
     val isRootModule = settings.build.generateFullProject
+    val generateServiceProject = settings.build.generateServiceProject
 
     val annotationRenderer: InlineCodeWriter = {
         val annotations = settings.build.optInAnnotations ?: emptyList()
@@ -46,12 +51,18 @@ fun writeGradleBuild(
         val pluginName = if (isKmp) "multiplatform" else "jvm"
 
         write(
-            "kotlin(\"$pluginName\") #W",
+            "kotlin(\"$pluginName\") #W \n #W",
             { w: AbstractCodeWriter<*> ->
                 if (isRootModule) {
                     w.write("version #S", KOTLIN_COMPILER_VERSION)
                 }
             },
+            { w: AbstractCodeWriter<*> ->
+                if (generateServiceProject) {
+                    w.write("application")
+                    w.write("kotlin(#S) version #S", "plugin.serialization", SERIALIZATION_PLUGIN)
+                }
+            },
         )
     }
 
@@ -67,10 +78,12 @@ fun writeGradleBuild(
         else -> renderJvmGradleBuild(
             writer,
             isRootModule,
+            generateServiceProject,
             dependencies,
             pluginsBodyRenderer,
             repositoryRenderer,
             annotationRenderer,
+            applicationRenderer("${settings.pkg.name}.MainKt"),
         )
     }
 
@@ -134,7 +147,7 @@ fun renderRootJvmPluginConfig(writer: GradleWriter) {
         """
             jvm {
                 compilations.all {
-                    kotlinOptions.jvmTarget = #S
+                    compilerOptions.jvmTarget = #S
                 }
                 testRuns["test"].executionTask.configure {
                     useJUnitPlatform()
@@ -155,10 +168,12 @@ fun renderRootJvmPluginConfig(writer: GradleWriter) {
 fun renderJvmGradleBuild(
     writer: GradleWriter,
     isRootModule: Boolean,
+    generateServiceProject: Boolean,
     dependencies: List<KotlinDependency>,
     pluginsRenderer: InlineCodeWriter,
     repositoryRenderer: InlineCodeWriter,
     annotationRenderer: InlineCodeWriter,
+    applicationRenderer: InlineCodeWriter,
 ) {
     writer.write(
         """
@@ -166,6 +181,8 @@ fun renderJvmGradleBuild(
             #W
         }
 
+        #W
+        
         #W
 
         dependencies {
@@ -196,6 +213,7 @@ fun renderJvmGradleBuild(
         """.trimIndent(),
         pluginsRenderer,
         { w: GradleWriter -> if (isRootModule) repositoryRenderer(w) },
+        { w: GradleWriter -> if (generateServiceProject) applicationRenderer(w) },
         { w: GradleWriter -> renderDependencies(w, scope = Scope.SOURCE, isKmp = false, dependencies = dependencies) },
         annotationRenderer,
         { w: GradleWriter -> if (isRootModule) w.write("explicitApi()") },
@@ -245,6 +263,16 @@ private val repositoryRenderer: InlineCodeWriter = {
     )
 }
 
+private fun applicationRenderer(mainClass: String): InlineCodeWriter = {
+    write(
+        """
+            application {
+                mainClass.set("$mainClass")
+            }
+        """.trimIndent(),
+    )
+}
+
 class GradleWriter(parent: GradleWriter? = null) : AbstractCodeWriter<GradleWriter>() {
     init {
         trimBlankLines(parent?.trimBlankLines ?: 1)
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
similarity index 55%
rename from codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt
rename to codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
index 73b6e434da..2d21de0577 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGenerator.kt
@@ -12,12 +12,11 @@ import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.model.buildSymbol
 import software.amazon.smithy.kotlin.codegen.model.expectShape
 import software.amazon.smithy.kotlin.codegen.model.expectTrait
-import software.amazon.smithy.kotlin.codegen.rendering.endpoints.EndpointResolverAdapterGenerator
 import software.amazon.smithy.kotlin.codegen.rendering.endpoints.SdkEndpointBuiltinIntegration
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ServiceShape
 
-class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
+class DefaultEndpointDiscovererGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
     private val symbol = symbolFor(ctx.settings)
     private val service = ctx.model.expectShape<ServiceShape>(ctx.settings.service)
     private val clientSymbol = ctx.symbolProvider.toSymbol(service)
@@ -30,58 +29,47 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
     companion object {
         fun symbolFor(settings: KotlinSettings): Symbol = buildSymbol {
             val clientName = clientName(settings.sdkId)
-            name = "${clientName}EndpointDiscoverer"
+            name = "Default${clientName}EndpointDiscoverer"
             namespace = "${settings.pkg.name}.endpoints"
         }
     }
 
     fun render() {
         delegator.applyFileWriter(symbol) {
+            val service = clientName(ctx.settings.sdkId)
             dokka(
                 """
-                    A class which looks up specific endpoints for ${ctx.settings.sdkId} calls via the `$operationName`
-                    API. These unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent
-                    calls.
+                    A class which looks up specific endpoints for $service calls via the `$operationName` API. These
+                    unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent calls.
+                    @param cache An [ExpiringKeyedCache] implementation used to cache discovered hosts
                 """.trimIndent(),
             )
+
             withBlock(
-                "#L class #T {",
+                "#1L class #2T(#1L val cache: #3T<DiscoveryParams, #4T> = #5T(10.#6T)) : #7T {",
                 "}",
                 ctx.settings.api.visibility,
                 symbol,
+                RuntimeTypes.Core.Collections.ExpiringKeyedCache,
+                RuntimeTypes.Core.Net.Host,
+                RuntimeTypes.Core.Collections.PeriodicSweepCache,
+                KotlinTypes.Time.minutes,
+                EndpointDiscovererInterfaceGenerator.symbolFor(ctx.settings),
             ) {
-                write(
-                    "private val cache = #T<DiscoveryParams, #T>(10.#T, #T.System)",
-                    RuntimeTypes.Core.Collections.ReadThroughCache,
-                    RuntimeTypes.Core.Net.Host,
-                    KotlinTypes.Time.minutes,
-                    RuntimeTypes.Core.Clock,
-                )
-                write("")
                 renderAsEndpointResolver()
                 write("")
-                renderDiscoverHost()
-                write("")
                 renderInvalidate()
             }
-            write("")
-            write(
-                """private val discoveryParamsKey = #T<DiscoveryParams>("DiscoveryParams")""",
-                RuntimeTypes.Core.Collections.AttributeKey,
-            )
-            write("private data class DiscoveryParams(private val region: String?, private val identity: String)")
         }
     }
 
     private fun KotlinWriter.renderAsEndpointResolver() {
         withBlock(
-            "internal fun asEndpointResolver(client: #T, delegate: #T) = #T { request ->",
+            "override fun asEndpointResolver(client: #1T, delegate: #2T): #2T = #2T { request ->",
             "}",
             clientSymbol,
-            EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             RuntimeTypes.HttpClient.Operation.EndpointResolver,
         ) {
-            // Backported from https://github.com/smithy-lang/smithy-kotlin/pull/1221; replace when merging v1.5 to main
             withBlock("if (client.config.#L == null) {", "}", SdkEndpointBuiltinIntegration.EndpointUrlProp.propertyName) {
                 write("val identity = request.identity")
                 write(
@@ -90,7 +78,7 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
                 )
                 write("")
                 write("val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)")
-                write("request.context[discoveryParamsKey] = cacheKey")
+                write("request.context[DiscoveryParamsKey] = cacheKey")
                 write("val discoveredHost = cache.get(cacheKey) { discoverHost(client) }")
                 write("")
                 write("val originalEndpoint = delegate.resolve(request)")
@@ -99,6 +87,7 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
                     write("originalEndpoint.headers,")
                     write("originalEndpoint.attributes,")
                 }
+
                 // If user manually specifies endpointUrl, skip endpoint discovery
                 closeAndOpenBlock("} else {")
                 write("delegate.resolve(request)")
@@ -106,34 +95,9 @@ class EndpointDiscovererGenerator(private val ctx: CodegenContext, private val d
         }
     }
 
-    private fun KotlinWriter.renderDiscoverHost() {
-        openBlock(
-            "private suspend fun discoverHost(client: #T): #T<#T> =",
-            clientSymbol,
-            RuntimeTypes.Core.Utils.ExpiringValue,
-            RuntimeTypes.Core.Net.Host,
-        )
-        // ASSUMPTION No services which use discovery include parameters to the EP operation (despite being
-        // possible according to the Smithy spec).
-        write("client.#L()", operationName)
-        indent()
-        write(".endpoints")
-        withBlock("?.map { ep -> #T(", ")}", RuntimeTypes.Core.Utils.ExpiringValue) {
-            write("#T.parse(ep.address!!),", RuntimeTypes.Core.Net.Host)
-            write("#T.now() + ep.cachePeriodInMinutes.#T,", RuntimeTypes.Core.Instant, KotlinTypes.Time.minutes)
-        }
-        write("?.firstOrNull()")
-        write(
-            """?: throw #T("Unable to discover any endpoints when invoking #L!")""",
-            RuntimeTypes.SmithyClient.Endpoints.EndpointProviderException,
-            operationName,
-        )
-        dedent(2)
-    }
-
     private fun KotlinWriter.renderInvalidate() {
-        withBlock("internal suspend fun invalidate(context: #T) {", "}", RuntimeTypes.Core.ExecutionContext) {
-            write("context.getOrNull(discoveryParamsKey)?.let { cache.invalidate(it) }")
+        withBlock("override public suspend fun invalidate(context: #T) {", "}", RuntimeTypes.Core.ExecutionContext) {
+            write("context.getOrNull(DiscoveryParamsKey)?.let { cache.invalidate(it) }")
         }
     }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt
new file mode 100644
index 0000000000..ddc70752db
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGenerator.kt
@@ -0,0 +1,94 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import software.amazon.smithy.aws.traits.clientendpointdiscovery.ClientEndpointDiscoveryTrait
+import software.amazon.smithy.codegen.core.Symbol
+import software.amazon.smithy.kotlin.codegen.KotlinSettings
+import software.amazon.smithy.kotlin.codegen.core.*
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+import software.amazon.smithy.kotlin.codegen.model.expectShape
+import software.amazon.smithy.kotlin.codegen.model.expectTrait
+import software.amazon.smithy.model.shapes.OperationShape
+import software.amazon.smithy.model.shapes.ServiceShape
+
+class EndpointDiscovererInterfaceGenerator(private val ctx: CodegenContext, private val delegator: KotlinDelegator) {
+    private val symbol = symbolFor(ctx.settings)
+    private val service = ctx.model.expectShape<ServiceShape>(ctx.settings.service)
+    private val clientSymbol = ctx.symbolProvider.toSymbol(service)
+    private val operationName = run {
+        val epDiscoveryTrait = service.expectTrait<ClientEndpointDiscoveryTrait>()
+        val operation = ctx.model.expectShape<OperationShape>(epDiscoveryTrait.operation)
+        operation.defaultName()
+    }
+
+    companion object {
+        fun symbolFor(settings: KotlinSettings): Symbol = buildSymbol {
+            val clientName = clientName(settings.sdkId)
+            name = "${clientName}EndpointDiscoverer"
+            namespace = "${settings.pkg.name}.endpoints"
+        }
+    }
+
+    fun render() {
+        delegator.applyFileWriter(symbol) {
+            dokka("Represents the logic for automatically discovering endpoints for ${ctx.settings.sdkId} calls")
+            withBlock(
+                "#L interface #T {",
+                "}",
+                ctx.settings.api.visibility,
+                symbol,
+            ) {
+                write(
+                    "#1L fun asEndpointResolver(client: #2T, delegate: #3T): #3T",
+                    ctx.settings.api.visibility,
+                    clientSymbol,
+                    RuntimeTypes.HttpClient.Operation.EndpointResolver,
+                )
+                write("")
+                renderDiscoverHost()
+                write("")
+                write("public suspend fun invalidate(context: #T)", RuntimeTypes.Core.ExecutionContext)
+            }
+            write("")
+            write(
+                "#L data class DiscoveryParams(private val region: String?, private val identity: String)",
+                ctx.settings.api.visibility,
+            )
+            write(
+                """#1L val DiscoveryParamsKey: #2T<DiscoveryParams> = #2T("DiscoveryParams")""",
+                ctx.settings.api.visibility,
+                RuntimeTypes.Core.Collections.AttributeKey,
+            )
+        }
+    }
+
+    private fun KotlinWriter.renderDiscoverHost() {
+        openBlock(
+            "#L suspend fun discoverHost(client: #T): #T<#T> =",
+            ctx.settings.api.visibility,
+            clientSymbol,
+            RuntimeTypes.Core.Utils.ExpiringValue,
+            RuntimeTypes.Core.Net.Host,
+        )
+        // ASSUMPTION No services which use discovery include parameters to the EP operation (despite being
+        // possible according to the Smithy spec).
+        write("client.#L()", operationName)
+        indent()
+        write(".endpoints")
+        withBlock("?.map { ep -> #T(", ")}", RuntimeTypes.Core.Utils.ExpiringValue) {
+            write("#T.parse(ep.address!!),", RuntimeTypes.Core.Net.Host)
+            write("#T.now() + ep.cachePeriodInMinutes.#T,", RuntimeTypes.Core.Instant, KotlinTypes.Time.minutes)
+        }
+        write("?.firstOrNull()")
+        write(
+            """?: throw #T("Unable to discover any endpoints when invoking #L!")""",
+            RuntimeTypes.SmithyClient.Endpoints.EndpointProviderException,
+            operationName,
+        )
+        dedent(2)
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
index 62906af4d7..4e8a7446a1 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegration.kt
@@ -22,26 +22,38 @@ import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.ServiceShape
 
 class EndpointDiscoveryIntegration : KotlinIntegration {
-    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> {
-        val endpointDiscoveryOptional = ctx
+    companion object {
+        const val CLIENT_CONFIG_NAME = "endpointDiscoverer"
+        const val ORDER: Byte = 0 // doesn't depend on any other integrations
+
+        fun isEnabledFor(model: Model, settings: KotlinSettings) = model
+            .expectShape<ServiceShape>(settings.service)
+            .hasTrait<ClientEndpointDiscoveryTrait>()
+
+        fun isOptionalFor(ctx: CodegenContext) = ctx
             .model
             .operationShapes
             .none { it.getTrait<ClientDiscoveredEndpointTrait>()?.isRequired == true }
-        val discovererSymbol = EndpointDiscovererGenerator.symbolFor(ctx.settings)
+    }
+
+    override fun additionalServiceConfigProps(ctx: CodegenContext): List<ConfigProperty> {
+        val endpointDiscoveryOptional = isOptionalFor(ctx)
+        val interfaceSymbol = EndpointDiscovererInterfaceGenerator.symbolFor(ctx.settings)
         return super.additionalServiceConfigProps(ctx) + listOf(
             ConfigProperty {
-                name = "endpointDiscoverer"
+                name = CLIENT_CONFIG_NAME
 
                 if (endpointDiscoveryOptional) {
                     documentation = """
-                        The endpoint discoverer for this client, if applicable. By default, no endpoint
-                        discovery is provided. To use endpoint discovery, set this to a valid
-                        [${discovererSymbol.name}] instance.
+                        The endpoint discoverer for this client, if applicable. By default, no endpoint discovery is
+                        provided. To use endpoint discovery, set this to a valid [${interfaceSymbol.name}] instance.
                     """.trimIndent()
-                    symbol = discovererSymbol.asNullable()
+                    symbol = interfaceSymbol.asNullable()
                 } else {
+                    val defaultImplSymbol = DefaultEndpointDiscovererGenerator.symbolFor(ctx.settings)
                     documentation = "The endpoint discoverer for this client"
-                    useSymbolWithNullableBuilder(discovererSymbol, "${discovererSymbol.name}()")
+                    additionalImports = listOf(defaultImplSymbol)
+                    useSymbolWithNullableBuilder(interfaceSymbol, "${defaultImplSymbol.name}()")
                 }
             },
         )
@@ -50,10 +62,11 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
     override fun customizeMiddleware(
         ctx: ProtocolGenerator.GenerationContext,
         resolved: List<ProtocolMiddleware>,
-    ): List<ProtocolMiddleware> = super.customizeMiddleware(ctx, resolved) + listOf(DiscoveredEndpointMiddleware)
+    ): List<ProtocolMiddleware> = resolved + DiscoveredEndpointErrorMiddleware
 
-    override fun enabledForService(model: Model, settings: KotlinSettings): Boolean =
-        model.expectShape<ServiceShape>(settings.service).hasTrait<ClientEndpointDiscoveryTrait>()
+    override fun enabledForService(model: Model, settings: KotlinSettings): Boolean = isEnabledFor(model, settings)
+
+    override val order = ORDER
 
     override val sectionWriters: List<SectionWriterBinding> = listOf(
         SectionWriterBinding(HttpProtocolClientGenerator.EndpointResolverAdapterBinding, ::renderEndpointResolver),
@@ -69,13 +82,15 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
             null -> writer.write("#L", previousValue)
 
             true -> writer.write(
-                "execution.endpointResolver = config.endpointDiscoverer.asEndpointResolver(this@#L, #T(config))",
+                "execution.endpointResolver = config.#L.asEndpointResolver(this@#L, #T(config))",
+                CLIENT_CONFIG_NAME,
                 defaultClientName,
                 EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             )
 
             false -> writer.write(
-                "execution.endpointResolver = config.endpointDiscoverer?.asEndpointResolver(this@#1L, #2T(config)) ?: #2T(config)",
+                "execution.endpointResolver = config.#1L?.asEndpointResolver(this@#2L, #3T(config)) ?: #3T(config)",
+                CLIENT_CONFIG_NAME,
                 defaultClientName,
                 EndpointResolverAdapterGenerator.getSymbol(ctx.settings),
             )
@@ -83,30 +98,29 @@ class EndpointDiscoveryIntegration : KotlinIntegration {
     }
 
     override fun writeAdditionalFiles(ctx: CodegenContext, delegator: KotlinDelegator) {
-        EndpointDiscovererGenerator(ctx, delegator).render()
-        super.writeAdditionalFiles(ctx, delegator)
+        EndpointDiscovererInterfaceGenerator(ctx, delegator).render()
+
+        if (!isOptionalFor(ctx)) {
+            DefaultEndpointDiscovererGenerator(ctx, delegator).render()
+        }
     }
 }
 
-private object DiscoveredEndpointMiddleware : ProtocolMiddleware {
-    override val name: String = "DiscoveredEndpointMiddleware"
+private object DiscoveredEndpointErrorMiddleware : ProtocolMiddleware {
+    override val name: String = "DiscoveredEndpointErrorMiddleware"
 
     override fun isEnabledFor(ctx: ProtocolGenerator.GenerationContext, op: OperationShape): Boolean =
-        op.getTrait<ClientEndpointDiscoveryTrait>()?.optionalError?.getOrNull() != null &&
+        ctx.service.getTrait<ClientEndpointDiscoveryTrait>()?.optionalError?.getOrNull() != null &&
             op.hasTrait<ClientDiscoveredEndpointTrait>()
 
     override fun render(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, writer: KotlinWriter) {
-        val interceptor = buildSymbol {
-            name = "DiscoveredEndpointErrorInterceptor"
-            namespace(KotlinDependency.HTTP_CLIENT, "aws.smithy.kotlin.runtime.http.interceptors")
-        }
-
         val errorShapeId = ctx.service.expectTrait<ClientEndpointDiscoveryTrait>().optionalError.get()
         val errorShape = ctx.model.expectShape(errorShapeId)
         val errorSymbol = ctx.symbolProvider.toSymbol(errorShape)
         writer.write(
-            "config.endpointDiscoverer?.let { op.interceptors.add(#T(#T, it::invalidate)) }",
-            interceptor,
+            "config.#L?.let { op.interceptors.add(#T(#T::class, it::invalidate)) }",
+            EndpointDiscoveryIntegration.CLIENT_CONFIG_NAME,
+            RuntimeTypes.HttpClient.Interceptors.DiscoveredEndpointErrorInterceptor,
             errorSymbol,
         )
     }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingProtocolGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingProtocolGenerator.kt
index 0587f2ed24..4dae6e5c7e 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingProtocolGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingProtocolGenerator.kt
@@ -120,6 +120,11 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         httpOperations.forEach { operation ->
             generateOperationSerializer(ctx, operation)
         }
+
+        if (ctx.settings.build.generateServiceProject) {
+            val modeledErrors = httpOperations.flatMap { it.errors }.map { ctx.model.expectShape(it) as StructureShape }.toSet()
+            modeledErrors.forEach { generateExceptionSerializer(ctx, it) }
+        }
     }
 
     private fun generateDeserializers(ctx: ProtocolGenerator.GenerationContext) {
@@ -131,15 +136,22 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         }
 
         // generate HttpDeserialize for exception types
-        val modeledErrors = httpOperations.flatMap { it.errors }.map { ctx.model.expectShape(it) as StructureShape }.toSet()
-        modeledErrors.forEach { generateExceptionDeserializer(ctx, it) }
+        if (!ctx.settings.build.generateServiceProject) {
+            val modeledErrors = httpOperations.flatMap { it.errors }.map { ctx.model.expectShape(it) as StructureShape }.toSet()
+            modeledErrors.forEach { generateExceptionDeserializer(ctx, it) }
+        }
     }
 
     override fun generateProtocolClient(ctx: ProtocolGenerator.GenerationContext) {
-        val symbol = ctx.symbolProvider.toSymbol(ctx.service)
-        ctx.delegator.useFileWriter("Default${symbol.name}.kt", ctx.settings.pkg.name) { writer ->
-            val clientGenerator = getHttpProtocolClientGenerator(ctx)
-            clientGenerator.render(writer)
+        if (ctx.settings.build.generateServiceProject) {
+            require(protocolName in listOf("smithyRpcv2cbor", "awsRestjson1")) { "service project accepts only Cbor or JSON protocol" }
+        }
+        if (!ctx.settings.build.generateServiceProject) {
+            val symbol = ctx.symbolProvider.toSymbol(ctx.service)
+            ctx.delegator.useFileWriter("Default${symbol.name}.kt", ctx.settings.pkg.name) { writer ->
+                val clientGenerator = getHttpProtocolClientGenerator(ctx)
+                clientGenerator.render(writer)
+            }
         }
         generateSerializers(ctx)
         generateDeserializers(ctx)
@@ -149,12 +161,17 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
      * Generate request serializer (HttpSerialize) for an operation
      */
     private fun generateOperationSerializer(ctx: ProtocolGenerator.GenerationContext, op: OperationShape) {
-        if (!op.input.isPresent) {
+        val serializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.output
+        } else {
+            op.input
+        }
+        if (!serializationTarget.isPresent) {
             return
         }
 
-        val inputShape = ctx.model.expectShape(op.input.get())
-        val inputSymbol = ctx.symbolProvider.toSymbol(inputShape)
+        val serializationShape = ctx.model.expectShape(serializationTarget.get())
+        val serializationSymbol = ctx.symbolProvider.toSymbol(serializationShape)
 
         // operation input shapes could be re-used across one or more operations. The protocol details may
         // be different though (e.g. uri/method). We need to generate a serializer/deserializer per/operation
@@ -164,7 +181,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             name = op.serializerName()
             namespace = ctx.settings.pkg.serde
 
-            reference(inputSymbol, SymbolReference.ContextOption.DECLARE)
+            reference(serializationSymbol, SymbolReference.ContextOption.DECLARE)
         }
         val operationSerializerSymbols = setOf(
             RuntimeTypes.Http.HttpBody,
@@ -175,27 +192,50 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         val serdeMeta = HttpSerdeMeta(op.isInputEventStream(ctx.model))
 
         ctx.delegator.useSymbolWriter(serializerSymbol) { writer ->
-            writer
-                .addImport(operationSerializerSymbols)
-                .write("")
-                .openBlock("internal class #T: #T.#L<#T> {", serializerSymbol, RuntimeTypes.HttpClient.Operation.HttpSerializer, serdeMeta.variantName, inputSymbol)
-                .call {
-                    val modifier = if (serdeMeta.isStreaming) "suspend " else ""
-                    writer.openBlock(
-                        "override #Lfun serialize(context: #T, input: #T): #T {",
-                        modifier,
-                        RuntimeTypes.Core.ExecutionContext,
-                        inputSymbol,
-                        RuntimeTypes.Http.Request.HttpRequestBuilder,
-                    )
-                        .write("val builder = #T()", RuntimeTypes.Http.Request.HttpRequestBuilder)
-                        .call {
-                            renderHttpSerialize(ctx, op, writer)
-                        }
-                        .write("return builder")
-                        .closeBlock("}")
-                }
-                .closeBlock("}")
+            if (ctx.settings.build.generateServiceProject) {
+                val serializerResultSymbol = getHttpSerializerResultSymbol(protocolName)
+                val defaultResponse = getHttpSerializerDefaultResponse(protocolName)
+
+                writer
+                    .openBlock("internal class #T {", serializerSymbol)
+                    .call {
+                        writer.openBlock(
+                            "public fun serialize(context: #T, input: #T): #T {",
+                            RuntimeTypes.Core.ExecutionContext,
+                            serializationSymbol,
+                            serializerResultSymbol,
+                        )
+                            .write("var response: #T = $defaultResponse", serializerResultSymbol)
+                            .call {
+                                renderSerializeHttpBody(ctx, op, writer)
+                            }
+                            .write("return response")
+                            .closeBlock("}")
+                    }
+                    .closeBlock("}")
+            } else {
+                writer
+                    .addImport(operationSerializerSymbols)
+                    .write("")
+                    .openBlock("internal class #T: #T.#L<#T> {", serializerSymbol, RuntimeTypes.HttpClient.Operation.HttpSerializer, serdeMeta.variantName, serializationSymbol)
+                    .call {
+                        val modifier = if (serdeMeta.isStreaming) "suspend " else ""
+                        writer.openBlock(
+                            "override #Lfun serialize(context: #T, input: #T): #T {",
+                            modifier,
+                            RuntimeTypes.Core.ExecutionContext,
+                            serializationSymbol,
+                            RuntimeTypes.Http.Request.HttpRequestBuilder,
+                        )
+                            .write("val builder = #T()", RuntimeTypes.Http.Request.HttpRequestBuilder)
+                            .call {
+                                renderHttpSerialize(ctx, op, writer)
+                            }
+                            .write("return builder")
+                            .closeBlock("}")
+                    }
+                    .closeBlock("}")
+            }
         }
     }
 
@@ -206,7 +246,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
     ) {
         val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
         val httpTrait = resolver.httpTrait(op)
-        val requestBindings = resolver.requestBindings(op)
+        val bindings = resolver.requestBindings(op)
 
         writer
             .addImport(RuntimeTypes.Core.ExecutionContext)
@@ -218,17 +258,17 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     renderUri(ctx, op, writer)
 
                     // Query Parameters
-                    renderQueryParameters(ctx, httpTrait, requestBindings, writer)
+                    renderQueryParameters(ctx, httpTrait, bindings, writer)
                 }
             }
             .write("")
             .call {
                 // headers
-                val headerBindings = requestBindings
+                val headerBindings = bindings
                     .filter { it.location == HttpBinding.Location.HEADER }
                     .sortedBy { it.memberName }
 
-                val prefixHeaderBindings = requestBindings
+                val prefixHeaderBindings = bindings
                     .filter { it.location == HttpBinding.Location.PREFIX_HEADERS }
 
                 if (headerBindings.isNotEmpty() || prefixHeaderBindings.isNotEmpty()) {
@@ -256,6 +296,42 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             }
     }
 
+    /**
+     * Generate HttpSerialize for a modeled error (exception)
+     */
+    private fun generateExceptionSerializer(ctx: ProtocolGenerator.GenerationContext, shape: StructureShape) {
+        val serializationSymbol = ctx.symbolProvider.toSymbol(shape)
+
+        val serializerSymbol = buildSymbol {
+            val deserializerName = "${serializationSymbol.name}Serializer"
+            definitionFile = "$deserializerName.kt"
+            name = deserializerName
+            namespace = ctx.settings.pkg.serde
+            reference(serializationSymbol, SymbolReference.ContextOption.DECLARE)
+        }
+
+        ctx.delegator.useSymbolWriter(serializerSymbol) { writer ->
+            val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
+            val bindings = resolver.responseBindings(shape)
+            val serializerResultSymbol = getHttpSerializerResultSymbol(protocolName)
+            val defaultResponse = getHttpSerializerDefaultResponse(protocolName)
+            writer.withBlock("internal class #T {", "}", serializerSymbol) {
+                writer.openBlock(
+                    "public fun serialize(context: #T, input: #T): #T {",
+                    RuntimeTypes.Core.ExecutionContext,
+                    serializationSymbol,
+                    serializerResultSymbol,
+                )
+                    .write("var response: #T = $defaultResponse", serializerResultSymbol)
+                    .call {
+                        renderExceptionSerializeBody(ctx, serializationSymbol, bindings, writer)
+                    }
+                    .write("return response")
+                    .closeBlock("}")
+            }
+        }
+    }
+
     /**
      * Calls the operation body serializer function and binds the results to `builder.body`.
      * By default if no members are bound to the body this function renders nothing.
@@ -263,23 +339,57 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
      */
     protected open fun renderSerializeHttpBody(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, writer: KotlinWriter) {
         val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
-        if (!resolver.hasHttpBody(op)) return
+        if (ctx.settings.build.generateServiceProject) {
+            if (!resolver.hasHttpResponseBody(op)) return
+        } else {
+            if (!resolver.hasHttpRequestBody(op)) return
+        }
 
         // payload member(s)
-        val requestBindings = resolver.requestBindings(op)
-        val httpPayload = requestBindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
+        val bindings = if (ctx.settings.build.generateServiceProject) {
+            resolver.responseBindings(op)
+        } else {
+            resolver.requestBindings(op)
+        }
+        val httpPayload = bindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
         if (httpPayload != null) {
             renderExplicitHttpPayloadSerializer(ctx, httpPayload, writer)
         } else {
-            val documentMembers = requestBindings.filterDocumentBoundMembers()
+            val documentMembers = bindings.filterDocumentBoundMembers()
             // Unbound document members that should be serialized into the document format for the protocol.
             // delegate to the generate operation body serializer function
             val sdg = structuredDataSerializer(ctx)
             val opBodySerializerFn = sdg.operationSerializer(ctx, op, documentMembers)
             writer.write("val payload = #T(context, input)", opBodySerializerFn)
-            writer.write("builder.body = #T.fromBytes(payload)", RuntimeTypes.Http.HttpBody)
+            if (ctx.settings.build.generateServiceProject) {
+                writer.write("response = payload.decodeToString()")
+            } else {
+                writer.write("builder.body = #T.fromBytes(payload)", RuntimeTypes.Http.HttpBody)
+            }
+        }
+        if (!ctx.settings.build.generateServiceProject) {
+            renderContentTypeHeader(ctx, op, writer, resolver)
         }
-        renderContentTypeHeader(ctx, op, writer, resolver)
+    }
+
+    /**
+     * Calls the operation body serializer function and binds the results to `builder.body`.
+     * By default if no members are bound to the body this function renders nothing.
+     * If there is a payload to render it should be bound to `builder.body` when this function returns
+     */
+    protected open fun renderExceptionSerializeBody(
+        ctx: ProtocolGenerator.GenerationContext,
+        deserializationSymbol: Symbol,
+        bindings: List<HttpBindingDescriptor>,
+        writer: KotlinWriter,
+    ) {
+        val documentMembers = bindings.filterDocumentBoundMembers()
+        // Unbound document members that should be serialized into the document format for the protocol.
+        // delegate to the generate operation body serializer function
+        val sdg = structuredDataSerializer(ctx)
+        val exceptionBodySerializerFn = sdg.errorSerializer(ctx, deserializationSymbol.shape as StructureShape, documentMembers)
+        writer.write("val payload = #T(context, input)", exceptionBodySerializerFn)
+        writer.write("response = payload")
     }
 
     protected open fun renderContentTypeHeader(
@@ -303,24 +413,28 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
     ) {
         val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
         val httpTrait = resolver.httpTrait(op)
-        val requestBindings = resolver.requestBindings(op)
-        val pathBindings = requestBindings.filter { it.location == HttpBinding.Location.LABEL }
+        val bindings = if (ctx.settings.build.generateServiceProject) {
+            resolver.responseBindings(op)
+        } else {
+            resolver.requestBindings(op)
+        }
+        val pathBindings = bindings.filter { it.location == HttpBinding.Location.LABEL }
 
         if (pathBindings.isNotEmpty()) {
             // One of the few places we generate client side validation
             // httpLabel bindings must be non-null
             httpTrait.uri.segments.filter { it.isLabel || it.isGreedyLabel }.forEach { segment ->
-                val binding = pathBindings.find {
+                val bindings = pathBindings.find {
                     it.memberName == segment.content
                 } ?: throw CodegenException("failed to find corresponding member for httpLabel `${segment.content}`")
 
-                val memberSymbol = ctx.symbolProvider.toSymbol(binding.member)
+                val memberSymbol = ctx.symbolProvider.toSymbol(bindings.member)
                 if (memberSymbol.isNullable) {
-                    writer.write("""requireNotNull(input.#1L) { "#1L is bound to the URI and must not be null" }""", binding.member.defaultName())
+                    writer.write("""requireNotNull(input.#1L) { "#1L is bound to the URI and must not be null" }""", bindings.member.defaultName())
                 }
 
                 // check length trait if applicable
-                renderNonBlankGuard(ctx, binding.member, writer)
+                renderNonBlankGuard(ctx, bindings.member, writer)
             }
 
             if (httpTrait.uri.segments.isNotEmpty()) {
@@ -328,37 +442,37 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     httpTrait.uri.segments.forEach { segment ->
                         if (segment.isLabel || segment.isGreedyLabel) {
                             // spec dictates member name and label name MUST be the same
-                            val binding = pathBindings.find { binding ->
+                            val bindings = pathBindings.find { binding ->
                                 binding.memberName == segment.content
                             }
                                 ?: throw CodegenException("failed to find corresponding member for httpLabel `${segment.content}")
 
                             // shape must be string, number, boolean, or timestamp
-                            val targetShape = ctx.model.expectShape(binding.member.target)
-                            val memberSymbol = ctx.symbolProvider.toSymbol(binding.member)
+                            val targetShape = ctx.model.expectShape(bindings.member.target)
+                            val memberSymbol = ctx.symbolProvider.toSymbol(bindings.member)
                             val identifier = when {
                                 targetShape.isTimestampShape -> {
                                     addImport(RuntimeTypes.Core.TimestampFormat)
                                     val tsFormat = resolver.determineTimestampFormat(
-                                        binding.member,
+                                        bindings.member,
                                         HttpBinding.Location.LABEL,
                                         defaultTimestampFormat,
                                     )
                                     val nullCheck = if (memberSymbol.isNullable) "?" else ""
                                     val tsLabel = formatInstant(
-                                        "input.${binding.member.defaultName()}$nullCheck",
+                                        "input.${bindings.member.defaultName()}$nullCheck",
                                         tsFormat,
                                         forceString = true,
                                     )
                                     tsLabel
                                 }
 
-                                targetShape.isStringEnumShape -> "input.${binding.member.defaultName()}.value"
-                                targetShape.isIntEnumShape -> "input.${binding.member.defaultName()}.value.toString()"
+                                targetShape.isStringEnumShape -> "input.${bindings.member.defaultName()}.value"
+                                targetShape.isIntEnumShape -> "input.${bindings.member.defaultName()}.value.toString()"
 
-                                targetShape.isStringShape -> "input.${binding.member.defaultName()}"
+                                targetShape.isStringShape -> "input.${bindings.member.defaultName()}"
 
-                                else -> "input.${binding.member.defaultName()}.toString()"
+                                else -> "input.${bindings.member.defaultName()}.toString()"
                             }
 
                             val encodeFn =
@@ -397,17 +511,17 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
     private fun renderQueryParameters(
         ctx: ProtocolGenerator.GenerationContext,
         httpTrait: HttpTrait,
-        requestBindings: List<HttpBindingDescriptor>,
+        bindings: List<HttpBindingDescriptor>,
         writer: KotlinWriter,
     ) {
         // literals in the URI
         val queryLiterals = httpTrait.uri.queryLiterals
 
         // shape bindings
-        val queryBindings = requestBindings.filter { it.location == HttpBinding.Location.QUERY }
+        val queryBindings = bindings.filter { it.location == HttpBinding.Location.QUERY }
 
         // maps bound via httpQueryParams trait
-        val queryMapBindings = requestBindings.filter { it.location == HttpBinding.Location.QUERY_PARAMS }
+        val queryMapBindings = bindings.filter { it.location == HttpBinding.Location.QUERY_PARAMS }
 
         if (queryBindings.isEmpty() && queryLiterals.isEmpty() && queryMapBindings.isEmpty()) return
 
@@ -493,7 +607,11 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                 if (isBinaryStream) {
                     writer.write("builder.body = input.#L.#T()", memberName, RuntimeTypes.Http.toHttpBody)
                 } else {
-                    writer.write("builder.body = #T.fromBytes(input.#L)", RuntimeTypes.Http.HttpBody, memberName)
+                    if (ctx.settings.build.generateServiceProject) {
+                        writer.write("response = input.#L.decodeToString()", memberName)
+                    } else {
+                        writer.write("builder.body = #T.fromBytes(input.#L)", RuntimeTypes.Http.HttpBody, memberName)
+                    }
                 }
             }
 
@@ -503,29 +621,46 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                 } else {
                     memberName
                 }
-                writer.write("builder.body = #T.fromBytes(input.#L.#T())", RuntimeTypes.Http.HttpBody, contents, KotlinTypes.Text.encodeToByteArray)
+                if (ctx.settings.build.generateServiceProject) {
+                    writer.write("response = input.#L", contents)
+                } else {
+                    writer.write("builder.body = #T.fromBytes(input.#L.#T())", RuntimeTypes.Http.HttpBody, contents, KotlinTypes.Text.encodeToByteArray)
+                }
             }
 
             ShapeType.ENUM ->
-                writer.write(
-                    "builder.body = #T.fromBytes(input.#L.value.#T())",
-                    RuntimeTypes.Http.HttpBody,
-                    memberName,
-                    KotlinTypes.Text.encodeToByteArray,
-                )
+                if (ctx.settings.build.generateServiceProject) {
+                    writer.write("response = input.#L.value.toString()", memberName)
+                } else {
+                    writer.write(
+                        "builder.body = #T.fromBytes(input.#L.value.#T())",
+                        RuntimeTypes.Http.HttpBody,
+                        memberName,
+                        KotlinTypes.Text.encodeToByteArray,
+                    )
+                }
+
             ShapeType.INT_ENUM ->
-                writer.write(
-                    "builder.body = #T.fromBytes(input.#L.value.toString().#T())",
-                    RuntimeTypes.Http.HttpBody,
-                    memberName,
-                    KotlinTypes.Text.encodeToByteArray,
-                )
+                if (ctx.settings.build.generateServiceProject) {
+                    writer.write("response = input.#L.value.toString()", memberName)
+                } else {
+                    writer.write(
+                        "builder.body = #T.fromBytes(input.#L.value.toString().#T())",
+                        RuntimeTypes.Http.HttpBody,
+                        memberName,
+                        KotlinTypes.Text.encodeToByteArray,
+                    )
+                }
 
             ShapeType.STRUCTURE, ShapeType.UNION, ShapeType.DOCUMENT -> {
                 val sdg = structuredDataSerializer(ctx)
                 val payloadSerializerFn = sdg.payloadSerializer(ctx, binding.member)
                 writer.write("val payload = #T(input.#L)", payloadSerializerFn, memberName)
-                writer.write("builder.body = #T.fromBytes(payload)", RuntimeTypes.Http.HttpBody)
+                if (ctx.settings.build.generateServiceProject) {
+                    writer.write("response = payload.decodeToString()")
+                } else {
+                    writer.write("builder.body = #T.fromBytes(payload)", RuntimeTypes.Http.HttpBody)
+                }
             }
 
             else ->
@@ -538,12 +673,16 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
      * Generate request deserializer (HttpDeserialize) for an operation
      */
     private fun generateOperationDeserializer(ctx: ProtocolGenerator.GenerationContext, op: OperationShape) {
-        if (!op.output.isPresent) {
+        val deserializationBindings = if (ctx.settings.build.generateServiceProject) {
+            op.input
+        } else {
+            op.output
+        }
+        if (!deserializationBindings.isPresent) {
             return
         }
-
-        val outputShape = ctx.model.expectShape(op.output.get())
-        val outputSymbol = ctx.symbolProvider.toSymbol(outputShape)
+        val deserializationShape = ctx.model.expectShape(deserializationBindings.get())
+        val deserializationSymbol = ctx.symbolProvider.toSymbol(deserializationShape)
 
         // operation output shapes could be re-used across one or more operations. The protocol details may
         // be different though (e.g. uri/method). We need to generate a serializer/deserializer per/operation
@@ -554,29 +693,44 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             name = op.deserializerName()
             namespace = ctx.settings.pkg.serde
 
-            reference(outputSymbol, SymbolReference.ContextOption.DECLARE)
+            reference(deserializationSymbol, SymbolReference.ContextOption.DECLARE)
         }
 
         val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
-        val responseBindings = resolver.responseBindings(op)
+        val bindings = if (ctx.settings.build.generateServiceProject) {
+            resolver.requestBindings(op)
+        } else {
+            resolver.responseBindings(op)
+        }
 
         val serdeMeta = httpDeserializerInfo(ctx, op)
 
         ctx.delegator.useSymbolWriter(deserializerSymbol) { writer ->
-            writer
-                .write("")
-                .openBlock(
-                    "internal class #T: #T.#L<#T> {",
-                    deserializerSymbol,
-                    RuntimeTypes.HttpClient.Operation.HttpDeserializer,
-                    serdeMeta.variantName,
-                    outputSymbol,
-                )
-                .write("")
-                .call {
-                    renderHttpDeserialize(ctx, outputSymbol, responseBindings, serdeMeta, op, writer)
-                }
-                .closeBlock("}")
+            when (ctx.settings.build.generateServiceProject) {
+                true ->
+                    writer
+                        .write("")
+                        .openBlock(
+                            "internal class #T {",
+                            deserializerSymbol,
+                        )
+                        .write("")
+                        .call { renderServiceHttpDeserialize(ctx, deserializationSymbol, bindings, serdeMeta, op, writer) }
+                        .closeBlock("}")
+                false ->
+                    writer
+                        .write("")
+                        .openBlock(
+                            "internal class #T: #T.#L<#T> {",
+                            deserializerSymbol,
+                            RuntimeTypes.HttpClient.Operation.HttpDeserializer,
+                            serdeMeta.variantName,
+                            deserializationSymbol,
+                        )
+                        .write("")
+                        .call { renderHttpDeserialize(ctx, deserializationSymbol, bindings, serdeMeta, op, writer) }
+                        .closeBlock("}")
+            }
         }
     }
 
@@ -599,7 +753,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
      * Generate HttpDeserialize for a modeled error (exception)
      */
     private fun generateExceptionDeserializer(ctx: ProtocolGenerator.GenerationContext, shape: StructureShape) {
-        val outputSymbol = ctx.symbolProvider.toSymbol(shape)
+        val deserializationSymbol = ctx.symbolProvider.toSymbol(shape)
         val exceptionDeserializerSymbols = setOf(
             RuntimeTypes.Core.ExecutionContext,
             RuntimeTypes.Http.Response.HttpResponse,
@@ -611,11 +765,11 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         )
 
         val deserializerSymbol = buildSymbol {
-            val deserializerName = "${outputSymbol.name}Deserializer"
+            val deserializerName = "${deserializationSymbol.name}Deserializer"
             definitionFile = "$deserializerName.kt"
             name = deserializerName
             namespace = ctx.settings.pkg.serde
-            reference(outputSymbol, SymbolReference.ContextOption.DECLARE)
+            reference(deserializationSymbol, SymbolReference.ContextOption.DECLARE)
         }
 
         // exception deserializers are never streaming
@@ -623,23 +777,25 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
 
         ctx.delegator.useSymbolWriter(deserializerSymbol) { writer ->
             val resolver = getProtocolHttpBindingResolver(ctx.model, ctx.service)
-            val responseBindings = resolver.responseBindings(shape)
+            val bindings = if (ctx.settings.build.generateServiceProject) {
+                resolver.requestBindings(shape)
+            } else {
+                resolver.responseBindings(shape)
+            }
             writer
                 .addImport(exceptionDeserializerSymbols)
                 .write("")
-                .openBlock("internal class #T: #T.NonStreaming<#T> {", deserializerSymbol, RuntimeTypes.HttpClient.Operation.HttpDeserializer, outputSymbol)
+                .openBlock("internal class #T: #T.NonStreaming<#T> {", deserializerSymbol, RuntimeTypes.HttpClient.Operation.HttpDeserializer, deserializationSymbol)
                 .write("")
-                .call {
-                    renderHttpDeserialize(ctx, outputSymbol, responseBindings, serdeMeta, null, writer)
-                }
+                .call { renderHttpDeserialize(ctx, deserializationSymbol, bindings, serdeMeta, null, writer) }
                 .closeBlock("}")
         }
     }
 
     private fun renderHttpDeserialize(
         ctx: ProtocolGenerator.GenerationContext,
-        outputSymbol: Symbol,
-        responseBindings: List<HttpBindingDescriptor>,
+        deserializationSymbol: Symbol,
+        bindings: List<HttpBindingDescriptor>,
         serdeMeta: HttpSerdeMeta,
         // this method is shared between operation and exception deserialization. In the case of operations this MUST be set
         op: OperationShape?,
@@ -651,7 +807,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     "override suspend fun deserialize(context: #T, call: #T): #T {",
                     RuntimeTypes.Core.ExecutionContext,
                     RuntimeTypes.Http.HttpCall,
-                    outputSymbol,
+                    deserializationSymbol,
                 )
         } else {
             writer
@@ -660,22 +816,22 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     RuntimeTypes.Core.ExecutionContext,
                     RuntimeTypes.Http.HttpCall,
                     KotlinTypes.ByteArray,
-                    outputSymbol,
+                    deserializationSymbol,
                 )
         }
 
         writer.write("val response = call.response")
             .call {
-                if (outputSymbol.shape?.isError == false && op != null) {
+                if (deserializationSymbol.shape?.isError == false && op != null) {
                     // handle operation errors
                     renderIsHttpError(ctx, op, writer)
                 }
             }
-            .write("val builder = #T.Builder()", outputSymbol)
+            .write("val builder = #T.Builder()", deserializationSymbol)
             .write("")
             .call {
                 // headers
-                val headerBindings = responseBindings
+                val headerBindings = bindings
                     .filter { it.location == HttpBinding.Location.HEADER }
                     .sortedBy { it.memberName }
 
@@ -683,7 +839,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
 
                 // prefix headers
                 // spec: "Only a single structure member can be bound to httpPrefixHeaders"
-                responseBindings.firstOrNull { it.location == HttpBinding.Location.PREFIX_HEADERS }
+                bindings.firstOrNull { it.location == HttpBinding.Location.PREFIX_HEADERS }
                     ?.let {
                         renderDeserializePrefixHeaders(ctx, it, writer)
                     }
@@ -693,11 +849,70 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                 if (op != null && op.isOutputEventStream(ctx.model)) {
                     deserializeViaEventStream(ctx, op, writer)
                 } else {
-                    deserializeViaPayload(ctx, outputSymbol, responseBindings, serdeMeta, op, writer)
+                    deserializeViaPayload(ctx, deserializationSymbol, bindings, serdeMeta, op, writer)
                 }
             }
             .call {
-                responseBindings.firstOrNull { it.location == HttpBinding.Location.RESPONSE_CODE }
+                bindings.firstOrNull { it.location == HttpBinding.Location.RESPONSE_CODE }
+                    ?.let {
+                        renderDeserializeResponseCode(ctx, it, writer)
+                    }
+            }
+            // Render client side error correction for `@required` members.
+            // NOTE: nested members bound via the document/payload will be handled by the deserializer for the relevant
+            // content type. All other members (e.g. bound via REST semantics) will be corrected here.
+            .write("builder.correctErrors()")
+            .write("return builder.build()")
+            .closeBlock("}")
+    }
+
+    private fun renderServiceHttpDeserialize(
+        ctx: ProtocolGenerator.GenerationContext,
+        deserializationSymbol: Symbol,
+        bindings: List<HttpBindingDescriptor>,
+        serdeMeta: HttpSerdeMeta,
+        // this method is shared between operation and exception deserialization. In the case of operations this MUST be set
+        op: OperationShape?,
+        writer: KotlinWriter,
+    ) {
+        writer
+            .openBlock(
+                "public fun deserialize(context: #T, call: #T, payload: #T?): #T {",
+                RuntimeTypes.Core.ExecutionContext,
+                RuntimeTypes.KtorServerCore.ApplicationCallClass,
+                KotlinTypes.ByteArray,
+                deserializationSymbol,
+            )
+
+        writer.write("val request = call.request")
+            .write("val builder = #T.Builder()", deserializationSymbol)
+            .write("")
+            .call {
+                // headers
+                val headerBindings = bindings
+                    .filter { it.location == HttpBinding.Location.HEADER }
+                    .sortedBy { it.memberName }
+
+                renderDeserializeHeaders(ctx, headerBindings, writer)
+
+                // prefix headers
+                // spec: "Only a single structure member can be bound to httpPrefixHeaders"
+                bindings.firstOrNull { it.location == HttpBinding.Location.PREFIX_HEADERS }
+                    ?.let {
+                        renderDeserializePrefixHeaders(ctx, it, writer)
+                    }
+            }
+            .write("")
+            .call {
+                // TODO: will never enter this block. event stream is not in the scope of service generation for now.
+                if (op != null && op.isOutputEventStream(ctx.model)) {
+                    deserializeViaEventStream(ctx, op, writer)
+                } else {
+                    deserializeViaPayload(ctx, deserializationSymbol, bindings, serdeMeta, op, writer)
+                }
+            }
+            .call {
+                bindings.firstOrNull { it.location == HttpBinding.Location.RESPONSE_CODE }
                     ?.let {
                         renderDeserializeResponseCode(ctx, it, writer)
                     }
@@ -715,20 +930,20 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
      */
     private fun deserializeViaPayload(
         ctx: ProtocolGenerator.GenerationContext,
-        outputSymbol: Symbol,
-        responseBindings: List<HttpBindingDescriptor>,
+        deserializationSymbol: Symbol,
+        bindings: List<HttpBindingDescriptor>,
         serdeMeta: HttpSerdeMeta,
         // this method is shared between operation and exception deserialization. In the case of operations this MUST be set
         op: OperationShape?,
         writer: KotlinWriter,
     ) {
         // payload member(s)
-        val httpPayload = responseBindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
+        val httpPayload = bindings.firstOrNull { it.location == HttpBinding.Location.PAYLOAD }
         if (httpPayload != null) {
             renderExplicitHttpPayloadDeserializer(ctx, httpPayload, writer)
         } else {
             // Unbound document members that should be deserialized from the document format for the protocol.
-            val documentMembers = responseBindings
+            val documentMembers = bindings
                 .filter { it.location == HttpBinding.Location.DOCUMENT }
                 .sortedBy { it.memberName }
                 .map { it.member }
@@ -741,7 +956,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     sdg.operationDeserializer(ctx, op, documentMembers)
                 } else {
                     // error
-                    sdg.errorDeserializer(ctx, outputSymbol.shape as StructureShape, documentMembers)
+                    sdg.errorDeserializer(ctx, deserializationSymbol.shape as StructureShape, documentMembers)
                 }
 
                 if (!serdeMeta.isStreaming) {
@@ -770,7 +985,6 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         val memberTarget = ctx.model.expectShape(binding.member.target)
 
         check(memberTarget.type == ShapeType.INTEGER) { "Unexpected target type in response code deserialization: ${memberTarget.id} (${memberTarget.type})" }
-
         writer.write("builder.#L = response.status.value", memberName)
     }
 
@@ -794,21 +1008,25 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             } else {
                 ""
             }
-
+            val message = if (ctx.settings.build.generateServiceProject) {
+                "request"
+            } else {
+                "response"
+            }
             when (memberTarget) {
                 is NumberShape -> {
                     if (memberTarget is IntEnumShape) {
                         val enumSymbol = ctx.symbolProvider.toSymbol(memberTarget)
                         writer.addImport(enumSymbol)
                         writer.write(
-                            "builder.#L = response.headers[#S]?.let { #T.fromValue(it.toInt()) }",
+                            "builder.#L = $message.headers[#S]?.let { #T.fromValue(it.toInt()) }",
                             memberName,
                             headerName,
                             enumSymbol,
                         )
                     } else {
                         writer.write(
-                            "builder.#L = response.headers[#S]?.#L$defaultValuePostfix",
+                            "builder.#L = $message.headers[#S]?.#L$defaultValuePostfix",
                             memberName,
                             headerName,
                             stringToNumber(memberTarget),
@@ -817,13 +1035,13 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                 }
                 is BooleanShape -> {
                     writer.write(
-                        "builder.#L = response.headers[#S]?.toBoolean()$defaultValuePostfix",
+                        "builder.#L = $message.headers[#S]?.toBoolean()$defaultValuePostfix",
                         memberName,
                         headerName,
                     )
                 }
                 is BlobShape -> {
-                    writer.write("builder.#L = response.headers[#S]?.#T()", memberName, headerName, RuntimeTypes.Core.Text.Encoding.decodeBase64)
+                    writer.write("builder.#L = $message.headers[#S]?.#T()", memberName, headerName, RuntimeTypes.Core.Text.Encoding.decodeBase64)
                 }
                 is StringShape -> {
                     when {
@@ -831,17 +1049,17 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                             val enumSymbol = ctx.symbolProvider.toSymbol(memberTarget)
                             writer.addImport(enumSymbol)
                             writer.write(
-                                "builder.#L = response.headers[#S]?.let { #T.fromValue(it) }",
+                                "builder.#L = $message.headers[#S]?.let { #T.fromValue(it) }",
                                 memberName,
                                 headerName,
                                 enumSymbol,
                             )
                         }
                         memberTarget.hasTrait<MediaTypeTrait>() -> {
-                            writer.write("builder.#L = response.headers[#S]?.#T()", memberName, headerName, RuntimeTypes.Core.Text.Encoding.decodeBase64)
+                            writer.write("builder.#L = $message.headers[#S]?.#T()", memberName, headerName, RuntimeTypes.Core.Text.Encoding.decodeBase64)
                         }
                         else -> {
-                            writer.write("builder.#L = response.headers[#S]", memberName, headerName)
+                            writer.write("builder.#L = $message.headers[#S]", memberName, headerName)
                         }
                     }
                 }
@@ -852,7 +1070,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                         defaultTimestampFormat,
                     )
                     writer.write(
-                        "builder.#L = response.headers[#S]?.let { #L }",
+                        "builder.#L = $message.headers[#S]?.let { #L }",
                         memberName,
                         headerName,
                         writer.parseInstantExpr("it", tsFormat),
@@ -912,7 +1130,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
 
                     writer
                         .addImport(splitFn, KotlinDependency.HTTP, subpackage = "util")
-                        .write("builder.#L = response.headers.getAll(#S)?.flatMap(::$splitFn)$mapFn", memberName, headerName)
+                        .write("builder.#L = $message.headers.getAll(#S)?.flatMap(::$splitFn)$mapFn", memberName, headerName)
                 }
                 else -> throw CodegenException("unknown deserialization: header binding: $hdrBinding; member: `$memberName`")
             }
@@ -941,7 +1159,12 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             ""
         }
 
-        writer.write("val $keyCollName = response.headers.names()$filter")
+        val message = if (ctx.settings.build.generateServiceProject) {
+            "request"
+        } else {
+            "response"
+        }
+        writer.write("val $keyCollName = $message.headers.names()$filter")
         writer.openBlock("if ($keyCollName.isNotEmpty()) {")
             .write("val map = mutableMapOf<String, #T>()", targetValueSymbol)
             .openBlock("for (hdrKey in $keyCollName) {")
@@ -952,7 +1175,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
                     else -> throw CodegenException("invalid httpPrefixHeaders usage on ${binding.member}")
                 }
                 // get()/getAll() returns String? or List<String>?, this shouldn't ever trigger the continue though...
-                writer.write("val el = response.headers$getFn ?: continue")
+                writer.write("val el = $message.headers$getFn ?: continue")
                 if (prefix?.isNotEmpty() == true) {
                     writer.write("val key = hdrKey.removePrefix(#S)", prefix)
                     writer.write("map[key] = el")
@@ -977,7 +1200,11 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
         val memberName = binding.member.defaultName()
         val target = ctx.model.expectShape(binding.member.target)
         val targetSymbol = ctx.symbolProvider.toSymbol(target)
-
+        val message = if (ctx.settings.build.generateServiceProject) {
+            "request"
+        } else {
+            "response"
+        }
         // NOTE: we don't need serde metadata to know what to do here. Everything is non-streaming except streaming
         // blob payloads.
         when (target.type) {
@@ -1003,7 +1230,7 @@ abstract class HttpBindingProtocolGenerator : ProtocolGenerator {
             ShapeType.BLOB -> {
                 val isBinaryStream = target.hasTrait<StreamingTrait>()
                 if (isBinaryStream) {
-                    writer.write("builder.#L = response.body.#T()", memberName, RuntimeTypes.Http.toByteStream)
+                    writer.write("builder.#L = $message.body.#T()", memberName, RuntimeTypes.Http.toByteStream)
                 } else {
                     writer.write("builder.#L = payload", memberName)
                 }
@@ -1107,8 +1334,25 @@ private data class HttpSerdeMeta(val isStreaming: Boolean) {
 }
 
 private fun httpDeserializerInfo(ctx: ProtocolGenerator.GenerationContext, op: OperationShape): HttpSerdeMeta {
-    val isStreaming = ctx.model.expectShape<StructureShape>(op.output.get()).hasStreamingMember(ctx.model) ||
+    val deserializationTarget = if (ctx.settings.build.generateServiceProject) {
+        op.input
+    } else {
+        op.output
+    }
+    val isStreaming = ctx.model.expectShape<StructureShape>(deserializationTarget.get()).hasStreamingMember(ctx.model) ||
         op.isOutputEventStream(ctx.model)
 
     return HttpSerdeMeta(isStreaming)
 }
+
+private fun getHttpSerializerResultSymbol(protocolName: String) = when (protocolName) {
+    "smithyRpcv2cbor" -> KotlinTypes.ByteArray
+    "awsRestjson1" -> KotlinTypes.String
+    else -> error("service project accepts only Cbor or JSON protocol")
+}
+
+private fun getHttpSerializerDefaultResponse(protocolName: String) = when (protocolName) {
+    "smithyRpcv2cbor" -> "ByteArray(0)"
+    "awsRestjson1" -> "\"\""
+    else -> error("service project accepts only Cbor or JSON protocol")
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingResolver.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingResolver.kt
index f6cfad41b9..7e2345f836 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingResolver.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpBindingResolver.kt
@@ -53,10 +53,10 @@ interface HttpBindingResolver {
 
     /**
      * Return request bindings for an operation.
-     * @param operationShape [OperationShape] for which to retrieve bindings
+     * @param shape [Shape] for which to retrieve bindings
      * @return all found http request bindings
      */
-    fun requestBindings(operationShape: OperationShape): List<HttpBindingDescriptor>
+    fun requestBindings(shape: Shape): List<HttpBindingDescriptor>
 
     /**
      * Return response bindings for an operation.
@@ -90,11 +90,19 @@ interface HttpBindingResolver {
 /**
  * @return true if the operation contains request data bound to the PAYLOAD or DOCUMENT locations
  */
-fun HttpBindingResolver.hasHttpBody(operationShape: OperationShape): Boolean =
+fun HttpBindingResolver.hasHttpRequestBody(operationShape: OperationShape): Boolean =
     requestBindings(operationShape).any {
         it.location == HttpBinding.Location.PAYLOAD || it.location == HttpBinding.Location.DOCUMENT
     }
 
+/**
+ * @return true if the operation contains request data bound to the PAYLOAD or DOCUMENT locations
+ */
+fun HttpBindingResolver.hasHttpResponseBody(operationShape: OperationShape): Boolean =
+    responseBindings(operationShape).any {
+        it.location == HttpBinding.Location.PAYLOAD || it.location == HttpBinding.Location.DOCUMENT
+    }
+
 /**
  * Protocol content type mappings
  */
@@ -141,10 +149,12 @@ class HttpTraitResolver(
 
     override fun httpTrait(operationShape: OperationShape): HttpTrait = operationShape.expectTrait()
 
-    override fun requestBindings(operationShape: OperationShape): List<HttpBindingDescriptor> = bindingIndex
-        .getRequestBindings(operationShape)
-        .values
-        .map { HttpBindingDescriptor(it) }
+    override fun requestBindings(shape: Shape): List<HttpBindingDescriptor> = when (shape) {
+        is OperationShape,
+        is StructureShape,
+        -> bindingIndex.getRequestBindings(shape.toShapeId()).values.map { HttpBindingDescriptor(it) }
+        else -> error { "Unimplemented resolving bindings for ${shape.javaClass.canonicalName}" }
+    }
 
     override fun responseBindings(shape: Shape): List<HttpBindingDescriptor> = when (shape) {
         is OperationShape,
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborParserGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborParserGenerator.kt
index ac0518edd7..ba2fb9105e 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborParserGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborParserGenerator.kt
@@ -24,12 +24,17 @@ class CborParserGenerator(
         op: OperationShape,
         members: List<MemberShape>,
     ): Symbol {
-        val outputSymbol = ctx.symbolProvider.toSymbol(ctx.model.expectShape(op.outputShape))
+        val deserializationShape = if (ctx.settings.build.generateServiceProject) {
+            op.inputShape
+        } else {
+            op.outputShape
+        }
+        val deserializationsymbol = ctx.symbolProvider.toSymbol(ctx.model.expectShape(deserializationShape))
 
         return op.bodyDeserializer(ctx.settings) { writer ->
             addNestedDocumentDeserializers(ctx, op, writer)
             val fnName = op.bodyDeserializerName()
-            writer.withBlock("private fun #L(builder: #T.Builder, payload: ByteArray) {", "}", fnName, outputSymbol) {
+            writer.withBlock("private fun #L(builder: #T.Builder, payload: ByteArray) {", "}", fnName, deserializationsymbol) {
                 call { renderDeserializeOperationBody(ctx, op, members, writer) }
             }
         }
@@ -91,9 +96,13 @@ class CborParserGenerator(
         writer: KotlinWriter,
     ) {
         writer.write("val deserializer = #T(payload)", RuntimeTypes.Serde.SerdeCbor.CborDeserializer)
-
-        val shape = ctx.model.expectShape(op.output.get())
-        renderDeserializerBody(ctx, shape, documentMembers, writer)
+        val deserializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.input
+        } else {
+            op.output
+        }
+        val deserializationShape = ctx.model.expectShape(deserializationTarget.get())
+        renderDeserializerBody(ctx, deserializationShape, documentMembers, writer)
     }
 
     private fun renderDeserializerBody(
@@ -103,7 +112,6 @@ class CborParserGenerator(
         writer: KotlinWriter,
     ) {
         descriptorGenerator(ctx, shape, members, writer).render()
-
         if (shape.isUnionShape) {
             val name = ctx.symbolProvider.toSymbol(shape).name
             DeserializeUnionGenerator(ctx, name, members, writer, TimestampFormatTrait.Format.EPOCH_SECONDS).render()
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborSerializerGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborSerializerGenerator.kt
index 545a484a90..a4467e10e3 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborSerializerGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/CborSerializerGenerator.kt
@@ -9,6 +9,7 @@ import software.amazon.smithy.codegen.core.SymbolReference
 import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
 import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
 import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
 import software.amazon.smithy.kotlin.codegen.model.knowledge.SerdeIndex
 import software.amazon.smithy.kotlin.codegen.model.targetOrSelf
 import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
@@ -20,12 +21,28 @@ class CborSerializerGenerator(
     private val protocolGenerator: ProtocolGenerator,
 ) : StructuredDataSerializerGenerator {
     override fun operationSerializer(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, members: List<MemberShape>): Symbol {
-        val input = op.input.get().let { ctx.model.expectShape(it) }
-        val symbol = ctx.symbolProvider.toSymbol(input)
+        val serializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.output
+        } else {
+            op.input
+        }
+        val serializationShape = serializationTarget.get().let { ctx.model.expectShape(it) }
+        val serializationSymbol = ctx.symbolProvider.toSymbol(serializationShape)
 
+        val serializerResultSymbol = when {
+            ctx.settings.build.generateServiceProject -> KotlinTypes.ByteArray
+            else -> RuntimeTypes.Http.HttpBody
+        }
         return op.bodySerializer(ctx.settings) { writer ->
             addNestedDocumentSerializers(ctx, op, writer)
-            writer.withBlock("private fun #L(context: #T, input: #T): #T {", "}", op.bodySerializerName(), RuntimeTypes.Core.ExecutionContext, symbol, RuntimeTypes.Http.HttpBody) {
+            writer.withBlock(
+                "private fun #L(context: #T, input: #T): #T {",
+                "}",
+                op.bodySerializerName(),
+                RuntimeTypes.Core.ExecutionContext,
+                serializationSymbol,
+                serializerResultSymbol,
+            ) {
                 call {
                     renderSerializeOperationBody(ctx, op, members, writer)
                 }
@@ -39,10 +56,19 @@ class CborSerializerGenerator(
         documentMembers: List<MemberShape>,
         writer: KotlinWriter,
     ) {
-        val shape = ctx.model.expectShape(op.input.get())
+        val serializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.output
+        } else {
+            op.input
+        }
+        val serializationshape = ctx.model.expectShape(serializationTarget.get())
         writer.write("val serializer = #T()", RuntimeTypes.Serde.SerdeCbor.CborSerializer)
-        renderSerializerBody(ctx, shape, documentMembers, writer)
-        writer.write("return serializer.toHttpBody()")
+        renderSerializerBody(ctx, serializationshape, documentMembers, writer)
+        if (ctx.settings.build.generateServiceProject) {
+            writer.write("return serializer.toByteArray()")
+        } else {
+            writer.write("return serializer.toHttpBody()")
+        }
     }
 
     private fun renderSerializerBody(
@@ -112,4 +138,24 @@ class CborSerializerGenerator(
             }
         }
     }
+
+    override fun errorSerializer(
+        ctx: ProtocolGenerator.GenerationContext,
+        errorShape: StructureShape,
+        members: List<MemberShape>,
+    ): Symbol {
+        val symbol = ctx.symbolProvider.toSymbol(errorShape)
+
+        return symbol.errorSerializer(ctx.settings) { writer ->
+            addNestedDocumentSerializers(ctx, errorShape, writer)
+            val fnName = symbol.errorSerializerName()
+            writer.openBlock("private fun #L(context: #T, input: #T): ByteArray {", fnName, RuntimeTypes.Core.ExecutionContext, symbol)
+                .write("val serializer = #T()", RuntimeTypes.Serde.SerdeCbor.CborSerializer)
+                .call {
+                    renderSerializerBody(ctx, errorShape, members, writer)
+                }
+                .write("return serializer.toByteArray()")
+                .closeBlock("}")
+        }
+    }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonParserGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonParserGenerator.kt
index 4970e55f91..a98bb369e6 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonParserGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonParserGenerator.kt
@@ -36,7 +36,12 @@ open class JsonParserGenerator(
     )
 
     override fun operationDeserializer(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, members: List<MemberShape>): Symbol {
-        val outputSymbol = op.output.get().let { ctx.symbolProvider.toSymbol(ctx.model.expectShape(it)) }
+        val deserializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.input
+        } else {
+            op.output
+        }
+        val outputSymbol = deserializationTarget.get().let { ctx.symbolProvider.toSymbol(ctx.model.expectShape(it)) }
         return op.bodyDeserializer(ctx.settings) { writer ->
             addNestedDocumentDeserializers(ctx, op, writer)
             val fnName = op.bodyDeserializerName()
@@ -74,8 +79,13 @@ open class JsonParserGenerator(
         documentMembers: List<MemberShape>,
         writer: KotlinWriter,
     ) {
+        val deserializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.input
+        } else {
+            op.output
+        }
         writer.write("val deserializer = #T(payload)", RuntimeTypes.Serde.SerdeJson.JsonDeserializer)
-        val shape = ctx.model.expectShape(op.output.get())
+        val shape = ctx.model.expectShape(deserializationTarget.get())
         renderDeserializerBody(ctx, shape, documentMembers, writer)
     }
 
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonSerializerGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonSerializerGenerator.kt
index 6366fe8e04..62a78064b3 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonSerializerGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/JsonSerializerGenerator.kt
@@ -26,8 +26,13 @@ open class JsonSerializerGenerator(
     open val defaultTimestampFormat: TimestampFormatTrait.Format = TimestampFormatTrait.Format.EPOCH_SECONDS
 
     override fun operationSerializer(ctx: ProtocolGenerator.GenerationContext, op: OperationShape, members: List<MemberShape>): Symbol {
-        val input = ctx.model.expectShape(op.input.get())
-        val symbol = ctx.symbolProvider.toSymbol(input)
+        val serializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.output
+        } else {
+            op.input
+        }
+        val shape = ctx.model.expectShape(serializationTarget.get())
+        val symbol = ctx.symbolProvider.toSymbol(shape)
 
         return op.bodySerializer(ctx.settings) { writer ->
             addNestedDocumentSerializers(ctx, op, writer)
@@ -61,7 +66,12 @@ open class JsonSerializerGenerator(
         documentMembers: List<MemberShape>,
         writer: KotlinWriter,
     ) {
-        val shape = ctx.model.expectShape(op.input.get())
+        val serializationTarget = if (ctx.settings.build.generateServiceProject) {
+            op.output
+        } else {
+            op.input
+        }
+        val shape = ctx.model.expectShape(serializationTarget.get())
         writer.write("val serializer = #T()", RuntimeTypes.Serde.SerdeJson.JsonSerializer)
         renderSerializerBody(ctx, shape, documentMembers, writer)
         writer.write("return serializer.toByteArray()")
@@ -118,4 +128,24 @@ open class JsonSerializerGenerator(
             }
         }
     }
+
+    override fun errorSerializer(
+        ctx: ProtocolGenerator.GenerationContext,
+        errorShape: StructureShape,
+        members: List<MemberShape>,
+    ): Symbol {
+        val symbol = ctx.symbolProvider.toSymbol(errorShape)
+
+        return symbol.errorSerializer(ctx.settings) { writer ->
+            addNestedDocumentSerializers(ctx, errorShape, writer)
+            val fnName = symbol.errorSerializerName()
+            writer.openBlock("private fun #L(context: #T, input: #T): String {", fnName, RuntimeTypes.Core.ExecutionContext, symbol)
+                .write("val serializer = #T()", RuntimeTypes.Serde.SerdeJson.JsonSerializer)
+                .call {
+                    renderSerializerBody(ctx, errorShape, members, writer)
+                }
+                .write("return serializer.toByteArray().decodeToString()")
+                .closeBlock("}")
+        }
+    }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerdeExt.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerdeExt.kt
index 071d8ba364..2083b83524 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerdeExt.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerdeExt.kt
@@ -149,6 +149,26 @@ fun Symbol.errorDeserializer(settings: KotlinSettings, block: SymbolRenderer): S
     renderBy = block
 }
 
+/**
+ * Get the serializer name for an error shape
+ */
+fun Symbol.errorSerializerName(): String = "serialize" + StringUtils.capitalize(this.name) + "Error"
+
+/**
+ * Get the function responsible for serializing members bound to the payload of an error shape as [Symbol] and
+ * register [block] * which will be invoked to actually render the function (signature and implementation)
+ */
+fun Symbol.errorSerializer(settings: KotlinSettings, block: SymbolRenderer): Symbol = buildSymbol {
+    name = errorSerializerName()
+    namespace = settings.pkg.serde
+    val symbol = this@errorSerializer
+    // place it in the same file as the exception deserializer, e.g. for HTTP protocols this will be in
+    // same file as HttpDeserialize
+    definitionFile = "${symbol.name}Serializer.kt"
+    reference(symbol, SymbolReference.ContextOption.DECLARE)
+    renderBy = block
+}
+
 /**
  * Get the function responsible for deserializing the specific shape as a standalone payload
  */
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/StructuredDataSerializerGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/StructuredDataSerializerGenerator.kt
index c3e49c128d..7d08a03b86 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/StructuredDataSerializerGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/StructuredDataSerializerGenerator.kt
@@ -10,6 +10,7 @@ import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerato
 import software.amazon.smithy.model.shapes.MemberShape
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.Shape
+import software.amazon.smithy.model.shapes.StructureShape
 
 /**
  * Responsible for rendering serialization of structured data (e.g. json, yaml, xml).
@@ -56,4 +57,27 @@ interface StructuredDataSerializerGenerator {
         shape: Shape,
         members: Collection<MemberShape>? = null,
     ): Symbol
+
+    /**
+     * Render function responsible for serializing members bound to the payload for the given error shape.
+     *
+     * Because only a subset of fields of an operation error may be bound to the payload a builder is given
+     * as an argument.
+     *
+     * ```
+     * fun serializeFooError(builder: FooError.Builder, payload: ByteArray) {
+     *     ...
+     * }
+     * ```
+     *
+     * Implementations are expected to instantiate an appropriate serializer for the protocol and serialize
+     * the error shape from the payload using the builder passed in.
+     *
+     * @param ctx the protocol generator context
+     * @param errorShape the error shape to render deserialize for
+     * @param members the members of the error shape that are bound to the payload. Not all members are
+     * bound to the document, some may be bound to e.g. headers, status code, etc
+     * @return the generated symbol which should be a function matching the signature expected for the protocol
+     */
+    fun errorSerializer(ctx: ProtocolGenerator.GenerationContext, errorShape: StructureShape, members: List<MemberShape>): Symbol
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/XmlSerializerGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/XmlSerializerGenerator.kt
index 1f77136e15..0ff77e2e85 100644
--- a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/XmlSerializerGenerator.kt
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/XmlSerializerGenerator.kt
@@ -18,6 +18,7 @@ import software.amazon.smithy.kotlin.codegen.rendering.protocol.toRenderingConte
 import software.amazon.smithy.model.shapes.MemberShape
 import software.amazon.smithy.model.shapes.OperationShape
 import software.amazon.smithy.model.shapes.Shape
+import software.amazon.smithy.model.shapes.StructureShape
 import software.amazon.smithy.model.shapes.UnionShape
 import software.amazon.smithy.model.traits.TimestampFormatTrait
 import software.amazon.smithy.model.traits.XmlAttributeTrait
@@ -141,4 +142,12 @@ open class XmlSerializerGenerator(
             }
         }
     }
+
+    override fun errorSerializer(
+        ctx: ProtocolGenerator.GenerationContext,
+        errorShape: StructureShape,
+        members: List<MemberShape>,
+    ): Symbol {
+        TODO("Used for service-codegen. Not yet implemented")
+    }
 }
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/README.md b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/README.md
new file mode 100644
index 0000000000..18832f7e6a
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/README.md
@@ -0,0 +1,43 @@
+# Smithy Kotlin Service Codegen (SKSC)
+
+## Overview
+
+This project generate **service-side code** from Smithy models, producing **complete service stubs**, including routing, serialization/deserialization, authentication, and validation, so developers can focus entirely on implementing business logic.
+
+While Ktor is the default backend, the architecture is framework-agnostic, allowing future support for other server frameworks.
+
+
+## Getting Started
+
+- Get an [introduction to Smithy](https://smithy.io/2.0/index.html)
+- Follow [Smithy's quickstart guide](https://smithy.io/2.0/quickstart.html)
+- See the [Guide](docs/GettingStarted.md) to learn how to use SKSC to generate service.
+- See a [Summary of Service Support](docs/FEATURES.md) to learn which features are supported
+
+
+## Development
+
+### Module Structure
+
+- `constraints` – directory that contains the constraints validation generator.
+  - `ConstraintsGenerator.kt` - main generator for constraints.
+  - `ConstraintUtilsGenerator` - generator for constraint utilities.
+  - For each constraint trait, there is a dedicated file.
+- `ktor` – directory that stores all features generators specific to Ktor.
+  - `ktorStubGenerator.kt` – main generator for ktor framework service stub generator.
+- `ServiceStubConfiguration.kt` – configuration file for the service stub generator.
+- `ServiceStubGenerator.kt` – abstract service stub generator file.
+- `ServiceTypes.kt` – file that includes service component symbols.
+- `utils.kt` – utilities file.
+
+### Testing
+
+The **service code generation tests** are located in `tests/codegen/service-codegen-tests`. These end-to-end tests generate the service, launch the server, send HTTP requests to validate functionality, and then shut down the service once testing is complete. This process typically takes around 2 minutes. To run tests specifically for SKSC, use the following command:
+```bash
+  ./gradlew :tests:codegen:service-codegen-tests:test
+```
+
+## Feedback
+
+You can provide feedback or report a bug by submitting an [issue](https://github.com/smithy-lang/smithy-kotlin/issues/new/choose).
+This is the preferred mechanism to give feedback so that other users can engage in the conversation, +1 issues, etc.
\ No newline at end of file
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubConfigurations.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubConfigurations.kt
new file mode 100644
index 0000000000..012f557174
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubConfigurations.kt
@@ -0,0 +1,98 @@
+package software.amazon.smithy.kotlin.codegen.service
+
+import software.amazon.smithy.aws.traits.protocols.RestJson1Trait
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
+import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
+import software.amazon.smithy.kotlin.codegen.service.ktor.KtorStubGenerator
+import software.amazon.smithy.model.shapes.ServiceShape
+import software.amazon.smithy.model.shapes.ShapeId
+import software.amazon.smithy.model.shapes.ShapeType
+import software.amazon.smithy.model.traits.HttpPayloadTrait
+import software.amazon.smithy.model.traits.MediaTypeTrait
+import software.amazon.smithy.protocol.traits.Rpcv2CborTrait
+
+/**
+ * Enumeration of supported media types used by the generated service.
+ *
+ * These values define how payloads are encoded/decoded:
+ * - `CBOR`         → Concise Binary Object Representation
+ * - `JSON`         → JSON encoding
+ * - `PLAIN_TEXT`   → Text/plain
+ * - `OCTET_STREAM` → Binary data
+ * - `ANY`          → Fallback for arbitrary content types
+ */
+enum class MediaType(val value: String) {
+    CBOR("CBOR"),
+    JSON("JSON"),
+    PLAIN_TEXT("PLAIN_TEXT"),
+    OCTET_STREAM("OctetStream"),
+    ANY("ANY"),
+    ;
+
+    override fun toString(): String = value
+
+    companion object {
+        fun fromValue(value: String): MediaType = MediaType
+            .entries
+            .firstOrNull { it.name.equals(value.uppercase(), ignoreCase = true) }
+            ?: throw IllegalArgumentException("$value is not a validContentType value, expected one of ${MediaType.entries}")
+
+        fun fromServiceShape(ctx: GenerationContext, shape: ServiceShape, targetShapeId: ShapeId): MediaType {
+            return when {
+                shape.hasTrait(Rpcv2CborTrait.ID) -> CBOR
+                shape.hasTrait(RestJson1Trait.ID) -> {
+                    val targetShape = ctx.model.expectShape(targetShapeId)
+                    for (memberShape in targetShape.allMembers.values) {
+                        if (!memberShape.hasTrait(HttpPayloadTrait.ID)) continue
+                        val memberType = ctx.model.expectShape(memberShape.target).type
+                        when (memberType) {
+                            ShapeType.STRING -> return PLAIN_TEXT
+                            ShapeType.BLOB -> return OCTET_STREAM
+                            ShapeType.DOCUMENT,
+                            ShapeType.STRUCTURE,
+                            ShapeType.UNION,
+                            -> return JSON
+                            else -> {
+                                if (memberShape.hasTrait(MediaTypeTrait.ID)) return ANY
+                            }
+                        }
+                    }
+                    return JSON
+                }
+
+                else -> throw IllegalArgumentException("Cannot find supported MediaType for the service")
+            }
+        }
+    }
+}
+
+/**
+ * Enumeration of supported service frameworks for generated stubs.
+ *
+ * Currently only supports:
+ * - `KTOR`: Generates Ktor-based service stubs
+ */
+enum class ServiceFramework(val value: String) {
+    KTOR("ktor"),
+    ;
+
+    override fun toString(): String = value
+
+    companion object {
+        fun fromValue(value: String): ServiceFramework = when (value.lowercase()) {
+            "ktor" -> KTOR
+            else -> throw IllegalArgumentException("$value is not a valid ServerFramework value, expected $KTOR")
+        }
+    }
+
+    internal fun getServiceFrameworkGenerator(
+        ctx: GenerationContext,
+        delegator: KotlinDelegator,
+        fileManifest: FileManifest,
+    ): AbstractStubGenerator {
+        when (this) {
+            KTOR -> return KtorStubGenerator(ctx, delegator, fileManifest)
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubGenerator.kt
new file mode 100644
index 0000000000..ef3a46a7be
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubGenerator.kt
@@ -0,0 +1,271 @@
+package software.amazon.smithy.kotlin.codegen.service
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
+import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.defaultName
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.core.withInlineBlock
+import software.amazon.smithy.model.knowledge.TopDownIndex
+
+/**
+ * Interface representing a generator that produces service stubs (boilerplate code) for a Smithy service.
+ */
+internal interface ServiceStubGenerator {
+    /**
+     * Render the stub code into the target files.
+     */
+    fun render()
+}
+
+/**
+ * Abstract base class for generating service stubs.
+ *
+ * Provides a framework for generating common service artifacts such as:
+ * - Configuration (`ServiceFrameworkConfig.kt`)
+ * - Framework bootstrap (`ServiceFramework.kt`)
+ * - Plugins, utils, authentication, validators
+ * - Operation handlers and routing
+ * - Main launcher (`Main.kt`)
+ *
+ * Concrete subclasses must implement abstract methods for framework-specific
+ * code (e.g., Ktor).
+ */
+internal abstract class AbstractStubGenerator(
+    val ctx: GenerationContext,
+    val delegator: KotlinDelegator,
+    val fileManifest: FileManifest,
+) : ServiceStubGenerator {
+
+    val serviceShape = ctx.settings.getService(ctx.model)
+    val operations = TopDownIndex.of(ctx.model)
+        .getContainedOperations(serviceShape)
+        .sortedBy { it.defaultName() }
+
+    val pkgName = ctx.settings.pkg.name
+
+    /**
+     * Render all service stub files by invoking the component renderers.
+     * This acts as the main entrypoint for code generation.
+     */
+    final override fun render() {
+        renderServiceFrameworkConfig()
+        renderServiceFramework()
+        renderPlugins()
+        renderUtils()
+        renderAuthModule()
+        renderConstraintValidators()
+        renderPerOperationHandlers()
+        renderRouting()
+        renderMainFile()
+    }
+
+    /**
+     * Generate the service configuration file (`ServiceFrameworkConfig.kt`).
+     *
+     * Defines enums for:
+     * - `LogLevel`: Logging verbosity levels
+     * - `ServiceEngine`: Available server engines (Netty, CIO, Jetty)
+     *
+     * Provides a singleton `ServiceFrameworkConfig` object that stores runtime
+     * settings such as port, engine, region, timeouts, and log level.
+     */
+    protected fun renderServiceFrameworkConfig() {
+        delegator.useFileWriter("ServiceFrameworkConfig.kt", "${ctx.settings.pkg.name}.config") { writer ->
+            writer.withBlock("internal enum class LogLevel(val value: String) {", "}") {
+                write("INFO(#S),", "INFO")
+                write("WARN(#S),", "WARN")
+                write("DEBUG(#S),", "DEBUG")
+                write("ERROR(#S),", "ERROR")
+                write("TRACE(#S),", "TRACE")
+                write("OFF(#S),", "OFF")
+                write(";")
+                write("")
+                write("override fun toString(): String = value")
+                write("")
+                withBlock("companion object {", "}") {
+                    withBlock("fun fromValue(value: String): #T = when (value.uppercase()) {", "}", ServiceTypes(pkgName).logLevel) {
+                        write("INFO.value -> INFO")
+                        write("WARN.value -> WARN")
+                        write("DEBUG.value -> DEBUG")
+                        write("ERROR.value -> ERROR")
+                        write("TRACE.value -> TRACE")
+                        write("OFF.value -> OFF")
+                        write("else -> throw IllegalArgumentException(#S)", "Unknown LogLevel value: \$value")
+                    }
+                }
+            }
+            writer.write("")
+
+            writer.withBlock("internal enum class ServiceEngine(val value: String) {", "}") {
+                write("NETTY_ENGINE(#S),", "netty")
+                write("CIO_ENGINE(#S),", "cio")
+                write("JETTY_JAKARTA_ENGINE(#S),", "jetty-jakarta")
+                write(";")
+                write("")
+                write("override fun toString(): String = value")
+                write("")
+                withBlock("companion object {", "}") {
+                    withBlock("fun fromValue(value: String): #T {", "}", ServiceTypes(pkgName).serviceEngine) {
+                        write(
+                            "return #T.entries.firstOrNull { it.value.equals(value.lowercase(), ignoreCase = true) } ?: throw IllegalArgumentException(#S)",
+                            ServiceTypes(pkgName).serviceEngine,
+                            "\$value is not a validContentType value, expected one of \${ServiceEngine.entries}",
+                        )
+                    }
+                }
+                write("")
+                withBlock("fun toEngineFactory(): #T<*, *> {", "}", RuntimeTypes.KtorServerCore.ApplicationEngineFactory) {
+                    withBlock("return when(this) {", "}") {
+                        write("NETTY_ENGINE -> #T as #T<*, *>", RuntimeTypes.KtorServerNetty.Netty, RuntimeTypes.KtorServerCore.ApplicationEngineFactory)
+                        write("CIO_ENGINE -> #T as #T<*, *>", RuntimeTypes.KtorServerCio.CIO, RuntimeTypes.KtorServerCore.ApplicationEngineFactory)
+                        write("JETTY_JAKARTA_ENGINE -> #T as #T<*, *>", RuntimeTypes.KtorServerJettyJakarta.Jetty, RuntimeTypes.KtorServerCore.ApplicationEngineFactory)
+                    }
+                }
+            }
+            writer.write("")
+
+            writer.withBlock("internal object ServiceFrameworkConfig {", "}") {
+                write("private var backing: Data? = null")
+                write("")
+                withBlock("private data class Data(", ")") {
+                    write("val port: Int,")
+                    write("val engine: #T,", ServiceTypes(pkgName).serviceEngine)
+                    write("val region: String,")
+                    write("val requestBodyLimit: Long,")
+                    write("val requestReadTimeoutSeconds: Int,")
+                    write("val responseWriteTimeoutSeconds: Int,")
+                    write("val closeGracePeriodMillis: Long,")
+                    write("val closeTimeoutMillis: Long,")
+                    write("val logLevel: #T,", ServiceTypes(pkgName).logLevel)
+                }
+                write("")
+                write("val port: Int get() = backing?.port ?: notInitialised(#S)", "port")
+                write("val engine: #T get() = backing?.engine ?: notInitialised(#S)", ServiceTypes(pkgName).serviceEngine, "engine")
+                write("val region: String get() = backing?.region ?: notInitialised(#S)", "region")
+                write("val requestBodyLimit: Long get() = backing?.requestBodyLimit ?: notInitialised(#S)", "requestBodyLimit")
+                write("val requestReadTimeoutSeconds: Int get() = backing?.requestReadTimeoutSeconds ?: notInitialised(#S)", "requestReadTimeoutSeconds")
+                write("val responseWriteTimeoutSeconds: Int get() = backing?.responseWriteTimeoutSeconds ?: notInitialised(#S)", "responseWriteTimeoutSeconds")
+                write("val closeGracePeriodMillis: Long get() = backing?.closeGracePeriodMillis ?: notInitialised(#S)", "closeGracePeriodMillis")
+                write("val closeTimeoutMillis: Long get() = backing?.closeTimeoutMillis ?: notInitialised(#S)", "closeTimeoutMillis")
+                write("val logLevel: #T get() = backing?.logLevel ?: notInitialised(#S)", ServiceTypes(pkgName).logLevel, "logLevel")
+                write("")
+                withInlineBlock("fun init(", ")") {
+                    write("port: Int,")
+                    write("engine: #T,", ServiceTypes(pkgName).serviceEngine)
+                    write("region: String,")
+                    write("requestBodyLimit: Long,")
+                    write("requestReadTimeoutSeconds: Int,")
+                    write("responseWriteTimeoutSeconds: Int,")
+                    write("closeGracePeriodMillis: Long,")
+                    write("closeTimeoutMillis: Long,")
+                    write("logLevel: #T,", ServiceTypes(pkgName).logLevel)
+                }
+                withBlock("{", "}") {
+                    write("check(backing == null) { #S }", "ServiceFrameworkConfig has already been initialised")
+                    write("backing = Data(port, engine, region, requestBodyLimit, requestReadTimeoutSeconds, responseWriteTimeoutSeconds, closeGracePeriodMillis, closeTimeoutMillis, logLevel)")
+                }
+                write("")
+                withBlock("private fun notInitialised(prop: String): Nothing {", "}") {
+                    write("error(#S)", "ServiceFrameworkConfig.\$prop accessed before init()")
+                }
+            }
+        }
+    }
+
+    /**
+     * Generate the service framework interface and bootstrap (`ServiceFramework.kt`).
+     *
+     * Declares a common `ServiceFramework` interface with lifecycle methods and
+     * delegates framework-specific implementation details to subclasses.
+     */
+    protected fun renderServiceFramework() {
+        delegator.useFileWriter("ServiceFramework.kt", "${ctx.settings.pkg.name}.framework") { writer ->
+
+            writer.withBlock("internal interface ServiceFramework: #T {", "}", RuntimeTypes.Core.IO.Closeable) {
+                write("// start the service and begin accepting connections")
+                write("public fun start()")
+            }
+                .write("")
+
+            renderServerFrameworkImplementation(writer)
+        }
+    }
+
+    /** Render the specific server framework implementation (e.g., Ktor). */
+    protected abstract fun renderServerFrameworkImplementation(writer: KotlinWriter)
+
+    /** Generate service plugins such as content-type guards, error handlers, etc. */
+    protected abstract fun renderPlugins()
+
+    /** Generate supporting utility classes and functions. */
+    protected abstract fun renderUtils()
+
+    /** Generate authentication module interfaces and installers (e.g., bearer auth, SigV4, SigV4A). */
+    protected abstract fun renderAuthModule()
+
+    /** Generate request-level constraint validators for Smithy model constraints. */
+    protected abstract fun renderConstraintValidators()
+
+    /** Generate a request handler for each Smithy operation. */
+    protected abstract fun renderPerOperationHandlers()
+
+    /** Generate the route table that maps Smithy operations to runtime endpoints. */
+    protected abstract fun renderRouting()
+
+    /**
+     * Generate the top-level `Main.kt` launcher file.
+     *
+     * This file provides the `main()` entrypoint:
+     * - Parses command-line arguments
+     * - Applies defaults for configuration values
+     * - Initializes the `ServiceFrameworkConfig`
+     * - Starts the appropriate service framework
+     */
+    protected fun renderMainFile() {
+        val portName = "port"
+        val engineFactoryName = "engineFactory"
+        val regionName = "region"
+        val requestBodyLimitName = "requestBodyLimit"
+        val requestReadTimeoutSecondsName = "requestReadTimeoutSeconds"
+        val responseWriteTimeoutSecondsName = "responseWriteTimeoutSeconds"
+        val closeGracePeriodMillisName = "closeGracePeriodMillis"
+        val closeTimeoutMillisName = "closeTimeoutMillis"
+        val logLevelName = "logLevel"
+        delegator.useFileWriter("Main.kt", ctx.settings.pkg.name) { writer ->
+
+            writer.withBlock("public fun main(args: Array<String>): Unit {", "}") {
+                write("val argMap: Map<String, String> = args.asList().chunked(2).associate { (k, v) -> k.removePrefix(#S) to v }", "--")
+                write("")
+                write("val defaultPort = 8080")
+                write("val defaultEngine = #T.NETTY_ENGINE.value", ServiceTypes(pkgName).serviceEngine)
+                write("val defaultRegion = #S", "us-east-1")
+                write("val defaultRequestBodyLimit = 10L * 1024 * 1024")
+                write("val defaultRequestReadTimeoutSeconds = 30")
+                write("val defaultResponseWriteTimeoutSeconds = 30")
+                write("val defaultCloseGracePeriodMillis = 1_000L")
+                write("val defaultCloseTimeoutMillis = 5_000L")
+                write("val defaultLogLevel = #T.INFO.value", ServiceTypes(pkgName).logLevel)
+                write("")
+                withBlock("#T.init(", ")", ServiceTypes(pkgName).serviceFrameworkConfig) {
+                    write("port = argMap[#S]?.toInt() ?: defaultPort, ", portName)
+                    write("engine = #T.fromValue(argMap[#S] ?: defaultEngine), ", ServiceTypes(pkgName).serviceEngine, engineFactoryName)
+                    write("region = argMap[#S]?.toString() ?: defaultRegion, ", regionName)
+                    write("requestBodyLimit = argMap[#S]?.toLong() ?: defaultRequestBodyLimit, ", requestBodyLimitName)
+                    write("requestReadTimeoutSeconds = argMap[#S]?.toInt() ?: defaultRequestReadTimeoutSeconds, ", requestReadTimeoutSecondsName)
+                    write("responseWriteTimeoutSeconds = argMap[#S]?.toInt() ?: defaultResponseWriteTimeoutSeconds, ", responseWriteTimeoutSecondsName)
+                    write("closeGracePeriodMillis = argMap[#S]?.toLong() ?: defaultCloseGracePeriodMillis, ", closeGracePeriodMillisName)
+                    write("closeTimeoutMillis = argMap[#S]?.toLong() ?: defaultCloseTimeoutMillis, ", closeTimeoutMillisName)
+                    write("logLevel = #T.fromValue(argMap[#S] ?: defaultLogLevel), ", ServiceTypes(pkgName).logLevel, logLevelName)
+                }
+                write("")
+                when (ctx.settings.serviceStub.framework) {
+                    ServiceFramework.KTOR -> write("val service = #T()", ServiceTypes(pkgName).ktorServiceFramework)
+                }
+                write("service.start()")
+            }
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceTypes.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceTypes.kt
new file mode 100644
index 0000000000..74385533cf
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceTypes.kt
@@ -0,0 +1,85 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.smithy.kotlin.codegen.service
+
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+
+class ServiceTypes(val pkgName: String) {
+    val logLevel = buildSymbol {
+        name = "LogLevel"
+        namespace = "$pkgName.config"
+    }
+
+    val serviceEngine = buildSymbol {
+        name = "ServiceEngine"
+        namespace = "$pkgName.config"
+    }
+
+    val serviceFrameworkConfig = buildSymbol {
+        name = "ServiceFrameworkConfig"
+        namespace = "$pkgName.config"
+    }
+
+    val ktorServiceFramework = buildSymbol {
+        name = "KtorServiceFramework"
+        namespace = "$pkgName.framework"
+    }
+
+    val module = buildSymbol {
+        name = "module"
+        namespace = "$pkgName.framework"
+    }
+
+    val configureErrorHandling = buildSymbol {
+        name = "configureErrorHandling"
+        namespace = "$pkgName.plugins"
+    }
+
+    val configureRouting = buildSymbol {
+        name = "configureRouting"
+        namespace = pkgName
+    }
+
+    val configureLogging = buildSymbol {
+        name = "configureLogging"
+        namespace = "$pkgName.utils"
+    }
+
+    val configureAuthentication = buildSymbol {
+        name = "configureAuthentication"
+        namespace = "$pkgName.auth"
+    }
+
+    val errorEnvelope = buildSymbol {
+        name = "ErrorEnvelope"
+        namespace = "$pkgName.plugins"
+    }
+
+    val contentTypeGuard = buildSymbol {
+        name = "ContentTypeGuard"
+        namespace = "$pkgName.plugins"
+    }
+
+    val acceptTypeGuard = buildSymbol {
+        name = "AcceptTypeGuard"
+        namespace = "$pkgName.plugins"
+    }
+
+    val sizeOf = buildSymbol {
+        name = "sizeOf"
+        namespace = "$pkgName.constraints"
+    }
+
+    val hasAllUniqueElements = buildSymbol {
+        name = "hasAllUniqueElements"
+        namespace = "$pkgName.constraints"
+    }
+
+    val responseHandledKey = buildSymbol {
+        name = "ResponseHandledKey"
+        namespace = "$pkgName.plugins"
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/AbstractConstraintTraitGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/AbstractConstraintTraitGenerator.kt
new file mode 100644
index 0000000000..fc9c0319c0
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/AbstractConstraintTraitGenerator.kt
@@ -0,0 +1,5 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+internal abstract class AbstractConstraintTraitGenerator {
+    abstract fun render()
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintGenerator.kt
new file mode 100644
index 0000000000..cde979575d
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintGenerator.kt
@@ -0,0 +1,104 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
+import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.model.shapes.MemberShape
+import software.amazon.smithy.model.shapes.OperationShape
+import software.amazon.smithy.model.shapes.StructureShape
+import software.amazon.smithy.model.traits.RequiredTrait
+import kotlin.collections.iterator
+
+/**
+ * Generates validation code for request constraints on Smithy operation inputs.
+ *
+ * For a given [operation], this generator traverses the input structure and:
+ * - Recursively inspects members of structures and lists.
+ * - Applies trait-based validations (e.g., required, length, range).
+ * - Generates Kotlin validation functions that check constraints at runtime.
+ *
+ * Output is written into a `<Operation>RequestConstraints.kt` file in the generated `constraints` package.
+ */
+internal class ConstraintGenerator(
+    val ctx: GenerationContext,
+    val operation: OperationShape,
+    val delegator: KotlinDelegator,
+) {
+    val inputShape = ctx.model.expectShape(operation.input.get()) as StructureShape
+    val inputMembers = inputShape.allMembers
+
+    val opName = operation.id.name
+    val pkgName = ctx.settings.pkg.name
+
+    /**
+     * Entry point for emitting validation code for the operation’s request type.
+     * Delegates to [renderRequestConstraintsValidation].
+     */
+    fun render() {
+        renderRequestConstraintsValidation()
+    }
+
+    /**
+     * Recursively generates validation code for a given [memberShape].
+     *
+     * - If the target is a list, iterates over elements and validates them.
+     * - If the target is a structure, recursively validates its members.
+     * - For each trait (on the member or its target), invokes the matching trait generator.
+     *   - `@required` traits are always enforced.
+     *   - Other traits are wrapped in a null check before validation.
+     */
+    private fun generateConstraintValidations(prefix: String, memberShape: MemberShape, writer: KotlinWriter) {
+        val targetShape = ctx.model.expectShape(memberShape.target)
+
+        val memberName = memberShape.memberName
+        val memberAndTargetTraits = memberShape.allTraits + targetShape.allTraits
+        when {
+            targetShape.isListShape ->
+                for (member in targetShape.allMembers) {
+                    val newMemberPrefix = "${targetShape.id.name}".replaceFirstChar { it.lowercase() }
+                    writer.withBlock("if ($prefix$memberName != null) {", "}") {
+                        withBlock("for ($newMemberPrefix${member.key} in $prefix$memberName ?: listOf()) {", "}") {
+                            call { generateConstraintValidations(newMemberPrefix, member.value, writer) }
+                        }
+                    }
+                }
+            targetShape.isStructureShape ->
+                for (member in targetShape.allMembers) {
+                    val newMemberPrefix = "$prefix$memberName?."
+                    generateConstraintValidations(newMemberPrefix, member.value, writer)
+                }
+        }
+        for (memberTrait in memberAndTargetTraits.values) {
+            val traitGenerator = getTraitGeneratorFromTrait(prefix, memberName, memberTrait, pkgName, writer)
+            traitGenerator?.apply {
+                if (memberTrait !is RequiredTrait) {
+                    writer.withBlock("if ($prefix$memberName != null) {", "}") {
+                        render()
+                    }
+                } else {
+                    render()
+                }
+            }
+        }
+    }
+
+    /**
+     * Writes the top-level validation function for the operation’s input type.
+     *
+     * Inside, it calls [generateConstraintValidations] for each input member,
+     * ensuring all modeled constraints are enforced.
+     */
+    private fun renderRequestConstraintsValidation() {
+        delegator.useFileWriter("${opName}RequestConstraints.kt", "$pkgName.constraints") { writer ->
+            val inputShape = ctx.model.expectShape(operation.input.get())
+            val inputSymbol = ctx.symbolProvider.toSymbol(inputShape)
+
+            writer.withBlock("public fun check${opName}RequestConstraint(data: #T) {", "}", inputSymbol) {
+                for (memberShape in inputMembers.values) {
+                    generateConstraintValidations("data.", memberShape, writer)
+                }
+            }
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintUtilsGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintUtilsGenerator.kt
new file mode 100644
index 0000000000..b93f690287
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/ConstraintUtilsGenerator.kt
@@ -0,0 +1,104 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
+import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+
+/**
+ * Generates utility functions to support constraint validation for Smithy models.
+ *
+ * This generator emits reusable helpers that can be called from operation-specific
+ * validation code (e.g., generated by [ConstraintGenerator]). These helpers enforce
+ * common traits like `@length` and `@uniqueItems`.
+ *
+ * Output is written into a `utils.kt` file under the generated `constraints` package.
+ */
+internal class ConstraintUtilsGenerator(
+    val ctx: GenerationContext,
+    val delegator: KotlinDelegator,
+) {
+    val pkgName = ctx.settings.pkg.name
+
+    fun render() {
+        delegator.useFileWriter("utils.kt", "$pkgName.constraints") { writer ->
+            renderLengthTraitUtils(writer)
+
+            writer.write("")
+            renderUniqueItemsTraitUtils(writer)
+        }
+    }
+
+    /**
+     * Generates the `sizeOf()` function.
+     *
+     * This utility computes a generalized "size" for multiple types:
+     * - Collections, arrays, maps → `size`
+     * - Strings → Unicode code point count
+     * - Byte arrays → length
+     *
+     * Any unsupported type will throw an `IllegalArgumentException`.
+     */
+    private fun renderLengthTraitUtils(writer: KotlinWriter) {
+        writer.withBlock("internal fun sizeOf(value: Any?): Long = when (value) {", "}") {
+            write("is Collection<*> -> value.size.toLong()")
+            write("is Array<*> -> value.size.toLong()")
+            write("is Map<*, *> -> value.size.toLong()")
+            write("is String -> value.codePointCount(0, value.length).toLong()")
+            write("is ByteArray -> value.size.toLong()")
+            withBlock("else -> {", "}") {
+                write("val typeName = value?.javaClass?.simpleName ?: #S", "null")
+                write("throw IllegalArgumentException( #S )", "sizeOf does not support \${typeName} type")
+            }
+        }
+    }
+
+    /**
+     * Generates the `hasAllUniqueElements()` function.
+     *
+     * This utility checks if a list contains only unique elements, where uniqueness
+     * is defined by deep structural equality:
+     * - Primitive wrappers (String, Boolean, Number, Instant) → compared by value
+     * - Byte arrays → compared by contents
+     * - Lists → recursively compared element by element
+     * - Maps → recursively compared entries by key/value
+     */
+    private fun renderUniqueItemsTraitUtils(writer: KotlinWriter) {
+        writer.withBlock("internal fun hasAllUniqueElements(elements: List<Any?>): Boolean {", "}") {
+            withBlock("class Wrapped(private val v: Any?) {", "}") {
+                withBlock("override fun equals(other: Any?): Boolean {", "}") {
+                    write("if (other !is Wrapped) return false")
+                    write("if (v?.javaClass != other.v?.javaClass) return false")
+                    withBlock("return when (v) {", "}") {
+                        write("null -> true")
+                        write("is String,")
+                        write("is Boolean,")
+                        write("is java.time.Instant,")
+                        write("is Number -> v == other.v")
+                        write("is ByteArray -> v.contentEquals(other.v as ByteArray)")
+                        withBlock("is List<*> -> {", "}") {
+                            write("val o = other.v as List<*>")
+                            write("v.size == o.size &&  v.indices.all { i -> Wrapped(v[i]) == Wrapped(o[i]) }")
+                        }
+                        withBlock("is Map<*, *>  -> {", "}") {
+                            write("val o = other.v as Map<*, *>")
+                            write("v.size == o.size && v.all { (k, value) -> o.containsKey(k) && Wrapped(value) == Wrapped(o[k]) }")
+                        }
+                        write("else -> v == other.v")
+                    }
+                }
+                withBlock("override fun hashCode(): Int = when (v) {", "}") {
+                    write("null -> 0")
+                    write("is ByteArray -> v.contentHashCode()")
+                    write("is List<*> -> v.fold(1) { acc, e -> 31 * acc + Wrapped(e).hashCode() }")
+                    write("is Map<*, *> -> v.entries.fold(1) { acc, (k, e) -> 31 * acc + Wrapped(k).hashCode() xor Wrapped(e).hashCode() }")
+                    write("else -> v.hashCode()")
+                }
+            }
+            write("")
+            write("val seen = HashSet<Wrapped>(elements.size)")
+            write("for (e in elements) if (!seen.add(Wrapped(e))) return false")
+            write("return true")
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/LengthConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/LengthConstraintGenerator.kt
new file mode 100644
index 0000000000..04cef3ea9b
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/LengthConstraintGenerator.kt
@@ -0,0 +1,21 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+import software.amazon.smithy.model.traits.LengthTrait
+
+internal class LengthConstraintGenerator(val memberPrefix: String, val memberName: String, val trait: LengthTrait, val pkgName: String, val writer: KotlinWriter) : AbstractConstraintTraitGenerator() {
+    override fun render() {
+        val min = trait.min.orElse(null)
+        val max = trait.max.orElse(null)
+        val member = "$memberPrefix$memberName"
+
+        if (max != null && min != null) {
+            writer.write("require(#T($member) in $min..$max) { #S }", ServiceTypes(pkgName).sizeOf, "The size of `$memberName` must be between $min and $max (inclusive)")
+        } else if (max != null) {
+            writer.write("require(#T($member) <= $max) { #S }", ServiceTypes(pkgName).sizeOf, "The size of `$memberName` must be less than or equal to $max")
+        } else {
+            writer.write("require(#T($member) >= $min) { #S }", ServiceTypes(pkgName).sizeOf, "The size of `$memberName` must be greater than or equal to $min")
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/PatternConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/PatternConstraintGenerator.kt
new file mode 100644
index 0000000000..9c02278190
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/PatternConstraintGenerator.kt
@@ -0,0 +1,12 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.model.traits.PatternTrait
+
+internal class PatternConstraintGenerator(val memberPrefix: String, val memberName: String, val trait: PatternTrait, val pkgName: String, val writer: KotlinWriter) : AbstractConstraintTraitGenerator() {
+    override fun render() {
+        val member = "$memberPrefix$memberName"
+
+        writer.write("require(Regex(#S).containsMatchIn($member)) { #S }", trait.pattern.toString(), "Value `\${$member}` does not match required pattern: `${trait.pattern}`")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RangeConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RangeConstraintGenerator.kt
new file mode 100644
index 0000000000..9c2eeeb279
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RangeConstraintGenerator.kt
@@ -0,0 +1,20 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.model.traits.RangeTrait
+
+internal class RangeConstraintGenerator(val memberPrefix: String, val memberName: String, val trait: RangeTrait, val pkgName: String, val writer: KotlinWriter) : AbstractConstraintTraitGenerator() {
+    override fun render() {
+        val min = trait.min.orElse(null)
+        val max = trait.max.orElse(null)
+        val member = "$memberPrefix$memberName"
+
+        if (max != null && min != null) {
+            writer.write("require($member in $min..$max) { #S }", "`$memberName` must be between $min and $max (inclusive)")
+        } else if (max != null) {
+            writer.write("require($member <= $max) { #S }", "`$memberName` must be less than or equal to $max")
+        } else {
+            writer.write("require($member >= $min) { #S }", "`$memberName` must be greater than or equal to $min")
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RequiredConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RequiredConstraintGenerator.kt
new file mode 100644
index 0000000000..a0fc814a94
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/RequiredConstraintGenerator.kt
@@ -0,0 +1,11 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.model.traits.RequiredTrait
+
+internal class RequiredConstraintGenerator(val memberPrefix: String, val memberName: String, val trait: RequiredTrait, val pkgName: String, val writer: KotlinWriter) : AbstractConstraintTraitGenerator() {
+    override fun render() {
+        val member = "$memberPrefix$memberName"
+        writer.write("require($member != null) { #S }", "`$memberName` must be provided")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/UniqueItemsConstraintGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/UniqueItemsConstraintGenerator.kt
new file mode 100644
index 0000000000..644b2bc99c
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/UniqueItemsConstraintGenerator.kt
@@ -0,0 +1,12 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+import software.amazon.smithy.model.traits.UniqueItemsTrait
+
+internal class UniqueItemsConstraintGenerator(val memberPrefix: String, val memberName: String, val trait: UniqueItemsTrait, val pkgName: String, val writer: KotlinWriter) : AbstractConstraintTraitGenerator() {
+    override fun render() {
+        val member = "$memberPrefix$memberName"
+        writer.write("require(#T($member)) { #S }", ServiceTypes(pkgName).hasAllUniqueElements, "`$memberName` must contain only unique items, duplicate values are not allowed")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/utils.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/utils.kt
new file mode 100644
index 0000000000..82985ac9fa
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/constraints/utils.kt
@@ -0,0 +1,24 @@
+package software.amazon.smithy.kotlin.codegen.service.constraints
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.model.traits.LengthTrait
+import software.amazon.smithy.model.traits.PatternTrait
+import software.amazon.smithy.model.traits.RangeTrait
+import software.amazon.smithy.model.traits.RequiredTrait
+import software.amazon.smithy.model.traits.Trait
+import software.amazon.smithy.model.traits.UniqueItemsTrait
+
+internal fun getTraitGeneratorFromTrait(
+    memberPrefix: String,
+    memberName: String,
+    trait: Trait,
+    pkgName: String,
+    writer: KotlinWriter,
+): AbstractConstraintTraitGenerator? = when (trait) {
+    is LengthTrait -> LengthConstraintGenerator(memberPrefix, memberName, trait, pkgName, writer)
+    is PatternTrait -> PatternConstraintGenerator(memberPrefix, memberName, trait, pkgName, writer)
+    is RangeTrait -> RangeConstraintGenerator(memberPrefix, memberName, trait, pkgName, writer)
+    is UniqueItemsTrait -> UniqueItemsConstraintGenerator(memberPrefix, memberName, trait, pkgName, writer)
+    is RequiredTrait -> RequiredConstraintGenerator(memberPrefix, memberName, trait, pkgName, writer)
+    else -> null
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/FEATURES.md b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/FEATURES.md
new file mode 100644
index 0000000000..03784e96b6
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/FEATURES.md
@@ -0,0 +1,59 @@
+# Summary
+
+---
+
+### Features Support
+
+| **Features**                      | **Description**                                                                                 |
+|-----------------------------------|-------------------------------------------------------------------------------------------------|
+| Service Framework                 | Abstracted service framework interface and base implementation with Ktor as the default backend |
+| CBOR Protocol                     | Support for CBOR serialization / deserialization and CBOR protocol traits                       |
+| Json Protocol                     | Support for Json serialization / deserialization and Json protocol traits                       |
+| Routing                           | Per-operation routing generation with Ktor DSL; ties to handler and validation                  |
+| Error Handler                     | Unified exception handling logic mapped to HTTP status codes and support for error trait        |
+| Authentication (bearer)           | Bearer token authentication middleware with model-driven configuration                          |
+| Authentication (SigV4 and SigV4A) | SigV4 and SigV4A authentication middleware with model-driven configuration                      |
+| Logging                           | Structured logging setup                                                                        |
+| Constraints Checker               | Validation logic generated from Smithy traits and invoked pre-handler                           |
+| Unit Test                         | Covers serialization/deserialization, routing, validation, and integration tests                |
+
+### Smithy Protocol Traits Support
+
+| **Traits**               | **CBOR Protocol** | **Json Protocol** |
+|--------------------------|-------------------|-------------------|
+| http                     | Yes               | Yes               |
+| httpError                | Yes               | Yes               |
+| httpHeader               | Not supported     | Yes               |
+| httpPrefixHeader         | Not supported     | Yes               |
+| httpLabel                | Not supported     | Yes               |
+| httpQuery                | Not supported     | Yes               |
+| httpQueryParams          | Not supported     | Yes               |
+| httpPayload              | Not supported     | Yes               |
+| jsonName                 | Not supported     | Yes               |
+| timestampFormat          | Not supported     | Yes               |
+| httpChecksumRequired     | Not supported     | Not implemented yet |
+| requestCompression       | Not implemented yet | Not implemented yet |
+
+### Constraint Traits Support
+
+| **Traits**      | **CBOR Protocol**            | **Json Protocol**            |
+|-----------------|------------------------------|------------------------------|
+| required        | Yes                          | Yes                          |
+| length          | Yes                          | Yes                          |
+| pattern         | Yes                          | Yes                          |
+| private         | Yes (handled by Smithy)      | Yes (handled by Smithy)      |
+| range           | Yes                          | Yes                          |
+| uniqueItems     | Yes                          | Yes                          |
+| idRef           | Not implemented yet          | Not implemented yet          |
+
+
+### Future Features
+
+| Feature                           | Description                                                                                     |
+|-----------------------------------|-------------------------------------------------------------------------------------------------|
+| Additional Protocols              | XML, Ec2Query, AWSQuery protocols                                                               |
+| Middleware / Interceptors         | Cross-cutting logic support (e.g., metrics, headers, rate limiting) via middleware architecture |
+| API Versioning                    | Built-in support for versioned APIs to maintain backward compatibility                          |
+| gRPC / WebSocket Protocol Support | High-performance binary RPC and real-time bidirectional communication                           |
+| Metrics & Tracing                 | Observability support with metrics, logs, and distributed tracing for debugging and monitoring  |
+| Caching Middleware                | Per-route or global cache support to improve response times and reduce backend load             |
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/GettingStarted.md b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/GettingStarted.md
new file mode 100644
index 0000000000..73a7cdb348
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/docs/GettingStarted.md
@@ -0,0 +1,181 @@
+# Getting Started
+
+### Step 1: Build & Publish Codegen to Local Maven
+First, in **this repository**, build and publish the code generator locally:
+```bash
+  ./gradlew :codegen:smithy-kotlin-codegen:build
+  ./gradlew publishToMavenLocal
+```
+
+### Step 2: Create a New Kotlin Project
+Now, create a **new Kotlin project** where you will use the Smithy Kotlin service code generator. You can find a full example demo project [here](../../../../../../../../../../../../examples/service-codegen)
+
+From this point forward, **all steps apply to the new Kotlin project** you just created.
+
+
+### Step 3: Configure `build.gradle.kts` in the New Project
+
+```kotlin
+plugins {
+    alias(libs.plugins.kotlin.jvm)
+    id("software.amazon.smithy.gradle.smithy-jar") version "1.3.0" // check for latest version
+    application
+}
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+}
+
+val codegenVersion = "0.35.2-SNAPSHOT"
+val smithyVersion = "1.60.2"
+
+dependencies {
+    smithyBuild("software.amazon.smithy.kotlin:smithy-kotlin-codegen:$codegenVersion")
+    implementation("software.amazon.smithy.kotlin:smithy-aws-kotlin-codegen:$codegenVersion")
+    implementation("software.amazon.smithy:smithy-model:$smithyVersion")
+    implementation("software.amazon.smithy:smithy-build:$smithyVersion")
+    implementation("software.amazon.smithy:smithy-aws-traits:$smithyVersion")
+    ...
+}
+```
+
+
+### Step 4: Create `smithy-build.json` in the New Project
+This is an example of smithy-build.json.
+```json
+{
+    "version": "1.0",
+    "outputDirectory": "build/generated-src",
+    "plugins": {
+        "kotlin-codegen": {
+            "service": "com.demo#DemoService",
+            "package": {
+                "name": "com.demo.server",
+                "version": "1.0.0"
+            },
+            "build": {
+                "rootProject": true,
+                "generateServiceProject": true,
+                "optInAnnotations": [
+                    "aws.smithy.kotlin.runtime.InternalApi",
+                    "kotlinx.serialization.ExperimentalSerializationApi"
+                ]
+            },
+            "serviceStub": {
+              "framework": "ktor"
+            }
+        }
+    }
+}
+```
+
+**Notes:**
+- The most important fields are:
+    - **`outputDirectory`** — defines where the generated service code will be placed in your new project.
+    - **`service`** — must match your Smithy model’s `<namespace>#<service shape name>`.
+    - **`serviceStub.framework`** — defines the server framework for generated code. Currently only `"ktor"` is supported.
+
+### Step 5: Define Your Smithy Model in the New Project
+
+Create a `model` directory and add your `.smithy` files.  
+Example `model/greeter.smithy`:
+
+```smithy
+$version: "2.0"
+namespace com.demo
+
+use aws.protocols#restJson1
+use smithy.api#httpBearerAuth
+
+@restJson1
+@httpBearerAuth
+service DemoService {
+    version: "1.0.0"
+    operations: [
+        SayHello
+    ]
+}
+
+@http(method: "POST", uri: "/greet", code: 201)
+operation SayHello {
+    input: SayHelloInput
+    output: SayHelloOutput
+    errors: [
+        CustomError
+    ]
+}
+
+@input
+structure SayHelloInput {
+    @required
+    @length(min: 3, max: 10)
+    name: String
+    @httpHeader("X-User-ID")
+    id: Integer
+}
+
+@output
+structure SayHelloOutput {
+    greeting: String
+}
+
+@error("server")
+@httpError(500)
+structure CustomError {
+    msg: String
+    @httpHeader("X-User-error")
+    err: String
+}
+```
+
+### Step 6: Generate the Service in the New Project
+
+Run:
+```bash
+  gradle build
+```
+
+⚠️ Running gradle build will delete the previous build output before creating a new one.
+
+If you want to prevent accidentally losing previous build, use the provided scripts instead:
+
+You can find script for Linux / macOS [here](../../../../../../../../../../../../examples/service-codegen/build.sh):
+```bash
+  chmod +x build.sh
+  ./build.sh
+```
+
+You can find script for Windows [here](../../../../../../../../../../../../examples/service-codegen/build.bat):
+```bash
+  icacls build.bat /grant %USERNAME%:RX
+  .\build.bat
+```
+
+If you want to clean previously generated code:
+```bash
+  gradle clean
+```
+
+### Step 7: Run the Generated Service
+
+The generated service will be in the directory specified in `smithy-build.json` (`outputDirectory`).  
+You can start it by running:
+```bash
+  gradle run
+```
+By default, it listens on port **8080**.
+
+### Step 8: Adjust Service Configuration
+
+You can override runtime settings (such as port or HTTP engine) using command-line arguments:
+```bash
+  gradle run --args="port 8000 engineFactory cio"
+```
+You can find all available settings [here](https://github.com/smithy-lang/smithy-kotlin/blob/16bd523e2ccd6177dcc662466107189b013a818d/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ServiceStubGenerator.kt#L179C1-L186C38)
+
+---
+
+## Notes
+- **Business Logic**: Implement your own logic in the generated operation handler interfaces.
+- **Configuration**: Adjust port, engine, auth, and other settings via `ServiceFrameworkConfig` or CLI args.
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Authentication.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Authentication.kt
new file mode 100644
index 0000000000..5cac41a4b1
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Authentication.kt
@@ -0,0 +1,68 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.aws.traits.auth.SigV4ATrait
+import software.amazon.smithy.aws.traits.auth.SigV4Trait
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.model.getTrait
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+
+/**
+ * Writes Ktor-based authentication support classes and configuration
+ * for a generated service.
+ *
+ * This generates three files:
+ * 1. UserPrincipal.kt → Represents the authenticated user.
+ * 2. Validation.kt → Provides bearer token validation logic.
+ * 3. Authentication.kt → Configures authentication providers in Ktor.
+ */
+internal fun KtorStubGenerator.writeAuthentication() {
+    delegator.useFileWriter("UserPrincipal.kt", "$pkgName.auth") { writer ->
+        writer.withBlock("public data class UserPrincipal(", ")") {
+            write("val user: String")
+        }
+    }
+
+    delegator.useFileWriter("Validation.kt", "$pkgName.auth") { writer ->
+
+        writer.withBlock("internal object BearerValidation {", "}") {
+            withBlock("public fun bearerValidation(token: String): UserPrincipal? {", "}") {
+                write("// TODO: implement me:")
+                write("//  Validate the provided bearer token and return a UserPrincipal if valid.")
+                write("//  Return a UserPrincipal with user information (e.g., user id, roles) if valid,")
+                write("//  or return null if the token is invalid or expired.")
+                write("if (true) return UserPrincipal(#S) else return null", "Authenticated User")
+            }
+        }
+    }
+
+    delegator.useFileWriter("Authentication.kt", "$pkgName.auth") { writer ->
+        writer.withBlock("internal fun #T.configureAuthentication() {", "}", RuntimeTypes.KtorServerCore.Application) {
+            write("")
+            withBlock(
+                "#T(#T) {",
+                "}",
+                RuntimeTypes.KtorServerCore.install,
+                RuntimeTypes.KtorServerAuth.Authentication,
+            ) {
+                withBlock("#T(#S) {", "}", RuntimeTypes.KtorServerAuth.bearer, "auth-bearer") {
+                    write("realm = #S", "Access to API")
+                    write("authenticate { cred -> BearerValidation.bearerValidation(cred.token) }")
+                }
+                withBlock("sigV4(name = #S) {", "}", "aws-sigv4") {
+                    write("region = #T.region", ServiceTypes(pkgName).serviceFrameworkConfig)
+                    serviceShape.getTrait<SigV4Trait>()?.let {
+                        write("service = #S", it.name)
+                    }
+                }
+                withBlock("sigV4A(name = #S) {", "}", "aws-sigv4a") {
+                    write("region = #T.region", ServiceTypes(pkgName).serviceFrameworkConfig)
+                    serviceShape.getTrait<SigV4ATrait>()?.let {
+                        write("service = #S", it.name)
+                    }
+                }
+                write("provider(#S) { authenticate { ctx -> ctx.principal(Unit) } }", "no-auth")
+            }
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/AuthenticationAWS.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/AuthenticationAWS.kt
new file mode 100644
index 0000000000..e174f19c6b
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/AuthenticationAWS.kt
@@ -0,0 +1,493 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.closeAndOpenBlock
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.core.withInlineBlock
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
+
+/**
+ * Writes AWS-specific authentication support for Ktor service stubs.
+ *
+ * This generates the following files:
+ * - AWSValidation.kt → Stub stores for SigV4 credentials and SigV4A public keys.
+ * - AWSSigV4.kt → Ktor authentication provider and verifier for AWS Signature V4 (HMAC).
+ * - AWSSigV4A.kt → Ktor authentication provider and verifier for AWS Signature V4A (ECDSA).
+ */
+internal fun KtorStubGenerator.writeAWSAuthentication() {
+    delegator.useFileWriter("AWSValidation.kt", "$pkgName.auth") { writer ->
+        writer.withBlock("internal object SigV4CredentialStore {", "}") {
+            write("private val table: Map<String, #T> = mapOf()", RuntimeTypes.Auth.Credentials.AwsCredentials.Credentials)
+            withBlock("internal fun get(accessKeyId: String): #T? {", "}", RuntimeTypes.Auth.Credentials.AwsCredentials.Credentials) {
+                write("// TODO: implement me:")
+                write("//  Look up the credentials associated with this accessKeyId.")
+                write("//  Return a Credentials object like this:")
+                write("//    Credentials(")
+                write("//        accessKeyId = #S,", "<AWS_ACCESS_KEY_ID>")
+                write("//        secretAccessKey = #S,", "<AWS_SECRET_ACCESS_KEY>")
+                write("//        sessionToken = #S,", "<OPTIONAL_SESSION_TOKEN_IF_ANY>")
+                write("//    )")
+                write("return table[accessKeyId]")
+            }
+        }
+        writer.write("")
+        writer.withBlock("internal object SigV4aPublicKeyStore {", "}") {
+            write("private val table: Map<String, java.security.PublicKey> = mapOf()")
+            write("")
+            withBlock("internal fun get(accessKeyId: String): java.security.PublicKey? {", "}") {
+                write("// TODO: implement me:")
+                write("//  Look up the public key associated with this accessKeyId.")
+                write("//  Example if loading from bytes:")
+                write("//    val spec = X509EncodedKeySpec(keyBytes)")
+                write("//    val kf = KeyFactory.getInstance(\"EC\")")
+                write("//    return kf.generatePublic(spec)")
+                write("//  Return the java.security.PublicKey that should be used to verify SigV4A ECDSA signatures.")
+                write("return table[accessKeyId]")
+            }
+        }
+    }
+
+    delegator.useFileWriter("AWSSigV4.kt", "$pkgName.auth") { writer ->
+        writer.withInlineBlock("internal fun #T.sigV4(", ")", RuntimeTypes.KtorServerAuth.AuthenticationConfig) {
+            write("name: String = #S,", "aws-sigv4")
+            write("configure: SigV4AuthProvider.Configuration.() -> Unit = {}")
+        }
+            .withBlock("{", "}") {
+                write("val provider = SigV4AuthProvider(SigV4AuthProvider.Configuration(name).apply(configure))")
+                write("register(provider)")
+            }
+            .write("")
+
+        writer.withBlock("internal class SigV4AuthProvider(config: Configuration) : #T(config) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationProvider) {
+            withBlock("internal class Configuration(name: String?) : #T.Config(name) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationProvider) {
+                write("var region: String = #S", "us-east-1")
+                write("var service: String = #S", "execute-api")
+                write("var clockSkew: #T = 5.#T", KotlinTypes.Time.Duration, KotlinTypes.Time.minutes)
+            }
+            write("")
+            write("private val region = (config as Configuration).region")
+            write("private val service = config.service")
+            write("private val skew = config.clockSkew")
+            write("")
+            withBlock("override suspend fun onAuthenticate(context: #T) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationContext) {
+                write("val creds = verifySigV4(context.call, region, service, skew)")
+                withInlineBlock("if (creds == null) {", "}") {
+                    withBlock("context.challenge(#S, #T.InvalidCredentials) { challenge, call ->", "}", "AWS4-HMAC-SHA256", RuntimeTypes.KtorServerAuth.AuthenticationFailedCause) {
+                        write("call.#T(#T.Unauthorized, #S)", RuntimeTypes.KtorServerRouting.responseResponse, RuntimeTypes.KtorServerHttp.HttpStatusCode, "Unauthorized")
+                        write("challenge.complete()")
+                    }
+                }
+                withBlock(" else {", "}") {
+                    write("context.principal(UserPrincipal(creds.accessKeyId))")
+                }
+            }
+        }
+            .write("")
+
+        writer.withInlineBlock("public suspend fun verifySigV4(", ")") {
+            write("call: #T,", RuntimeTypes.KtorServerCore.ApplicationCallClass)
+            write("region: String,")
+            write("service: String,")
+            write("maxClockSkew: #T", KotlinTypes.Time.Duration)
+        }
+            .withBlock(": #T? {", "}", RuntimeTypes.Auth.Credentials.AwsCredentials.Credentials) {
+                retrieveAuthInformation(writer, "AWS4-HMAC-SHA256")
+                write("")
+                write("val scope = credential.substringAfter(#S, missingDelimiterValue = #S)", "/", "")
+                write("val parts = scope.split(#S)", "/")
+                write("if (parts.size != 4) return null")
+                write("val (yyyyMMdd, scopeRegion, scopeService, term) = parts")
+                write("if (scopeRegion != region || scopeService != service || term != #S) return null", "aws4_request")
+                write("if (!Regex(#S).matches(yyyyMMdd)) return null", "^\\d{8}$")
+                write("")
+                authDateValidation(writer)
+                write("")
+                write("val creds = SigV4CredentialStore.get(accessKeyId) ?: return null")
+                write("")
+                write("val secTokenHeaderName = #S", "x-amz-security-token")
+                write("val secToken = call.request.headers[secTokenHeaderName]")
+                withBlock("if (creds.sessionToken != null) {", "}") {
+                    write("if (secToken == null || secToken != creds.sessionToken) return null")
+                    write("if (secTokenHeaderName !in signedHeaders) return null")
+                }
+                write("")
+                write("val contentSha256 = call.request.headers[#S]", "x-amz-content-sha256")
+                write("val isUnsigned = contentSha256 == #S", "UNSIGNED-PAYLOAD")
+                write("")
+                createHttpRequestBuilder(writer)
+                write("")
+                validateSigV4(writer)
+                write("")
+                write("return if (expectedSig == signatureHex) creds else null")
+            }
+    }
+
+    delegator.useFileWriter("AWSSigV4A.kt", "$pkgName.auth") { writer ->
+        writer.withInlineBlock("internal fun #T.sigV4A(", ")", RuntimeTypes.KtorServerAuth.AuthenticationConfig) {
+            write("name: String = #S,", "aws-sigv4a")
+            write("configure: SigV4AAuthProvider.Configuration.() -> Unit = {}")
+        }
+            .withBlock("{", "}") {
+                write("val provider = SigV4AAuthProvider(SigV4AAuthProvider.Configuration(name).apply(configure))")
+                write("register(provider)")
+            }
+            .write("")
+
+        writer.withBlock("internal class SigV4AAuthProvider(config: Configuration) : #T(config) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationProvider) {
+            withBlock("internal class Configuration(name: String?) : #T.Config(name) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationProvider) {
+                write("var region: String = #S", "us-east-1")
+                write("var service: String = #S", "execute-api")
+                write("var clockSkew: #T = 5.#T", KotlinTypes.Time.Duration, KotlinTypes.Time.minutes)
+            }
+            write("")
+            write("private val region = (config as Configuration).region")
+            write("private val service = config.service")
+            write("private val skew = config.clockSkew")
+            write("")
+            withBlock("override suspend fun onAuthenticate(context: #T) {", "}", RuntimeTypes.KtorServerAuth.AuthenticationContext) {
+                write("val creds = verifySigV4A(context.call, region, service, skew)")
+                withInlineBlock("if (creds == null) {", "}") {
+                    withBlock("context.challenge(#S, #T.InvalidCredentials) { challenge, call ->", "}", "AWS4-HMAC-SHA256", RuntimeTypes.KtorServerAuth.AuthenticationFailedCause) {
+                        write("call.#T(#T.Unauthorized, #S)", RuntimeTypes.KtorServerRouting.responseResponse, RuntimeTypes.KtorServerHttp.HttpStatusCode, "Unauthorized")
+                        write("challenge.complete()")
+                    }
+                }
+                withBlock(" else {", "}") {
+                    write("context.principal(UserPrincipal(creds.accessKeyId))")
+                }
+            }
+        }
+            .write("")
+
+        writer.withInlineBlock("public suspend fun verifySigV4A(", ")") {
+            write("call: #T,", RuntimeTypes.KtorServerCore.ApplicationCallClass)
+            write("region: String,")
+            write("service: String,")
+            write("maxClockSkew: #T", KotlinTypes.Time.Duration)
+        }
+            .withBlock(": #T? {", "}", RuntimeTypes.Auth.Credentials.AwsCredentials.Credentials) {
+                retrieveAuthInformation(writer, "AWS4-ECDSA-P256-SHA256")
+                write("")
+                write("val scope = credential.substringAfter(#S, missingDelimiterValue = #S)", "/", "")
+                write("val parts = scope.split(#S)", "/")
+                write("if (parts.size != 3) return null")
+                write("val (yyyyMMdd, scopeService, term) = parts")
+                write("if (scopeService != service || term != #S) return null", "aws4_request")
+                write("if (!Regex(#S).matches(yyyyMMdd)) return null", "^\\d{8}$")
+                write("")
+                write("val regionSetHeaderName = #S", "x-amz-region-set")
+                write("val rawRegionSet = call.request.headers[regionSetHeaderName] ?: return null")
+                write("if (regionSetHeaderName !in signedHeaders) return null")
+                write("")
+                write("val regionSet: List<String> = rawRegionSet.split(',').map { it.trim().lowercase() }.filter { it.isNotEmpty() }.ifEmpty { return null }")
+                write("")
+                withBlock("fun matchesRegion(pattern: String, value: String): Boolean {", "}") {
+                    write("if (pattern == #S) return true", "*")
+                    write("val normalized = pattern.trim().replace(Regex(#S), #S)", "\\*+", "*")
+                    write("val sb = StringBuilder(#S)", "^")
+                    write("val parts = normalized.split(#S)", "*")
+                    withBlock("parts.forEachIndexed { i, part ->", "}") {
+                        write("sb.append(Regex.escape(part))")
+                        write("if (i < parts.lastIndex) sb.append(#S)", "[^-]+")
+                    }
+                    write("sb.append(#S)", "$")
+                    write("return Regex(sb.toString(), RegexOption.IGNORE_CASE).matches(value.trim())")
+                }
+                write("if (regionSet.none { matchesRegion(it, region.lowercase()) }) return null")
+                write("")
+                authDateValidation(writer)
+                write("")
+                write("val creds = SigV4CredentialStore.get(accessKeyId) ?: return null")
+                write("")
+                write("val secTokenHeaderName = #S", "x-amz-security-token")
+                write("val secToken = call.request.headers[secTokenHeaderName]")
+                withBlock("if (creds.sessionToken != null) {", "}") {
+                    write("if (secToken == null || secToken != creds.sessionToken) return null")
+                    write("if (secTokenHeaderName !in signedHeaders) return null")
+                }
+                write("")
+                write("val contentSha256 = call.request.headers[#S]", "x-amz-content-sha256")
+                write("val isUnsigned = contentSha256 == #S", "UNSIGNED-PAYLOAD")
+                write("")
+                createCanonicalRequest(writer)
+                write("")
+                validateSigV4A(writer)
+                write("")
+                write("return if (ok) creds else null")
+            }
+            .write("")
+        renderHelperFunctions(writer)
+    }
+}
+
+/**
+ * Extracts and parses AWS authentication header information
+ * (Credential, SignedHeaders, Signature) from a request.
+ */
+private fun retrieveAuthInformation(writer: KotlinWriter, algorithm: String) {
+    writer.write("val authHeader = call.request.#T(#T.Authorization) ?: return null", RuntimeTypes.KtorServerRouting.requestHeader, RuntimeTypes.KtorServerHttp.HttpHeaders)
+        .write("if (!authHeader.startsWith(#S, ignoreCase = true)) return null", algorithm)
+        .write("")
+        .write("fun part(name: String) = authHeader.substringAfter(#S).substringBefore(#S).trim()", "\$name=", ",")
+        .write("")
+        .write("val credential = part(#S) // accessKeyId/scope", "Credential")
+        .write("val signedHeadersStr = part(#S)", "SignedHeaders")
+        .write("val signatureHex = part(#S)", "Signature")
+        .write("")
+        .write("val signedHeaders: Set<String> = signedHeadersStr.split(';').map { it.trim().lowercase() }.toSet()")
+        .write("if (#S !in signedHeaders) return null", "host")
+        .write("if (!signedHeaders.any { it == #S || it == #S }) return null", "x-amz-date", "date")
+        .write("val accessKeyId = credential.substringBefore(#S).takeIf { it.matches(Regex(#S)) } ?: return null", "/", "^[A-Z0-9]{16,128}$")
+}
+
+/**
+ * Validates signing date against request scope date and clock skew.
+ */
+private fun authDateValidation(writer: KotlinWriter) {
+    writer.write("val rawXAmzDate = call.request.#T(#S)", RuntimeTypes.KtorServerRouting.requestHeader, "X-Amz-Date")
+        .write("val rawHttpDate = call.request.#T(#T.Date)", RuntimeTypes.KtorServerRouting.requestHeader, RuntimeTypes.KtorServerHttp.HttpHeaders)
+        .withBlock("val signingInstant: #T = when {", "}", RuntimeTypes.Core.Instant) {
+            write("rawXAmzDate != null -> { try { #T.fromIso8601(rawXAmzDate) } catch (_: Exception) { return null } }", RuntimeTypes.Core.Instant)
+            write("rawHttpDate != null -> { try { #T.fromRfc5322(rawHttpDate) } catch (_: Exception) { return null } }", RuntimeTypes.Core.Instant)
+            write("else -> return null")
+        }
+        .write("val scopeDate = signingInstant.format(#T.ISO_8601_CONDENSED_DATE)", RuntimeTypes.Core.TimestampFormat)
+        .write("if (scopeDate != yyyyMMdd) return null")
+        .write("")
+        .write("val now = #T.now()", RuntimeTypes.Core.Instant)
+        .write("if (signingInstant < now - maxClockSkew || signingInstant > now + maxClockSkew) return null")
+}
+
+/**
+ * Builds a full HttpRequestBuilder object from the Ktor request,
+ * used for SigV4 canonical request signing.
+ */
+private fun createHttpRequestBuilder(writer: KotlinWriter) {
+    writer.write("val origin = call.request.local")
+        .write("val payload: ByteArray = call.#T<ByteArray>()", RuntimeTypes.KtorServerRouting.requestReceive)
+        .write("")
+        .withBlock("val requestBuilder: #T = #T().apply {", "}", RuntimeTypes.Http.Request.HttpRequestBuilder, RuntimeTypes.Http.Request.HttpRequestBuilder) {
+            write("method = #T.parse(call.request.#T.value)", RuntimeTypes.Http.HttpMethod, RuntimeTypes.KtorServerRouting.requestHttpMethod)
+            write("")
+            write("val protoHeader = call.request.headers[#S] ?: origin.scheme", "X-Forwarded-Proto")
+            write("val isHttps = (protoHeader.equals(#S, ignoreCase = true))", "https")
+            write("val hostHeader = call.request.headers[#S] ?: call.request.headers[#S] ?: return null", "X-Forwarded-Host", "Host")
+            write("val hostOnly: String")
+            write("val portValue: Int?")
+            withBlock("hostHeader.split(':', limit = 2).let {", "}") {
+                write("hostOnly = it[0]")
+                write("portValue = it.getOrNull(1)?.toIntOrNull()")
+            }
+            withBlock("#T {", "}", RuntimeTypes.Http.Request.url) {
+                write("scheme = if (isHttps) #T.HTTPS else #T.HTTP", RuntimeTypes.Core.Net.Scheme, RuntimeTypes.Core.Net.Scheme)
+                write("host = #T.parse(hostOnly)", RuntimeTypes.Core.Net.Host)
+                write("if (portValue != null) port = portValue")
+                withBlock("path {", "}") {
+                    write("decoded = call.request.#T()", RuntimeTypes.KtorServerRouting.requestPath)
+                }
+                withBlock("parameters {", "}") {
+                    withBlock("decodedParameters {", "}") {
+                        write("call.request.queryParameters.forEach { key, values -> values.forEach { v -> add(key, v) } }")
+                    }
+                }
+            }
+
+            write("")
+
+            withBlock("for (name in call.request.headers.names()) {", "}") {
+                write("val lowerName = name.lowercase()")
+                withBlock("if (lowerName != #T.Authorization.lowercase() && lowerName in signedHeaders) {", "}", RuntimeTypes.KtorServerHttp.HttpHeaders) {
+                    write("call.request.headers.getAll(name)?.forEach { value -> headers.append(name, value) }")
+                }
+            }
+
+            write("body = #T.fromBytes(payload)", RuntimeTypes.Http.HttpBody)
+        }
+}
+
+/**
+ * Builds a canonical request string for SigV4A verification.
+ */
+private fun createCanonicalRequest(writer: KotlinWriter) {
+    writer.write("val origin = call.request.local")
+        .write("val payload: ByteArray = call.#T<ByteArray>()", RuntimeTypes.KtorServerRouting.requestReceive)
+        .write("")
+        .write("val protoHeader = call.request.headers[#S] ?: origin.scheme", "X-Forwarded-Proto")
+        .write("val isHttps = (protoHeader.equals(#S, ignoreCase = true))", "https")
+        .write("val hostHeader = call.request.headers[#S] ?: call.request.headers[#S] ?: return null", "X-Forwarded-Host", "Host")
+        .write("val hostOnly: String")
+        .write("val portValue: Int?")
+        .withBlock("hostHeader.split(':', limit = 2).let {", "}") {
+            write("hostOnly = it[0]")
+            write("portValue = it.getOrNull(1)?.toIntOrNull()")
+        }
+        .write("")
+        .write("val canonicalUri = encodeCanonicalPath(call.request.#T())", RuntimeTypes.KtorServerRouting.requestPath)
+        .write("val canonicalQuery = buildCanonicalQuery(#T.build { call.request.queryParameters.forEach { k, vs -> vs.forEach { v -> append(k, v) } } })", RuntimeTypes.KtorServerHttp.Parameters)
+        .write("")
+        .withBlock("val filteredHeaders = #T().apply {", "}.build()", RuntimeTypes.KtorServerHttp.HeadersBuilder) {
+            withBlock("for (name in call.request.headers.names()) {", "}") {
+                write("val ln = name.lowercase()")
+                withBlock("if (ln != HttpHeaders.Authorization.lowercase() && ln in signedHeaders) {", "}") {
+                    write("call.request.headers.getAll(name)?.forEach { v -> append(name, v) }")
+                }
+            }
+            withBlock("if (!names().any { it.equals(#S, ignoreCase = true) }) {", "}", "X-Amz-Region-Set") {
+                write("append(#S, rawRegionSet)", "X-Amz-Region-Set")
+            }
+            withBlock("if (!names().any { it.equals(#S, ignoreCase = true) }) {", "}", "Host") {
+                write("val defaultPort = (isHttps && portValue == 443) || (!isHttps && portValue == 80)")
+                write("append(#S, if (portValue != null && !defaultPort) #S else hostOnly) ", "Host", "\$hostOnly:\$portValue")
+            }
+        }
+        .withBlock("val (canonicalHeaders, signedHeaderList) = run {", "}") {
+            write("val map = mutableMapOf<String, MutableList<String>>()")
+            withBlock("filteredHeaders.names().forEach { name ->", "}") {
+                write("val ln = name.lowercase()")
+                withBlock("if (ln in signedHeaders) {", "}") {
+                    write("val values = filteredHeaders.getAll(name).orEmpty()")
+                    write("    .map { it.trim().replace(Regex(#S), #S) }", "\\s+", " ")
+                    write("map.getOrPut(ln) { mutableListOf() }.addAll(values)")
+                }
+            }
+            withBlock("if (#S !in map) {", "}", "x-amz-region-set") {
+                write("map[#S] = mutableListOf(rawRegionSet)", "x-amz-region-set")
+            }
+            withBlock("val canon = map.toSortedMap().entries.joinToString(#S, postfix = #S) { entry ->", "}", "\n", "\n") {
+                write("val key = entry.key")
+                write("val vs = entry.value")
+                write("\"\$key:\${vs.joinToString(#S)}\"", ",")
+            }
+
+            write("val signedList = map.keys.sorted().joinToString(#S)", ";")
+            write("canon to signedList")
+        }
+        .write("val payloadHash = if (isUnsigned) #S else { sha256Hex(payload) }", "UNSIGNED-PAYLOAD")
+        .withBlock("val canonicalRequest = buildString {", "}") {
+            write("append(call.request.#T.value.uppercase()).append('\\n')", RuntimeTypes.KtorServerRouting.requestHttpMethod)
+            write("append(canonicalUri).append('\\n')")
+            write("append(canonicalQuery).append('\\n')")
+            write("append(canonicalHeaders)")
+            write("append('\\n')") // empty line before SignedHeaders list
+            write("append(signedHeaderList).append('\\n')")
+            write("append(payloadHash)")
+        }
+}
+
+/**
+ * Performs AWS SigV4 signature validation against expected HMAC.
+ */
+private fun validateSigV4(writer: KotlinWriter) {
+    writer.withBlock("val signer = #T(", ")", RuntimeTypes.Auth.HttpAuthAws.AwsHttpSigner) {
+        withBlock("#T.Config().apply {", "}", RuntimeTypes.Auth.HttpAuthAws.AwsHttpSigner) {
+            write("this.signer = #T", RuntimeTypes.Auth.Signing.AwsSigningStandard.DefaultAwsSigner)
+            write("this.service = service")
+            write("this.isUnsignedPayload = isUnsigned")
+        }
+    }
+        .withBlock("val attrs = #T {", "}", RuntimeTypes.Core.Collections.attributesOf) {
+            write("#T to creds", RuntimeTypes.Auth.Credentials.AwsCredentials.Credentials)
+            write("#T.SigningRegion to region", RuntimeTypes.Auth.Signing.AwsSigningCommon.AwsSigningAttributes)
+            write("#T.SigningDate to signingInstant", RuntimeTypes.Auth.Signing.AwsSigningCommon.AwsSigningAttributes)
+            withBlock("if (isUnsigned) {", "}") {
+                write(
+                    "#T.HashSpecification to #T.UnsignedPayload",
+                    RuntimeTypes.Auth.Signing.AwsSigningCommon.AwsSigningAttributes,
+                    RuntimeTypes.Auth.Signing.AwsSigningCommon.HashSpecification,
+                )
+                write(
+                    "#T.SignedBodyHeader to #T.NONE",
+                    RuntimeTypes.Auth.Signing.AwsSigningCommon.AwsSigningAttributes,
+                    RuntimeTypes.Auth.Signing.AwsSigningCommon.AwsSignedBodyHeader,
+                )
+            }
+        }
+        .write(
+            "signer.sign(#T(requestBuilder, creds, attrs))",
+            RuntimeTypes.Auth.HttpAuthAws.SignHttpRequest,
+        )
+        .write(
+            "val expectedAuth = requestBuilder.headers.getAll(#T.Authorization)?.firstOrNull() ?: return null",
+            RuntimeTypes.KtorServerHttp.HttpHeaders,
+        )
+        .write("val expectedSig = expectedAuth.substringAfter(#S).trim()", "Signature=")
+}
+
+/**
+ * Performs AWS SigV4A signature validation against ECDSA public key.
+ */
+private fun validateSigV4A(writer: KotlinWriter) {
+    writer.write("val crHashHex = sha256Hex(canonicalRequest.toByteArray())")
+        .withBlock("val stringToSign = buildString {", "}") {
+            write("append(#S).append('\\n')", "AWS4-ECDSA-P256-SHA256")
+            write("append(signingInstant.format(#T.ISO_8601_CONDENSED)).append('\\n')", RuntimeTypes.Core.TimestampFormat)
+            write("append(#S).append('\\n')", "\$yyyyMMdd/\$service/aws4_request")
+            write("append(crHashHex)")
+        }
+        .write("val publicKey: java.security.PublicKey = SigV4aPublicKeyStore.get(accessKeyId) ?: return null")
+        .write("val sigDer = signatureHex.chunked(2).map { it.toInt(16).toByte() }.toByteArray()")
+        .write("val verifier = java.security.Signature.getInstance(#S)", "SHA256withECDSA")
+        .write("verifier.initVerify(publicKey)")
+        .write("verifier.update(stringToSign.toByteArray())")
+        .write("val ok = verifier.verify(sigDer)")
+}
+
+/**
+ * Writes common helper functions used by SigV4 and SigV4A verification,
+ * such as hashing, encoding, and canonical path/query building.
+ */
+private fun renderHelperFunctions(writer: KotlinWriter) {
+    writer.withBlock("private fun sha256Hex(bytes: ByteArray): String {", "}") {
+        write("return java.security.MessageDigest.getInstance(#S).digest(bytes).joinToString(#S) { #S.format(it) }", "SHA-256", "", "%02x")
+    }
+        .write("")
+
+    writer.withBlock("private val UNRESERVED: BooleanArray = BooleanArray(128).apply {", "}") {
+        write("for (c in 'A'..'Z') this[c.code] = true")
+        write("for (c in 'a'..'z') this[c.code] = true")
+        write("for (c in '0'..'9') this[c.code] = true")
+        write("this['-'.code] = true; this['_'.code] = true; this['.'.code] = true; this['~'.code] = true\n")
+    }
+        .write("")
+
+    writer.withBlock("private fun rfc3986Encode(bytes: ByteArray): String {", "}") {
+        write("val out = StringBuilder(bytes.size * 3)")
+        withBlock("for (b in bytes) {", "}") {
+            write("val i = b.toInt() and 0xFF")
+            withInlineBlock("if (i < 128 && UNRESERVED[i]) {", "}") {
+                write("out.append(i.toChar())")
+            }
+            withBlock(" else {", "}") {
+                write("out.append('%')")
+                write("val hi = #S[(i ushr 4) and 0xF]", "0123456789ABCDEF")
+                write("val lo = #S[i and 0xF]", "0123456789ABCDEF")
+                write("out.append(hi).append(lo)")
+            }
+        }
+        write("return out.toString()")
+    }
+        .write("")
+    writer.write("private fun encodeString(s: String): String = rfc3986Encode(s.toByteArray(Charsets.UTF_8))")
+        .write("")
+
+    writer.withBlock("private fun encodeCanonicalPath(rawPath: String): String {", "}") {
+        write("val p = if (rawPath.isEmpty()) #S else rawPath", "/")
+        write("return p.split('/').joinToString(#S) { seg -> if (seg.isEmpty()) #S else encodeString(seg) }", "/", "")
+    }
+        .write("")
+
+    writer.withBlock("private fun buildCanonicalQuery(params: #T): String {", "}", RuntimeTypes.KtorServerHttp.Parameters) {
+        withBlock("val pairs = buildList {", "}") {
+            withBlock("params.names().sorted().forEach { name ->", "}") {
+                write("val values = params.getAll(name)")
+                openBlock("if (values == null || values.isEmpty()) {")
+                write("add(#S)", "\${encodeString(name)}=")
+                closeAndOpenBlock("} else {")
+                write("values.sorted().forEach { v -> add(#S) }", "\${encodeString(name)}=\${encodeString(v)}")
+                closeBlock("}")
+            }
+        }
+        write("return pairs.joinToString(#S)", "&")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/KtorStubGenerator.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/KtorStubGenerator.kt
new file mode 100644
index 0000000000..e578020e81
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/KtorStubGenerator.kt
@@ -0,0 +1,67 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
+import software.amazon.smithy.kotlin.codegen.core.InlineCodeWriterFormatter
+import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.service.AbstractStubGenerator
+import software.amazon.smithy.kotlin.codegen.service.constraints.ConstraintGenerator
+import software.amazon.smithy.kotlin.codegen.service.constraints.ConstraintUtilsGenerator
+import software.amazon.smithy.utils.AbstractCodeWriter
+
+class LoggingWriter(parent: LoggingWriter? = null) : AbstractCodeWriter<LoggingWriter>() {
+    init {
+        trimBlankLines(parent?.trimBlankLines ?: 1)
+        trimTrailingSpaces(parent?.trimTrailingSpaces ?: true)
+        indentText = parent?.indentText ?: "    "
+        expressionStart = parent?.expressionStart ?: '#'
+        putFormatter('W', InlineCodeWriterFormatter(::LoggingWriter))
+    }
+}
+
+/**
+ * Stub generator for Ktor-based services.
+ *
+ * Implements [AbstractStubGenerator] for the Ktor runtime, generating:
+ * - Framework implementation
+ * - Utilities
+ * - Authentication modules
+ * - Constraint validators
+ * - Routing tables
+ * - Plugins
+ * - Operation handlers
+ */
+internal class KtorStubGenerator(
+    ctx: GenerationContext,
+    delegator: KotlinDelegator,
+    fileManifest: FileManifest,
+) : AbstractStubGenerator(ctx, delegator, fileManifest) {
+
+    /** Generate the Ktor server framework implementation. */
+    override fun renderServerFrameworkImplementation(writer: KotlinWriter) = writeServerFrameworkImplementation(writer)
+
+    /** Generate utility classes and helpers. */
+    override fun renderUtils() = writeUtils()
+
+    /** Generate authentication modules (AWS auth + bearer/no-auth). */
+    override fun renderAuthModule() {
+        writeAWSAuthentication()
+        writeAuthentication()
+    }
+
+    /** Generate request constraint validators for all operations. */
+    override fun renderConstraintValidators() {
+        ConstraintUtilsGenerator(ctx, delegator).render()
+        operations.forEach { operation -> ConstraintGenerator(ctx, operation, delegator).render() }
+    }
+
+    /** Generate routing file mapping Smithy operations to Ktor routes. */
+    override fun renderRouting() = writeRouting()
+
+    /** Generate plugin configurations (e.g., error handlers, guards). */
+    override fun renderPlugins() = writePlugins()
+
+    /** Generate stub handler files for each Smithy operation. */
+    override fun renderPerOperationHandlers() = writePerOperationHandlers()
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/OperationHandlers.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/OperationHandlers.kt
new file mode 100644
index 0000000000..b9be8a925b
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/OperationHandlers.kt
@@ -0,0 +1,51 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+
+/**
+ * Generates stub handler files for each Smithy operation.
+ *
+ * For every operation, this creates an `OperationNameOperation.kt` file
+ * under the `operations` package containing:
+ * - A `handle<OperationName>Request()` function
+ * - TODO implementation guidance for constructing response objects
+ * - Documentation of available custom errors
+ *
+ * Each generated handler accepts the operation's input type and returns
+ * the operation's output type.
+ */
+internal fun KtorStubGenerator.writePerOperationHandlers() {
+    operations.forEach { shape ->
+        val inputShape = ctx.model.expectShape(shape.input.get())
+        val inputSymbol = ctx.symbolProvider.toSymbol(inputShape)
+
+        val outputShape = ctx.model.expectShape(shape.output.get())
+        val outputSymbol = ctx.symbolProvider.toSymbol(outputShape)
+
+        val name = shape.id.name
+
+        delegator.useFileWriter("${name}Operation.kt", "$pkgName.operations") { writer ->
+
+            writer.withBlock("public fun handle${name}Request(req: #T): #T {", "}", inputSymbol, outputSymbol) {
+                write("// TODO: implement me")
+                write("// To build a #T object:", outputSymbol)
+                write("//   1. Use`#T.Builder()`", outputSymbol)
+                write("//   2. Set fields like `#T.variable = ...`", outputSymbol)
+                write("//   3. Return the built object using `return #T.build()`", outputSymbol)
+                write("//")
+                val errorSymbolNames: List<String> = shape.errors.map { errorShapeId ->
+                    val errorShape = ctx.model.expectShape(errorShapeId)
+                    ctx.symbolProvider.toSymbol(errorShape).name
+                }
+                write("// You may also throw custom errors if needed.")
+                write("// Custom errors can be created using the same builder pattern.")
+                if (errorSymbolNames.isNotEmpty()) {
+                    write("// Available errors : ${errorSymbolNames.joinToString(", ")}")
+                } else {
+                    write("// There are no available errors for this operation.")
+                }
+                write("return #T.Builder().build()", outputSymbol)
+            }
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Plugins.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Plugins.kt
new file mode 100644
index 0000000000..d39b519ee0
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Plugins.kt
@@ -0,0 +1,293 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.core.withInlineBlock
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+
+/**
+ * Entry point for writing plugin modules (error handling, content-type guard, accept-type guard).
+ *
+ * Generates three files under the `plugins` package:
+ * - `ErrorHandler.kt`: common error envelope and exception-to-response mapping
+ * - `ContentTypeGuard.kt`: validates request `Content-Type` header
+ * - `AcceptTypeGuard.kt`: validates request `Accept` header
+ */
+internal fun KtorStubGenerator.writePlugins() {
+    renderErrorHandler()
+    renderContentTypeGuard()
+    renderAcceptTypeGuard()
+}
+
+/**
+ * Generates `ErrorHandler.kt`, which contains:
+ * - `ErrorEnvelope` exception wrapper for standard error responses
+ * - JSON and CBOR serialization for error payloads
+ * - Extension to respond with an `ErrorEnvelope`
+ * - `configureErrorHandling()` that installs a `StatusPages` plugin
+ *   mapping HTTP status codes and exceptions → structured error responses
+ */
+private fun KtorStubGenerator.renderErrorHandler() {
+    delegator.useFileWriter("ErrorHandler.kt", "$pkgName.plugins") { writer ->
+        writer.write("internal val ResponseHandledKey = #T<Boolean>(#S)", RuntimeTypes.KtorServerUtils.AttributeKey, "ResponseHandled")
+            .write("")
+        writer.write("@#T", RuntimeTypes.KotlinxCborSerde.Serializable)
+            .write("private data class ErrorPayload(val code: Int, val message: String)")
+            .write("")
+            .withInlineBlock("internal class ErrorEnvelope(", ")") {
+                write("val code: Int,")
+                write("val msg: String,")
+                write("cause: Throwable? = null,")
+            }
+            .withBlock(" : RuntimeException(msg, cause) {", "}") {
+                withBlock("fun toJson(json: #T = #T): String {", "}", RuntimeTypes.KotlinxJsonSerde.Json, RuntimeTypes.KotlinxJsonSerde.Json) {
+                    withInlineBlock("return json.encodeToString(", ")") {
+                        write("ErrorPayload(code, message ?: #S)", "Unknown error")
+                    }
+                }
+                withBlock("fun toCbor(cbor: #T = #T { }): ByteArray {", "}", RuntimeTypes.KotlinxCborSerde.Cbor, RuntimeTypes.KotlinxCborSerde.Cbor) {
+                    withInlineBlock("return cbor.#T(", ")", RuntimeTypes.KotlinxCborSerde.encodeToByteArray) {
+                        write("ErrorPayload(code, message ?: #S)", "Unknown error")
+                    }
+                }
+            }
+            .write("")
+            .withInlineBlock("private suspend fun #T.respondEnvelope(", ")", RuntimeTypes.KtorServerCore.ApplicationCallClass) {
+                write("envelope: ErrorEnvelope,")
+                write("status: #T,", RuntimeTypes.KtorServerHttp.HttpStatusCode)
+            }
+            .withBlock("{", "}") {
+                write("val acceptsCbor = request.#T().any { it.value == #S }", RuntimeTypes.KtorServerRouting.requestAcceptItems, "application/cbor")
+                write("val acceptsJson = request.#T().any { it.value == #S }", RuntimeTypes.KtorServerRouting.requestAcceptItems, "application/json")
+                write("")
+                write("val log = #T.getLogger(#S)", RuntimeTypes.KtorLoggingSlf4j.LoggerFactory, pkgName)
+                write("log.info(#S)", "Route Error Message: \${envelope.msg}")
+                write("")
+                withBlock("when {", "}") {
+                    withBlock("acceptsCbor -> {", "}") {
+                        withBlock("#T(", ")", RuntimeTypes.KtorServerRouting.responseRespondBytes) {
+                            write("bytes = envelope.toCbor(),")
+                            write("status = status,")
+                            write("contentType = #T", RuntimeTypes.KtorServerHttp.Cbor)
+                        }
+                    }
+                    withBlock("acceptsJson -> {", "}") {
+                        withBlock("#T(", ")", RuntimeTypes.KtorServerRouting.responseResponseText) {
+                            write("envelope.toJson(),")
+                            write("status = status,")
+                            write("contentType = #T", RuntimeTypes.KtorServerHttp.Json)
+                        }
+                    }
+                    withBlock("else -> {", "}") {
+                        withBlock("#T(", ")", RuntimeTypes.KtorServerRouting.responseResponseText) {
+                            write("envelope.msg,")
+                            write("status = status")
+                        }
+                    }
+                }
+            }
+            .write("")
+            .withBlock("internal fun #T.configureErrorHandling() {", "}", RuntimeTypes.KtorServerCore.Application) {
+                write("")
+                withBlock(
+                    "#T(#T) {",
+                    "}",
+                    RuntimeTypes.KtorServerCore.install,
+                    RuntimeTypes.KtorServerStatusPage.StatusPages,
+                ) {
+                    withBlock("status(#T.Unauthorized) { call, status ->", "}", RuntimeTypes.KtorServerHttp.HttpStatusCode) {
+                        write("if (call.attributes.getOrNull(#T) == true) { return@status }", ServiceTypes(pkgName).responseHandledKey)
+                        write("call.attributes.put(#T, true)", ServiceTypes(pkgName).responseHandledKey)
+                        write("val missing = call.request.headers[#S].isNullOrBlank()", "Authorization")
+                        write("val message = if (missing) #S else #S", "Missing bearer token", "Invalid or expired authentication")
+                        write("call.respondEnvelope( ErrorEnvelope(status.value, message), status )")
+                    }
+                    write("")
+                    withBlock("status(#T.NotFound) { call, status ->", "}", RuntimeTypes.KtorServerHttp.HttpStatusCode) {
+                        write("if (call.attributes.getOrNull(#T) == true) { return@status }", ServiceTypes(pkgName).responseHandledKey)
+                        write("call.attributes.put(#T, true)", ServiceTypes(pkgName).responseHandledKey)
+                        write("val message = #S", "Resource not found")
+                        write("call.respondEnvelope( ErrorEnvelope(status.value, message), status )")
+                    }
+                    write("")
+                    withBlock("status(#T.MethodNotAllowed) { call, status ->", "}", RuntimeTypes.KtorServerHttp.HttpStatusCode) {
+                        write("if (call.attributes.getOrNull(#T) == true) { return@status }", ServiceTypes(pkgName).responseHandledKey)
+                        write("call.attributes.put(#T, true)", ServiceTypes(pkgName).responseHandledKey)
+                        write("val message = #S", "Method not allowed for this resource")
+                        write("call.respondEnvelope( ErrorEnvelope(status.value, message), status )")
+                    }
+                    write("")
+                    withBlock("#T<Throwable> { call, cause ->", "}", RuntimeTypes.KtorServerStatusPage.exception) {
+                        withBlock("val status = when (cause) {", "}") {
+                            write(
+                                "is ErrorEnvelope -> #T.fromValue(cause.code)",
+                                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+                            )
+                            write(
+                                "is #T -> #T.BadRequest",
+                                RuntimeTypes.KtorServerCore.BadRequestException,
+                                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+                            )
+                            write(
+                                "is #T -> #T.PayloadTooLarge",
+                                RuntimeTypes.KtorServerBodyLimit.PayloadTooLargeException,
+                                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+                            )
+                            write("else -> #T.InternalServerError", RuntimeTypes.KtorServerHttp.HttpStatusCode)
+                        }
+                        write("")
+
+                        write("val envelope = if (cause is ErrorEnvelope) cause else ErrorEnvelope(status.value, cause.message ?: #S)", "Unexpected error")
+                        write("call.attributes.put(#T, true)", ServiceTypes(pkgName).responseHandledKey)
+                        write("call.respondEnvelope( envelope, status )")
+                    }
+                }
+            }
+    }
+}
+
+/**
+ * Generates `ContentTypeGuard.kt`, which installs a route-scoped plugin that:
+ * - Defines a configurable allow-list of acceptable request `Content-Type`s
+ * - Rejects unsupported media types with an `ErrorEnvelope`
+ * - Provides convenience configuration (e.g., `json()`, `cbor()`, `binary()`)
+ */
+private fun KtorStubGenerator.renderContentTypeGuard() {
+    delegator.useFileWriter("ContentTypeGuard.kt", "$pkgName.plugins") { writer ->
+
+        writer.withBlock("private fun #T.hasBody(): Boolean {", "}", RuntimeTypes.KtorServerRouting.requestApplicationRequest) {
+            write(
+                "return (#T()?.let { it > 0 } == true) || headers.contains(#T.TransferEncoding)",
+                RuntimeTypes.KtorServerRouting.requestContentLength,
+                RuntimeTypes.KtorServerHttp.HttpHeaders,
+            )
+        }
+        writer.withBlock("public class ContentTypeGuardConfig {", "}") {
+            write("public var allow: List<#T> = emptyList()", RuntimeTypes.KtorServerHttp.ContentType)
+            write("")
+            withBlock("public fun any(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Any)
+            }
+            write("")
+            withBlock("public fun json(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Json)
+            }
+            write("")
+            withBlock("public fun cbor(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Cbor)
+            }
+            write("")
+            withBlock("public fun text(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.PlainText)
+            }
+            write("")
+            withBlock("public fun binary(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.OctetStream)
+            }
+        }
+            .write("")
+
+        writer.withInlineBlock(
+            "public val ContentTypeGuard: #T<ContentTypeGuardConfig> = #T(",
+            ")",
+            RuntimeTypes.KtorServerCore.ApplicationRouteScopedPlugin,
+            RuntimeTypes.KtorServerCore.ApplicationCreateRouteScopedPlugin,
+        ) {
+            write("name = #S,", "ContentTypeGuard")
+            write("createConfiguration = ::ContentTypeGuardConfig,")
+        }
+            .withBlock("{", "}") {
+                write("val allowed: List<#T> = pluginConfig.allow", RuntimeTypes.KtorServerHttp.ContentType)
+                write("require(allowed.isNotEmpty()) { #S }", "ContentTypeGuard installed with empty allow-list.")
+                write("")
+                withBlock("onCall { call ->", "}") {
+                    write("if (!call.request.hasBody()) return@onCall")
+                    write("val incoming = call.request.#T()", RuntimeTypes.KtorServerRouting.requestContentType)
+                    withBlock("if (incoming == #T.Any || allowed.none { incoming.match(it) }) {", "}", RuntimeTypes.KtorServerHttp.ContentType) {
+                        withBlock("throw #T(", ")", ServiceTypes(pkgName).errorEnvelope) {
+                            write("#T.UnsupportedMediaType.value, ", RuntimeTypes.KtorServerHttp.HttpStatusCode)
+                            write("#S", "Not acceptable Content‑Type found: '\${incoming}'. Accepted content types: \${allowed.joinToString()}")
+                        }
+                    }
+                }
+            }
+    }
+}
+
+/**
+ * Generates `AcceptTypeGuard.kt`, which installs a route-scoped plugin that:
+ * - Defines a configurable allow-list of acceptable `Accept` header values
+ * - Rejects unsupported response types with an `ErrorEnvelope`
+ * - Provides convenience configuration (e.g., `json()`, `cbor()`, `text()`)
+ */
+private fun KtorStubGenerator.renderAcceptTypeGuard() {
+    delegator.useFileWriter("AcceptTypeGuard.kt", "${ctx.settings.pkg.name}.plugins") { writer ->
+
+        writer.withBlock(
+            "private fun #T.acceptedContentTypes(): List<#T> {",
+            "}",
+            RuntimeTypes.KtorServerRouting.requestApplicationRequest,
+            RuntimeTypes.KtorServerHttp.ContentType,
+        ) {
+            write("val raw = headers[#T.Accept] ?: return emptyList()", RuntimeTypes.KtorServerHttp.HttpHeaders)
+            write(
+                "return #T(raw).mapNotNull { it.value?.let(#T::parse) }",
+                RuntimeTypes.KtorServerHttp.parseAndSortHeader,
+                RuntimeTypes.KtorServerHttp.ContentType,
+            )
+        }
+
+        writer.withBlock("public class AcceptTypeGuardConfig {", "}") {
+            write("public var allow: List<#T> = emptyList()", RuntimeTypes.KtorServerHttp.ContentType)
+            write("")
+            withBlock("public fun any(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Any)
+            }
+            write("")
+            withBlock("public fun json(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Json)
+            }
+            write("")
+            withBlock("public fun cbor(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.Cbor)
+            }
+            write("")
+            withBlock("public fun text(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.PlainText)
+            }
+            write("")
+            withBlock("public fun binary(): Unit {", "}") {
+                write("allow = listOf(#T)", RuntimeTypes.KtorServerHttp.OctetStream)
+            }
+        }
+            .write("")
+
+        writer.withInlineBlock(
+            "public val AcceptTypeGuard: #T<AcceptTypeGuardConfig> = #T(",
+            ")",
+            RuntimeTypes.KtorServerCore.ApplicationRouteScopedPlugin,
+            RuntimeTypes.KtorServerCore.ApplicationCreateRouteScopedPlugin,
+        ) {
+            write("name = #S,", "AcceptTypeGuard")
+            write("createConfiguration = ::AcceptTypeGuardConfig,")
+        }
+            .withBlock("{", "}") {
+                write("val allowed: List<#T> = pluginConfig.allow", RuntimeTypes.KtorServerHttp.ContentType)
+                write("require(allowed.isNotEmpty()) { #S }", "AcceptTypeGuard installed with empty allow-list.")
+                write("")
+                withBlock("onCall { call ->", "}") {
+                    write("val accepted = call.request.acceptedContentTypes()")
+                    write("if (accepted.isEmpty()) return@onCall")
+                    write("")
+                    write("val isOk = accepted.any { candidate -> allowed.any { candidate.match(it) } }")
+
+                    withBlock("if (!isOk) {", "}") {
+                        withBlock("throw #T(", ")", ServiceTypes(pkgName).errorEnvelope) {
+                            write("#T.NotAcceptable.value, ", RuntimeTypes.KtorServerHttp.HttpStatusCode)
+                            write("#S", "Not acceptable Accept type found: '\${accepted}'. Accepted types: \${allowed.joinToString()}")
+                        }
+                    }
+                }
+            }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Routing.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Routing.kt
new file mode 100644
index 0000000000..2a09b38cf0
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Routing.kt
@@ -0,0 +1,470 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.aws.traits.auth.SigV4ATrait
+import software.amazon.smithy.aws.traits.auth.SigV4Trait
+import software.amazon.smithy.codegen.core.SymbolReference
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.core.withInlineBlock
+import software.amazon.smithy.kotlin.codegen.model.buildSymbol
+import software.amazon.smithy.kotlin.codegen.model.getTrait
+import software.amazon.smithy.kotlin.codegen.rendering.serde.deserializerName
+import software.amazon.smithy.kotlin.codegen.rendering.serde.serializerName
+import software.amazon.smithy.kotlin.codegen.service.MediaType
+import software.amazon.smithy.kotlin.codegen.service.MediaType.ANY
+import software.amazon.smithy.kotlin.codegen.service.MediaType.JSON
+import software.amazon.smithy.kotlin.codegen.service.MediaType.OCTET_STREAM
+import software.amazon.smithy.kotlin.codegen.service.MediaType.PLAIN_TEXT
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+import software.amazon.smithy.kotlin.codegen.service.renderCastingPrimitiveFromShapeType
+import software.amazon.smithy.model.shapes.MapShape
+import software.amazon.smithy.model.shapes.OperationShape
+import software.amazon.smithy.model.shapes.ShapeId
+import software.amazon.smithy.model.traits.AuthTrait
+import software.amazon.smithy.model.traits.HttpBearerAuthTrait
+import software.amazon.smithy.model.traits.HttpErrorTrait
+import software.amazon.smithy.model.traits.HttpHeaderTrait
+import software.amazon.smithy.model.traits.HttpLabelTrait
+import software.amazon.smithy.model.traits.HttpPrefixHeadersTrait
+import software.amazon.smithy.model.traits.HttpQueryParamsTrait
+import software.amazon.smithy.model.traits.HttpQueryTrait
+import software.amazon.smithy.model.traits.HttpTrait
+import software.amazon.smithy.model.traits.MediaTypeTrait
+import software.amazon.smithy.model.traits.TimestampFormatTrait
+
+/**
+ * Generates Ktor server routing for all operations in the service model.
+ *
+ * - Creates `Routing.kt` file.
+ * - Installs appropriate content-type and accept-type guards.
+ * - Handles request deserialization, validation, business logic invocation,
+ *   response serialization, and error handling.
+ */
+internal fun KtorStubGenerator.writeRouting() {
+    delegator.useFileWriter("Routing.kt", pkgName) { writer ->
+        operations.forEach { shape ->
+            writer.addImport("$pkgName.constraints", "check${shape.id.name}RequestConstraint")
+            writer.addImport("$pkgName.operations", "handle${shape.id.name}Request")
+        }
+
+        writer.withBlock("internal fun #T.configureRouting(): Unit {", "}", RuntimeTypes.KtorServerCore.Application) {
+            withBlock("#T {", "}", RuntimeTypes.KtorServerRouting.routing) {
+                withBlock("#T(#S) {", "}", RuntimeTypes.KtorServerRouting.get, "/") {
+                    write(" #T.#T(#S)", RuntimeTypes.KtorServerCore.applicationCall, RuntimeTypes.KtorServerRouting.responseResponseText, "hello world")
+                }
+                operations.filter { it.hasTrait(HttpTrait.ID) }
+                    .forEach { shape ->
+                        val inputShape = ctx.model.expectShape(shape.input.get())
+                        val inputSymbol = ctx.symbolProvider.toSymbol(inputShape)
+
+                        val outputShape = ctx.model.expectShape(shape.output.get())
+                        val outputSymbol = ctx.symbolProvider.toSymbol(outputShape)
+
+                        val serializerSymbol = buildSymbol {
+                            definitionFile = "${shape.serializerName()}.kt"
+                            name = shape.serializerName()
+                            namespace = ctx.settings.pkg.serde
+                            reference(inputSymbol, SymbolReference.ContextOption.DECLARE)
+                        }
+                        val deserializerSymbol = buildSymbol {
+                            definitionFile = "${shape.deserializerName()}.kt"
+                            name = shape.deserializerName()
+                            namespace = ctx.settings.pkg.serde
+                            reference(outputSymbol, SymbolReference.ContextOption.DECLARE)
+                        }
+
+                        val httpTrait = shape.getTrait<HttpTrait>()!!
+
+                        val uri = httpTrait.uri
+                        val successCode = httpTrait.code
+                        val method = when (httpTrait.method) {
+                            "GET" -> RuntimeTypes.KtorServerRouting.get
+                            "POST" -> RuntimeTypes.KtorServerRouting.post
+                            "PUT" -> RuntimeTypes.KtorServerRouting.put
+                            "PATCH" -> RuntimeTypes.KtorServerRouting.patch
+                            "DELETE" -> RuntimeTypes.KtorServerRouting.delete
+                            "HEAD" -> RuntimeTypes.KtorServerRouting.head
+                            "OPTIONS" -> RuntimeTypes.KtorServerRouting.options
+                            else -> error("Unsupported http trait ${httpTrait.method}")
+                        }
+                        val contentType = MediaType.fromServiceShape(ctx, serviceShape, shape.input.get())
+                        val contentTypeGuard = when (contentType) {
+                            MediaType.CBOR -> "cbor()"
+                            JSON -> "json()"
+                            PLAIN_TEXT -> "text()"
+                            OCTET_STREAM -> "binary()"
+                            ANY -> "any()"
+                        }
+
+                        val acceptType = MediaType.fromServiceShape(ctx, serviceShape, shape.output.get())
+                        val acceptTypeGuard = when (acceptType) {
+                            MediaType.CBOR -> "cbor()"
+                            JSON -> "json()"
+                            PLAIN_TEXT -> "text()"
+                            OCTET_STREAM -> "binary()"
+                            ANY -> "any()"
+                        }
+
+                        withBlock("#T (#S) {", "}", RuntimeTypes.KtorServerRouting.route, uri) {
+                            write("#T(#T) { $contentTypeGuard }", RuntimeTypes.KtorServerCore.install, ServiceTypes(pkgName).contentTypeGuard)
+                            write("#T(#T) { $acceptTypeGuard }", RuntimeTypes.KtorServerCore.install, ServiceTypes(pkgName).acceptTypeGuard)
+                            withBlock(
+                                "#W",
+                                "}",
+                                { w: KotlinWriter -> renderRoutingAuth(w, shape) },
+                            ) {
+                                withBlock("#T {", "}", method) {
+                                    withInlineBlock("try {", "}") {
+                                        write(
+                                            "val request = #T.#T<ByteArray>()",
+                                            RuntimeTypes.KtorServerCore.applicationCall,
+                                            RuntimeTypes.KtorServerRouting.requestReceive,
+                                        )
+                                        write("val deserializer = #T()", deserializerSymbol)
+                                        withBlock(
+                                            "var requestObj = try { deserializer.deserialize(#T(), call, request) } catch (ex: Exception) {",
+                                            "}",
+                                            RuntimeTypes.Core.ExecutionContext,
+                                        ) {
+                                            write(
+                                                "throw #T(ex?.message ?: #S, ex)",
+                                                RuntimeTypes.KtorServerCore.BadRequestException,
+                                                "Malformed input data",
+                                            )
+                                        }
+                                        if (ctx.model.expectShape(shape.input.get()).allMembers.isNotEmpty()) {
+                                            withBlock("requestObj = requestObj.copy {", "}") {
+                                                call { readHttpLabel(shape, writer) }
+                                                call { readHttpQuery(shape, writer) }
+                                            }
+                                        }
+
+                                        write(
+                                            "try { check${shape.id.name}RequestConstraint(requestObj) } catch (ex: Exception) { throw #T(ex?.message ?: #S, ex) }",
+                                            RuntimeTypes.KtorServerCore.BadRequestException,
+                                            "Error while validating constraints",
+                                        )
+                                        write("val responseObj = handle${shape.id.name}Request(requestObj)")
+                                        write("val serializer = #T()", serializerSymbol)
+                                        withBlock(
+                                            "val response = try { serializer.serialize(#T(), responseObj) } catch (ex: Exception) {",
+                                            "}",
+                                            RuntimeTypes.Core.ExecutionContext,
+                                        ) {
+                                            write(
+                                                "throw #T(ex?.message ?: #S, ex)",
+                                                RuntimeTypes.KtorServerCore.BadRequestException,
+                                                "Malformed output data",
+                                            )
+                                        }
+                                        call { readResponseHttpHeader("responseObj", shape.output.get(), writer) }
+                                        call { readResponseHttpPrefixHeader("responseObj", shape.output.get(), writer) }
+                                        call { renderResponseCall("response", writer, acceptType, successCode.toString(), shape.output.get()) }
+                                    }
+                                    withBlock(" catch (t: Throwable) {", "}") {
+                                        writeInline("val errorObj: Any? = ")
+                                        withBlock("when (t) {", "}") {
+                                            shape.errors.forEach { errorShapeId ->
+                                                val errorShape = ctx.model.expectShape(errorShapeId)
+                                                val errorSymbol = ctx.symbolProvider.toSymbol(errorShape)
+                                                write("is #T -> t as #T", errorSymbol, errorSymbol)
+                                            }
+                                            write("else -> null")
+                                        }
+                                        write("")
+                                        writeInline("val errorResponse: Pair<Any, Int>? = ")
+                                        withBlock("when (errorObj) {", "}") {
+                                            shape.errors.forEach { errorShapeId ->
+                                                val errorShape = ctx.model.expectShape(errorShapeId)
+                                                val errorSymbol = ctx.symbolProvider.toSymbol(errorShape)
+                                                val exceptionSymbol = buildSymbol {
+                                                    val exceptionName = "${errorSymbol.name}Serializer"
+                                                    definitionFile = "$errorSymbol.kt"
+                                                    name = exceptionName
+                                                    namespace = ctx.settings.pkg.serde
+                                                    reference(errorSymbol, SymbolReference.ContextOption.DECLARE)
+                                                }
+                                                write("is #T -> Pair(#T().serialize(#T(), errorObj), ${errorShape.getTrait<HttpErrorTrait>()?.code})", errorSymbol, exceptionSymbol, RuntimeTypes.Core.ExecutionContext)
+                                            }
+                                            write("else -> null")
+                                        }
+                                        write("if (errorResponse == null) throw t")
+
+                                        write("call.attributes.put(#T, true)", ServiceTypes(pkgName).responseHandledKey)
+                                        withBlock("when (errorObj) {", "}") {
+                                            shape.errors.forEach { errorShapeId ->
+                                                val errorShape = ctx.model.expectShape(errorShapeId)
+                                                val errorSymbol = ctx.symbolProvider.toSymbol(errorShape)
+                                                withBlock("is #T -> {", "}", errorSymbol) {
+                                                    readResponseHttpHeader("errorObj", errorShapeId, writer)
+                                                    readResponseHttpPrefixHeader("errorObj", errorShapeId, writer)
+                                                }
+                                            }
+                                            write("else -> null")
+                                        }
+                                        call { renderResponseCall("errorResponse.first", writer, acceptType, "\"\${errorResponse.second}\"", shape.output.get()) }
+                                    }
+                                }
+                            }
+                        }
+                    }
+            }
+        }
+    }
+}
+
+/**
+ * Reads `HttpLabelTrait` annotated members from request URI parameters
+ * and casts them to appropriate Kotlin types before populating request object.
+ */
+private fun KtorStubGenerator.readHttpLabel(shape: OperationShape, writer: KotlinWriter) {
+    val inputShape = ctx.model.expectShape(shape.input.get())
+    inputShape.allMembers
+        .filter { member -> member.value.hasTrait(HttpLabelTrait.ID) }
+        .forEach { member ->
+            val memberName = member.key
+            val memberShape = member.value
+
+            val httpLabelVariableName = "call.parameters[\"$memberName\"]?"
+            val targetShape = ctx.model.expectShape(memberShape.target)
+            writer.writeInline("$memberName = ")
+                .call {
+                    renderCastingPrimitiveFromShapeType(
+                        httpLabelVariableName,
+                        targetShape.type,
+                        writer,
+                        memberShape.getTrait<TimestampFormatTrait>() ?: inputShape.getTrait<TimestampFormatTrait>(),
+                        "Unsupported type ${memberShape.type} for httpLabel",
+                    )
+                }
+        }
+}
+
+/**
+ * Reads `HttpQueryTrait` and `HttpQueryParamsTrait` annotated members
+ * from query parameters. Handles both simple and list-valued query params,
+ * casting them to correct Kotlin types before populating request object.
+ */
+private fun KtorStubGenerator.readHttpQuery(shape: OperationShape, writer: KotlinWriter) {
+    val inputShape = ctx.model.expectShape(shape.input.get())
+    val httpQueryKeys = mutableSetOf<String>()
+    inputShape.allMembers
+        .filter { member -> member.value.hasTrait(HttpQueryTrait.ID) }
+        .forEach { member ->
+            val memberName = member.key
+            val memberShape = member.value
+            val httpQueryTrait = memberShape.getTrait<HttpQueryTrait>()!!
+            val httpQueryVariableName = "call.request.queryParameters[\"${httpQueryTrait.value}\"]?"
+            val targetShape = ctx.model.expectShape(memberShape.target)
+            httpQueryKeys.add(httpQueryTrait.value)
+            writer.writeInline("$memberName = ")
+                .call {
+                    when {
+                        targetShape.isListShape -> {
+                            val listMemberShape = targetShape.allMembers.values.first()
+                            val listMemberTargetShapeId = ctx.model.expectShape(listMemberShape.target)
+                            val httpQueryListVariableName = "(call.request.queryParameters.getAll(\"${httpQueryTrait.value}\") " +
+                                "?: call.request.queryParameters.getAll(\"${httpQueryTrait.value}[]\") " +
+                                "?: emptyList())"
+                            writer.withBlock("$httpQueryListVariableName.mapNotNull{", "}") {
+                                renderCastingPrimitiveFromShapeType(
+                                    "it?",
+                                    listMemberTargetShapeId.type,
+                                    writer,
+                                    listMemberShape.getTrait<TimestampFormatTrait>() ?: targetShape.getTrait<TimestampFormatTrait>(),
+                                    "Unsupported type ${memberShape.type} for list in httpLabel",
+                                )
+                            }
+                        }
+                        else -> renderCastingPrimitiveFromShapeType(
+                            httpQueryVariableName,
+                            targetShape.type,
+                            writer,
+                            memberShape.getTrait<TimestampFormatTrait>() ?: inputShape.getTrait<TimestampFormatTrait>(),
+                            "Unsupported type ${memberShape.type} for httpQuery",
+                        )
+                    }
+                }
+        }
+    val httpQueryParamsMember = inputShape.allMembers.values.firstOrNull { it.hasTrait(HttpQueryParamsTrait.ID) }
+    httpQueryParamsMember?.apply {
+        val httpQueryParamsMemberName = httpQueryParamsMember.memberName
+        val httpQueryParamsMapShape = ctx.model.expectShape(httpQueryParamsMember.target) as MapShape
+        val httpQueryParamsMapValueTypeShape = ctx.model.expectShape(httpQueryParamsMapShape.value.target)
+        val httpQueryKeysLiteral = httpQueryKeys.joinToString(", ") { "\"$it\"" }
+        writer.withInlineBlock("$httpQueryParamsMemberName = call.request.queryParameters.entries().filter { (key, _) ->", "}") {
+            write("key !in setOf($httpQueryKeysLiteral)")
+        }
+            .withBlock(".associate { (key, values) ->", "}") {
+                if (httpQueryParamsMapValueTypeShape.isListShape) {
+                    write("key to values!!")
+                } else {
+                    write("key to values.first()")
+                }
+            }
+            .withBlock(".mapValues { (_, value) ->", "}") {
+                renderCastingPrimitiveFromShapeType(
+                    "value",
+                    httpQueryParamsMapValueTypeShape.type,
+                    writer,
+                    httpQueryParamsMapValueTypeShape.getTrait<TimestampFormatTrait>() ?: httpQueryParamsMapShape.getTrait<TimestampFormatTrait>(),
+                    "Unsupported type ${httpQueryParamsMapValueTypeShape.type} for httpQuery",
+                )
+            }
+    }
+}
+
+/**
+ * Configures authentication for a given operation shape.
+ * Determines available authentication strategies (Bearer, SigV4, SigV4A)
+ * at service and operation level and installs them in Ktor's `authenticate` block.
+ */
+private fun KtorStubGenerator.renderRoutingAuth(w: KotlinWriter, shape: OperationShape) {
+    val serviceAuthTrait = serviceShape.getTrait<AuthTrait>()
+    val hasServiceHttpBearerAuthTrait = serviceShape.hasTrait(HttpBearerAuthTrait.ID)
+    val hasServiceSigV4AuthTrait = serviceShape.hasTrait(SigV4Trait.ID)
+    val hasServiceSigV4AAuthTrait = serviceShape.hasTrait(SigV4ATrait.ID)
+    val authTrait = shape.getTrait<AuthTrait>()
+    val hasOperationBearerAuthTrait = authTrait?.valueSet?.contains(HttpBearerAuthTrait.ID) ?: true
+    val hasOperationSigV4AuthTrait = authTrait?.valueSet?.contains(SigV4Trait.ID) ?: true
+    val hasOperationSigV4AAuthTrait = authTrait?.valueSet?.contains(SigV4ATrait.ID) ?: true
+
+    val availableAuthTraitOrderedSet = authTrait?.valueSet ?: serviceAuthTrait?.valueSet ?: setOf<ShapeId>(HttpBearerAuthTrait.ID, SigV4Trait.ID, SigV4ATrait.ID)
+
+    val authList = mutableListOf<String>()
+    availableAuthTraitOrderedSet.forEach { authTraitId ->
+        when (authTraitId) {
+            HttpBearerAuthTrait.ID -> if (hasServiceHttpBearerAuthTrait && hasOperationBearerAuthTrait) authList.add("auth-bearer")
+            SigV4Trait.ID -> if (hasServiceSigV4AuthTrait && hasOperationSigV4AuthTrait) authList.add("aws-sigv4")
+            SigV4ATrait.ID -> if (hasServiceSigV4AAuthTrait && hasOperationSigV4AAuthTrait) authList.add("aws-sigv4a")
+        }
+    }
+    authList.ifEmpty { authList.add("no-auth") }
+
+    w.write(
+        "#T(#L, strategy = #T.FirstSuccessful) {",
+        RuntimeTypes.KtorServerAuth.authenticate,
+        authList.joinToString(", ") { "\"$it\"" },
+        RuntimeTypes.KtorServerAuth.AuthenticationStrategy,
+    )
+}
+
+/**
+ * Reads and appends HTTP headers from response object fields annotated
+ * with `HttpHeaderTrait` to the Ktor response.
+ */
+private fun KtorStubGenerator.readResponseHttpHeader(dataName: String, shapeId: ShapeId, writer: KotlinWriter) {
+    val shape = ctx.model.expectShape(shapeId)
+    shape.allMembers
+        .filter { member -> member.value.hasTrait(HttpHeaderTrait.ID) }
+        .forEach { member ->
+            val headerName = member.value.getTrait<HttpHeaderTrait>()!!.value
+            val memberName = member.key
+            writer.write("call.response.headers.append(#S, $dataName.$memberName.toString())", headerName)
+        }
+}
+
+/**
+ * Reads and appends HTTP prefix headers from response object fields annotated
+ * with `HttpPrefixHeadersTrait`. Dynamically appends prefixed headers with suffix values.
+ */
+private fun KtorStubGenerator.readResponseHttpPrefixHeader(dataName: String, shapeId: ShapeId, writer: KotlinWriter) {
+    val shape = ctx.model.expectShape(shapeId)
+    shape.allMembers
+        .filter { member -> member.value.hasTrait(HttpPrefixHeadersTrait.ID) }
+        .forEach { member ->
+            val prefixHeaderName = member.value.getTrait<HttpPrefixHeadersTrait>()!!.value
+            val memberName = member.key
+            writer.withBlock("for ((suffixHeader, headerValue) in $dataName?.$memberName ?: mapOf()) {", "}") {
+                writer.write("call.response.headers.append(#S, headerValue.toString())", "$prefixHeaderName\${suffixHeader}")
+            }
+        }
+}
+
+/**
+ * Writes the Ktor call to send the response back to the client.
+ *
+ * - Selects correct responder (`respondBytes` or `responseText`) based on content type.
+ * - Sets appropriate content type and HTTP status code.
+ * - Supports CBOR, JSON, text, binary, and dynamic media types.
+ */
+private fun KtorStubGenerator.renderResponseCall(
+    responseName: String,
+    w: KotlinWriter,
+    acceptType: MediaType,
+    successCode: String,
+    outputShapeId: ShapeId,
+) {
+    when (acceptType) {
+        MediaType.CBOR -> w.withBlock(
+            "#T.#T(",
+            ")",
+            RuntimeTypes.KtorServerCore.applicationCall,
+            RuntimeTypes.KtorServerRouting.responseRespondBytes,
+        ) {
+            write("bytes = $responseName as ByteArray,")
+            write("contentType = #T,", RuntimeTypes.KtorServerHttp.Cbor)
+            write(
+                "status = #T.fromValue($successCode.toInt()),",
+                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+            )
+        }
+        OCTET_STREAM -> w.withBlock(
+            "#T.#T(",
+            ")",
+            RuntimeTypes.KtorServerCore.applicationCall,
+            RuntimeTypes.KtorServerRouting.responseRespondBytes,
+        ) {
+            write("bytes = $responseName as ByteArray,")
+            write("contentType = #T,", RuntimeTypes.KtorServerHttp.OctetStream)
+            write(
+                "status = #T.fromValue($successCode.toInt()),",
+                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+            )
+        }
+        JSON -> w.withBlock(
+            "#T.#T(",
+            ")",
+            RuntimeTypes.KtorServerCore.applicationCall,
+            RuntimeTypes.KtorServerRouting.responseResponseText,
+        ) {
+            write("text = $responseName as String,")
+            write("contentType = #T,", RuntimeTypes.KtorServerHttp.Json)
+            write(
+                "status = #T.fromValue($successCode.toInt()),",
+                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+            )
+        }
+        PLAIN_TEXT -> w.withBlock(
+            "#T.#T(",
+            ")",
+            RuntimeTypes.KtorServerCore.applicationCall,
+            RuntimeTypes.KtorServerRouting.responseResponseText,
+        ) {
+            write("text = $responseName as String,")
+            write("contentType = #T,", RuntimeTypes.KtorServerHttp.PlainText)
+            write(
+                "status = #T.fromValue($successCode.toInt()),",
+                RuntimeTypes.KtorServerHttp.HttpStatusCode,
+            )
+        }
+        ANY -> {
+            val outputShape = ctx.model.expectShape(outputShapeId)
+            val mediaTraits = outputShape.allMembers.values.firstNotNullOf { it.getTrait<MediaTypeTrait>() }
+            w.withBlock(
+                "#T.#T(",
+                ")",
+                RuntimeTypes.KtorServerCore.applicationCall,
+                RuntimeTypes.KtorServerRouting.responseRespondBytes,
+            ) {
+                write("bytes = $responseName as ByteArray,")
+                write("contentType = #S,", mediaTraits.value)
+                write(
+                    "status = #T.fromValue($successCode.toInt()),",
+                    RuntimeTypes.KtorServerHttp.HttpStatusCode,
+                )
+            }
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/ServerFrameworkImplementation.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/ServerFrameworkImplementation.kt
new file mode 100644
index 0000000000..3a008d8601
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/ServerFrameworkImplementation.kt
@@ -0,0 +1,73 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.core.withInlineBlock
+import software.amazon.smithy.kotlin.codegen.lang.KotlinTypes
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+
+/**
+ * Writes the server framework implementation for the generated Ktor service.
+ *
+ * - Defines the `Application.module()` entry point for configuring the Ktor pipeline
+ *   (logging, body size limits, double receive, error handling, authentication, routing).
+ * - Generates a concrete `KtorServiceFramework` implementation of `ServiceFramework`
+ *   that manages lifecycle of the Ktor embedded server engine.
+ */
+internal fun KtorStubGenerator.writeServerFrameworkImplementation(writer: KotlinWriter) {
+    writer.withBlock("internal fun #T.module(): Unit {", "}", RuntimeTypes.KtorServerCore.Application) {
+        write("#T()", ServiceTypes(pkgName).configureLogging)
+        withBlock("#T(#T) {", "}", RuntimeTypes.KtorServerCore.install, RuntimeTypes.KtorServerBodyLimit.RequestBodyLimit) {
+            write("bodyLimit { #T.requestBodyLimit }", ServiceTypes(pkgName).serviceFrameworkConfig)
+        }
+        write("#T(#T)", RuntimeTypes.KtorServerCore.install, RuntimeTypes.KtorServerDoubleReceive.DoubleReceive)
+        write("#T()", ServiceTypes(pkgName).configureErrorHandling)
+        write("#T()", ServiceTypes(pkgName).configureAuthentication)
+        write("#T()", ServiceTypes(pkgName).configureRouting)
+    }
+        .write("")
+    writer.withBlock("internal class KtorServiceFramework() : ServiceFramework {", "}") {
+        write("private var engine: #T<*, *>? = null", RuntimeTypes.KtorServerCore.EmbeddedServerType)
+        write("")
+        write("private val engineFactory = #T.engine.toEngineFactory()", ServiceTypes(pkgName).serviceFrameworkConfig)
+
+        write("")
+        withBlock("override fun start() {", "}") {
+            withInlineBlock("engine = #T(", ")", RuntimeTypes.KtorServerCore.embeddedServer) {
+                write("engineFactory,")
+                withBlock("configure = {", "}") {
+                    withBlock("#T {", "}", RuntimeTypes.KtorServerCore.connector) {
+                        write("host = #S", "0.0.0.0")
+                        write("port = #T.port", ServiceTypes(pkgName).serviceFrameworkConfig)
+                    }
+                    withBlock("when (this) {", "}") {
+                        withBlock("is #T -> {", "}", RuntimeTypes.KtorServerNetty.Configuration) {
+                            write("requestReadTimeoutSeconds = #T.requestReadTimeoutSeconds", ServiceTypes(pkgName).serviceFrameworkConfig)
+                            write("responseWriteTimeoutSeconds = #T.responseWriteTimeoutSeconds", ServiceTypes(pkgName).serviceFrameworkConfig)
+                        }
+
+                        withBlock("is #T -> {", "}", RuntimeTypes.KtorServerCio.Configuration) {
+                            write("connectionIdleTimeoutSeconds = #T.requestReadTimeoutSeconds", ServiceTypes(pkgName).serviceFrameworkConfig)
+                        }
+
+                        withBlock("is #T -> {", "}", RuntimeTypes.KtorServerJettyJakarta.Configuration) {
+                            write(
+                                "idleTimeout = #T.requestReadTimeoutSeconds.#T",
+                                ServiceTypes(pkgName).serviceFrameworkConfig,
+                                KotlinTypes.Time.seconds,
+                            )
+                        }
+                    }
+                }
+            }
+            write("{ #T() }", ServiceTypes(pkgName).module)
+            write("engine?.apply { start(wait = true) }")
+        }
+        write("")
+        withBlock("final override fun close() {", "}") {
+            write("engine?.stop(#T.closeGracePeriodMillis, #T.closeTimeoutMillis)", ServiceTypes(pkgName).serviceFrameworkConfig, ServiceTypes(pkgName).serviceFrameworkConfig)
+            write("engine = null")
+        }
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Utils.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Utils.kt
new file mode 100644
index 0000000000..57a68f19f3
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/ktor/Utils.kt
@@ -0,0 +1,97 @@
+package software.amazon.smithy.kotlin.codegen.service.ktor
+
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.kotlin.codegen.core.withBlock
+import software.amazon.smithy.kotlin.codegen.service.ServiceTypes
+
+/**
+ * Entry point for generating utility files required by the Ktor server stub.
+ *
+ * Currently delegates to [renderLogging] to generate logging configuration.
+ */
+internal fun KtorStubGenerator.writeUtils() {
+    renderLogging()
+}
+
+/**
+ * Generates logging configuration for the generated Ktor service.
+ *
+ * - Creates a `Logging.kt` file with `configureLogging()` extension function for
+ *   the Ktor `Application`, setting up SLF4J/Logback integration.
+ * - Maps service log levels to SLF4J/Logback levels.
+ * - Configures Ktor's `CallLogging` plugin to log HTTP method, URI, and status.
+ * - Registers lifecycle log messages (`starting`, `started`, `stopping`, `stopped`).
+ * - Writes a default `logback.xml` file into `src/main/resources` to ensure
+ *   console logging is available out of the box.
+ */
+private fun KtorStubGenerator.renderLogging() {
+    delegator.useFileWriter("Logging.kt", "$pkgName.utils") { writer ->
+
+        writer.withBlock("internal fun #T.configureLogging() {", "}", RuntimeTypes.KtorServerCore.Application) {
+            withBlock(
+                "val slf4jLevel: #T? = when (#T.logLevel) {",
+                "}",
+                RuntimeTypes.KtorLoggingSlf4j.Level,
+                ServiceTypes(pkgName).serviceFrameworkConfig,
+            ) {
+                write("#T.INFO -> #T.INFO", ServiceTypes(pkgName).logLevel, RuntimeTypes.KtorLoggingSlf4j.Level)
+                write("#T.TRACE -> #T.TRACE", ServiceTypes(pkgName).logLevel, RuntimeTypes.KtorLoggingSlf4j.Level)
+                write("#T.DEBUG -> #T.DEBUG", ServiceTypes(pkgName).logLevel, RuntimeTypes.KtorLoggingSlf4j.Level)
+                write("#T.WARN -> #T.WARN", ServiceTypes(pkgName).logLevel, RuntimeTypes.KtorLoggingSlf4j.Level)
+                write("#T.ERROR -> #T.ERROR", ServiceTypes(pkgName).logLevel, RuntimeTypes.KtorLoggingSlf4j.Level)
+                write("#T.OFF -> null", ServiceTypes(pkgName).logLevel)
+            }
+            write("")
+            write("val logbackLevel = slf4jLevel?.let { #T.valueOf(it.name) } ?: #T.OFF", RuntimeTypes.KtorLoggingLogback.Level, RuntimeTypes.KtorLoggingLogback.Level)
+            write("")
+            write(
+                "(#T.getILoggerFactory() as #T).getLogger(#T).level = logbackLevel",
+                RuntimeTypes.KtorLoggingSlf4j.LoggerFactory,
+                RuntimeTypes.KtorLoggingLogback.LoggerContext,
+                RuntimeTypes.KtorLoggingSlf4j.ROOT_LOGGER_NAME,
+            )
+            write("")
+            withBlock("if (slf4jLevel != null) {", "}") {
+                withBlock("#T(#T) {", "}", RuntimeTypes.KtorServerCore.install, RuntimeTypes.KtorServerLogging.CallLogging) {
+                    write("level = slf4jLevel")
+                    withBlock("format { call ->", "}") {
+                        write("val status = call.response.status()")
+                        write("\"\${call.request.#T.value} \${call.request.#T} → \$status\"", RuntimeTypes.KtorServerRouting.requestHttpMethod, RuntimeTypes.KtorServerRouting.requestUri)
+                    }
+                }
+            }
+            write("val log = #T.getLogger(#S)", RuntimeTypes.KtorLoggingSlf4j.LoggerFactory, ctx.settings.pkg.name)
+
+            withBlock("monitor.subscribe(#T) {", "}", RuntimeTypes.KtorServerCore.ApplicationStarting) {
+                write("log.info(#S)", "Server is starting...")
+            }
+
+            withBlock("monitor.subscribe(#T) {", "}", RuntimeTypes.KtorServerCore.ApplicationStarted) {
+                write("log.info(#S)", "Server started – ready to accept requests.")
+            }
+
+            withBlock("monitor.subscribe(#T) {", "}", RuntimeTypes.KtorServerCore.ApplicationStopping) {
+                write("log.warn(#S)", "Server is stopping – waiting for in-flight requests...")
+            }
+
+            withBlock("monitor.subscribe(#T) {", "}", RuntimeTypes.KtorServerCore.ApplicationStopped) {
+                write("log.info(#S)", "Server stopped cleanly.")
+            }
+        }
+    }
+    val loggingWriter = LoggingWriter()
+    loggingWriter.withBlock("<configuration>", "</configuration>") {
+        withBlock("<appender name=#S class=#S>", "</appender>", "STDOUT", "ch.qos.logback.core.ConsoleAppender") {
+            withBlock("<encoder>", "</encoder>") {
+                withBlock("<pattern>", "</pattern>") {
+                    write("%d{yyyy-MM-dd'T'HH:mm:ss.SSSXXX} %-5level %logger{36} - %msg%n")
+                }
+            }
+        }
+        withBlock("<root>", "</root>") {
+            write("<appender-ref ref=#S/>", "STDOUT")
+        }
+    }
+    val contents = loggingWriter.toString()
+    fileManifest.writeFile("src/main/resources/logback.xml", contents)
+}
diff --git a/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/utils.kt b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/utils.kt
new file mode 100644
index 0000000000..22e40ee7a7
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/service/utils.kt
@@ -0,0 +1,43 @@
+package software.amazon.smithy.kotlin.codegen.service
+
+import software.amazon.smithy.kotlin.codegen.core.KotlinWriter
+import software.amazon.smithy.kotlin.codegen.core.RuntimeTypes
+import software.amazon.smithy.model.shapes.ShapeType
+import software.amazon.smithy.model.traits.TimestampFormatTrait
+
+/**
+ * Renders Kotlin code that casts a variable to the correct primitive type
+ * based on its Smithy [ShapeType].
+ */
+fun renderCastingPrimitiveFromShapeType(
+    variable: String,
+    type: ShapeType,
+    writer: KotlinWriter,
+    timestampFormatTrait: TimestampFormatTrait? = null,
+    errorMessage: String? = null,
+) {
+    when (type) {
+        ShapeType.BLOB -> writer.write("$variable.toByteArray()")
+        ShapeType.STRING -> writer.write("$variable.toString()")
+        ShapeType.BYTE -> writer.write("$variable.toByte()")
+        ShapeType.INTEGER -> writer.write("$variable.toInt()")
+        ShapeType.SHORT -> writer.write("$variable.toShort()")
+        ShapeType.LONG -> writer.write("$variable.toLong()")
+        ShapeType.FLOAT -> writer.write("$variable.toFloat()")
+        ShapeType.DOUBLE -> writer.write("$variable.toDouble()")
+        ShapeType.BIG_DECIMAL -> writer.write("$variable.toBigDecimal()")
+        ShapeType.BIG_INTEGER -> writer.write("$variable.toBigInteger()")
+        ShapeType.BOOLEAN -> writer.write("$variable.toBoolean()")
+        ShapeType.TIMESTAMP ->
+            when (timestampFormatTrait?.format) {
+                TimestampFormatTrait.Format.EPOCH_SECONDS ->
+                    writer.write("$variable.let{ #T.fromEpochSeconds(it) }", RuntimeTypes.Core.Instant)
+                TimestampFormatTrait.Format.DATE_TIME ->
+                    writer.write("$variable.let{ #T.fromIso8601(it) }", RuntimeTypes.Core.Instant)
+                TimestampFormatTrait.Format.HTTP_DATE ->
+                    writer.write("$variable.let{ #T.fromRfc5322(it) }", RuntimeTypes.Core.Instant)
+                else -> writer.write("$variable.let{ #T.fromEpochSeconds(it) }", RuntimeTypes.Core.Instant)
+            }
+        else -> throw IllegalStateException(errorMessage ?: "Unable to render casting primitive for $type")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
index 2de132c9fa..7910b25cc1 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/KotlinSettingsTest.kt
@@ -11,6 +11,7 @@ import org.junit.jupiter.params.provider.Arguments
 import org.junit.jupiter.params.provider.ArgumentsProvider
 import org.junit.jupiter.params.provider.ArgumentsSource
 import org.junit.jupiter.params.provider.CsvSource
+import org.junit.jupiter.params.support.ParameterDeclarations
 import software.amazon.smithy.codegen.core.CodegenException
 import software.amazon.smithy.kotlin.codegen.test.TestModelDefault
 import software.amazon.smithy.kotlin.codegen.test.toSmithyModel
@@ -392,7 +393,10 @@ class TestProtocolSelectionArgumentProvider : ArgumentsProvider {
         private const val NO_CBOR = "awsJson1_0, awsJson1_1, restJson1, restXml, awsQuery, ec2Query"
     }
 
-    override fun provideArguments(context: ExtensionContext?): Stream<out Arguments> = Stream.of(
+    override fun provideArguments(
+        parameters: ParameterDeclarations?,
+        context: ExtensionContext?,
+    ): Stream<out Arguments> = Stream.of(
         Arguments.of(
             ALL_PROTOCOLS,
             "rpcv2Cbor, awsJson1_0",
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
index 162f32ac92..a5fb28e902 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/core/KotlinDelegatorTest.kt
@@ -97,7 +97,9 @@ class KotlinDelegatorTest {
             Node.parse(configContents).expectObjectNode(),
         )
         val manifest = MockManifest()
-        val delegator = KotlinDelegator(settings, model, manifest, KotlinSymbolProvider(model, settings))
+        val symbolProvider = KotlinSymbolProvider(model, settings)
+        val ctx = GenerationContext(model, symbolProvider, settings, protocolGenerator = null)
+        val delegator = KotlinDelegator(ctx, manifest)
 
         val generatedSymbol = buildSymbol {
             name = "Foo"
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
index a2272852fe..6356d3fbf6 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ExceptionGeneratorTest.kt
@@ -241,7 +241,7 @@ class ExceptionGeneratorTest {
                     get() = listOf(SectionWriterBinding(ExceptionBaseClassGenerator.ExceptionBaseClassSection, exceptionSectionWriter))
 
                 private val exceptionSectionWriter = SectionWriter { writer, _ ->
-                    val ctx = writer.getContextValue(ExceptionBaseClassGenerator.ExceptionBaseClassSection.CodegenContext)
+                    val ctx = writer.getContextValue(CodegenContext.Key)
                     ServiceExceptionBaseClassGenerator(exceptionBaseClassSymbol).render(ctx, writer)
                 }
             }
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt
new file mode 100644
index 0000000000..d5e0a6e152
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/DefaultEndpointDiscovererGeneratorTest.kt
@@ -0,0 +1,78 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.build.MockManifest
+import software.amazon.smithy.kotlin.codegen.test.formatForTest
+import software.amazon.smithy.kotlin.codegen.test.newTestContext
+import software.amazon.smithy.kotlin.codegen.test.shouldContainOnlyOnceWithDiff
+import software.amazon.smithy.kotlin.codegen.test.toCodegenContext
+
+class DefaultEndpointDiscovererGeneratorTest {
+    private val renderedCodegen: String = run {
+        val model = model()
+        val testCtx = model.newTestContext()
+        val delegator = testCtx.generationCtx.delegator
+        val generator = DefaultEndpointDiscovererGenerator(testCtx.toCodegenContext(), delegator)
+        generator.render()
+
+        delegator.flushWriters()
+        val testManifest = delegator.fileManifest as MockManifest
+        testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/DefaultTestEndpointDiscoverer.kt")
+    }
+
+    @Test
+    fun testClass() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                /**
+                 * A class which looks up specific endpoints for Test calls via the `getEndpoints` API. These
+                 * unique endpoints are cached as appropriate to avoid unnecessary latency in subsequent calls.
+                 * @param cache An [ExpiringKeyedCache] implementation used to cache discovered hosts
+                 */
+                public class DefaultTestEndpointDiscoverer(public val cache: ExpiringKeyedCache<DiscoveryParams, Host> = PeriodicSweepCache(10.minutes)) : TestEndpointDiscoverer {
+            """.trimIndent(),
+        )
+    }
+
+    @Test
+    fun testAsEndpointResolver() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                override fun asEndpointResolver(client: TestClient, delegate: EndpointResolver): EndpointResolver = EndpointResolver { request ->
+                    if (client.config.endpointUrl == null) {
+                        val identity = request.identity
+                        require(identity is Credentials) { "Endpoint discovery requires AWS credentials" }
+                
+                        val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)
+                        request.context[DiscoveryParamsKey] = cacheKey
+                        val discoveredHost = cache.get(cacheKey) { discoverHost(client) }
+                
+                        val originalEndpoint = delegate.resolve(request)
+                        Endpoint(
+                            originalEndpoint.uri.copy { host = discoveredHost },
+                            originalEndpoint.headers,
+                            originalEndpoint.attributes,
+                        )
+                    } else {
+                        delegate.resolve(request)
+                    }
+                }
+            """.formatForTest(),
+        )
+    }
+
+    @Test
+    fun testInvalidate() {
+        renderedCodegen.shouldContainOnlyOnceWithDiff(
+            """
+                override public suspend fun invalidate(context: ExecutionContext) {
+                    context.getOrNull(DiscoveryParamsKey)?.let { cache.invalidate(it) }
+                }
+            """.formatForTest(),
+        )
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt
deleted file mode 100644
index 37b9e6a900..0000000000
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererGeneratorTest.kt
+++ /dev/null
@@ -1,153 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
-
-import org.junit.jupiter.api.Test
-import software.amazon.smithy.build.MockManifest
-import software.amazon.smithy.kotlin.codegen.test.*
-
-class EndpointDiscovererGeneratorTest {
-    @Test
-    fun testClass() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-            public class TestEndpointDiscoverer {
-                private val cache = ReadThroughCache<DiscoveryParams, Host>(10.minutes, Clock.System)
-            """.trimIndent(),
-        )
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                }
-                
-                private val discoveryParamsKey = AttributeKey<DiscoveryParams>("DiscoveryParams")
-                private data class DiscoveryParams(private val region: String?, private val identity: String)
-            """.trimIndent(),
-        )
-    }
-
-    @Test
-    fun testAsEndpointResolver() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                internal fun asEndpointResolver(client: TestClient, delegate: EndpointResolverAdapter) = EndpointResolver { request ->
-                    if (client.config.endpointUrl == null) {
-                        val identity = request.identity
-                        require(identity is Credentials) { "Endpoint discovery requires AWS credentials" }
-                
-                        val cacheKey = DiscoveryParams(client.config.region, identity.accessKeyId)
-                        request.context[discoveryParamsKey] = cacheKey
-                        val discoveredHost = cache.get(cacheKey) { discoverHost(client) }
-                
-                        val originalEndpoint = delegate.resolve(request)
-                        Endpoint(
-                            originalEndpoint.uri.copy { host = discoveredHost },
-                            originalEndpoint.headers,
-                            originalEndpoint.attributes,
-                        )
-                    } else {
-                        delegate.resolve(request)
-                    }
-                }
-            """.formatForTest(),
-        )
-    }
-
-    @Test
-    fun testDiscoverHost() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                private suspend fun discoverHost(client: TestClient): ExpiringValue<Host> =
-                    client.getEndpoints()
-                        .endpoints
-                        ?.map { ep -> ExpiringValue(
-                            Host.parse(ep.address!!),
-                            Instant.now() + ep.cachePeriodInMinutes.minutes,
-                        )}
-                        ?.firstOrNull()
-                        ?: throw EndpointProviderException("Unable to discover any endpoints when invoking getEndpoints!")
-            """.formatForTest(),
-        )
-    }
-
-    @Test
-    fun testInvalidate() {
-        val actual = render()
-
-        actual.shouldContainOnlyOnceWithDiff(
-            """
-                internal suspend fun invalidate(context: ExecutionContext) {
-                    context.getOrNull(discoveryParamsKey)?.let { cache.invalidate(it) }
-                }
-            """.formatForTest(),
-        )
-    }
-
-    private fun render(): String {
-        val model = model()
-        val testCtx = model.newTestContext()
-        val delegator = testCtx.generationCtx.delegator
-        val generator = EndpointDiscovererGenerator(testCtx.toCodegenContext(), delegator)
-        generator.render()
-
-        delegator.flushWriters()
-        val testManifest = delegator.fileManifest as MockManifest
-        return testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/TestEndpointDiscoverer.kt")
-    }
-
-    private fun model() =
-        """
-            namespace com.test
-
-            use aws.protocols#awsJson1_1
-            use aws.api#service
-            use aws.auth#sigv4
-
-            @service(sdkId: "test")
-            @sigv4(name: "test")
-            @awsJson1_1
-            @aws.api#clientEndpointDiscovery(
-                operation: GetEndpoints,
-                error: BadEndpointError
-            )
-            service Test {
-                version: "1.0.0",
-                operations: [GetEndpoints]
-            }
-            
-            @error("client")
-            @httpError(421)
-            structure BadEndpointError { }
-
-            @http(method: "GET", uri: "/endpoints")
-            operation GetEndpoints {
-                input: GetEndpointsInput
-                output: GetEndpointsOutput
-            }
-            
-            @input
-            structure GetEndpointsInput { }
-            
-            @output
-            structure GetEndpointsOutput {
-                Endpoints: Endpoints
-            }
-            
-            list Endpoints {
-                member: Endpoint
-            }
-            
-            structure Endpoint {
-                Address: String
-                CachePeriodInMinutes: Long
-            }
-        """.toSmithyModel()
-}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt
new file mode 100644
index 0000000000..998fc8e577
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscovererInterfaceGeneratorTest.kt
@@ -0,0 +1,75 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import org.junit.jupiter.api.Test
+import software.amazon.smithy.build.MockManifest
+import software.amazon.smithy.kotlin.codegen.test.formatForTest
+import software.amazon.smithy.kotlin.codegen.test.newTestContext
+import software.amazon.smithy.kotlin.codegen.test.shouldContainOnlyOnceWithDiff
+import software.amazon.smithy.kotlin.codegen.test.toCodegenContext
+
+class EndpointDiscovererInterfaceGeneratorTest {
+    @Test
+    fun testInterface() {
+        val actual = render()
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                /**
+                 * Represents the logic for automatically discovering endpoints for Test calls
+                 */
+                public interface TestEndpointDiscoverer {
+                    public fun asEndpointResolver(client: TestClient, delegate: EndpointResolver): EndpointResolver
+            """.trimIndent(),
+        )
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                public suspend fun invalidate(context: ExecutionContext)
+            """.trimIndent(),
+        )
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                }
+                
+                public data class DiscoveryParams(private val region: String?, private val identity: String)
+                public val DiscoveryParamsKey: AttributeKey<DiscoveryParams> = AttributeKey("DiscoveryParams")
+            """.trimIndent(),
+        )
+    }
+
+    @Test
+    fun testDiscoverHost() {
+        val actual = render()
+
+        actual.shouldContainOnlyOnceWithDiff(
+            """
+                public suspend fun discoverHost(client: TestClient): ExpiringValue<Host> =
+                    client.getEndpoints()
+                        .endpoints
+                        ?.map { ep -> ExpiringValue(
+                            Host.parse(ep.address!!),
+                            Instant.now() + ep.cachePeriodInMinutes.minutes,
+                        )}
+                        ?.firstOrNull()
+                        ?: throw EndpointProviderException("Unable to discover any endpoints when invoking getEndpoints!")
+            """.formatForTest(),
+        )
+    }
+
+    private fun render(): String {
+        val model = model()
+        val testCtx = model.newTestContext()
+        val delegator = testCtx.generationCtx.delegator
+        val generator = EndpointDiscovererInterfaceGenerator(testCtx.toCodegenContext(), delegator)
+        generator.render()
+
+        delegator.flushWriters()
+        val testManifest = delegator.fileManifest as MockManifest
+        return testManifest.expectFileString("/src/main/kotlin/com/test/endpoints/TestEndpointDiscoverer.kt")
+    }
+}
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
index 48fec68de5..1fdb3f3973 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryIntegrationTest.kt
@@ -36,7 +36,7 @@ class EndpointDiscoveryIntegrationTest {
         val contents = writer.toString()
 
         if (discoveryRequired) {
-            val configStr = "public val endpointDiscoverer: TestEndpointDiscoverer = builder.endpointDiscoverer ?: TestEndpointDiscoverer()"
+            val configStr = "public val endpointDiscoverer: TestEndpointDiscoverer = builder.endpointDiscoverer ?: DefaultTestEndpointDiscoverer()"
             contents.shouldContainOnlyOnceWithDiff(configStr)
 
             val builderStr = """
@@ -52,9 +52,8 @@ class EndpointDiscoveryIntegrationTest {
 
             val builderStr = """
                 /**
-                 * The endpoint discoverer for this client, if applicable. By default, no endpoint
-                 * discovery is provided. To use endpoint discovery, set this to a valid
-                 * [TestEndpointDiscoverer] instance.
+                 * The endpoint discoverer for this client, if applicable. By default, no endpoint discovery is
+                 * provided. To use endpoint discovery, set this to a valid [TestEndpointDiscoverer] instance.
                  */
                 public var endpointDiscoverer: TestEndpointDiscoverer? = null
             """.formatForTest("        ")
@@ -62,6 +61,23 @@ class EndpointDiscoveryIntegrationTest {
         }
     }
 
+    @Test
+    fun testDiscoveredEndpointErrorMiddleware() {
+        val model = model()
+        val ctx = model.newTestContext(integrations = listOf(EndpointDiscoveryIntegration()))
+        val generator = MockHttpProtocolGenerator(model)
+        generator.generateProtocolClient(ctx.generationCtx)
+
+        ctx.generationCtx.delegator.finalize()
+        ctx.generationCtx.delegator.flushWriters()
+
+        val actual = ctx.manifest.expectFileString("/src/main/kotlin/com/test/DefaultTestClient.kt")
+
+        val getFooMethod = actual.lines("    override suspend fun getFoo(input: GetFooRequest): GetFooResponse {", "    }")
+        val expectedInterceptor = "config.endpointDiscoverer?.let { op.interceptors.add(DiscoveredEndpointErrorInterceptor(BadEndpointError::class, it::invalidate)) }"
+        getFooMethod.shouldContainOnlyOnceWithDiff(expectedInterceptor)
+    }
+
     private fun model(discoveryRequired: Boolean = true) =
         """
             namespace com.test
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt
new file mode 100644
index 0000000000..55d58d6cc4
--- /dev/null
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/endpoints/discovery/EndpointDiscoveryTestUtils.kt
@@ -0,0 +1,56 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package software.amazon.smithy.kotlin.codegen.rendering.endpoints.discovery
+
+import software.amazon.smithy.kotlin.codegen.test.toSmithyModel
+
+fun model() =
+    // language=smithy
+    """
+        namespace com.test
+        
+        use aws.protocols#awsJson1_1
+        use aws.api#service
+        use aws.auth#sigv4
+        
+        @service(sdkId: "test")
+        @sigv4(name: "test")
+        @awsJson1_1
+        @aws.api#clientEndpointDiscovery(
+            operation: GetEndpoints,
+            error: BadEndpointError
+        )
+        service Test {
+            version: "1.0.0",
+            operations: [GetEndpoints]
+        }
+        
+        @error("client")
+        @httpError(421)
+        structure BadEndpointError { }
+        
+        @http(method: "GET", uri: "/endpoints")
+        operation GetEndpoints {
+            input: GetEndpointsInput
+            output: GetEndpointsOutput
+        }
+        
+        @input
+        structure GetEndpointsInput { }
+        
+        @output
+        structure GetEndpointsOutput {
+            Endpoints: Endpoints
+        }
+        
+        list Endpoints {
+            member: Endpoint
+        }
+        
+        structure Endpoint {
+            Address: String
+            CachePeriodInMinutes: Long
+        }
+    """.toSmithyModel()
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
index 95138ad529..097db4b4c8 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/protocol/HttpStringValuesMapSerializerTest.kt
@@ -53,7 +53,8 @@ class HttpStringValuesMapSerializerTest {
 
     @Test
     fun `it handles primitive header shapes when different mode`() {
-        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.HEADER)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.HEADER, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
@@ -68,7 +69,8 @@ class HttpStringValuesMapSerializerTest {
 
     @Test
     fun `it handles primitive query shapes when different mode`() {
-        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.QUERY)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(defaultModel, "com.test#PrimitiveShapesOperation", HttpBinding.Location.QUERY, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
@@ -129,7 +131,8 @@ class HttpStringValuesMapSerializerTest {
             }
         """.prependNamespaceAndService(operations = listOf("Foo")).toSmithyModel()
 
-        val contents = getTestContents(model, "com.test#Foo", HttpBinding.Location.HEADER)
+        val settings = defaultModel.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val contents = getTestContents(model, "com.test#Foo", HttpBinding.Location.HEADER, settings)
         contents.assertBalancedBracesAndParens()
 
         val expectedContents = """
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
index 347da007cb..c0eae1f05b 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/serde/SerializeStructGeneratorTest.kt
@@ -72,7 +72,8 @@ class SerializeStructGeneratorTest {
             }
         """.trimIndent()
 
-        val actual = codegenSerializerForShape(model, "com.test#Foo")
+        val settings = model.defaultSettings(defaultValueSerializationMode = DefaultValueSerializationMode.WHEN_DIFFERENT)
+        val actual = codegenSerializerForShape(model, "com.test#Foo", settings = settings)
         actual.shouldContainOnlyOnceWithDiff(expected)
     }
 
diff --git a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
index 49ee90f484..038a2ff7da 100644
--- a/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
+++ b/codegen/smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/waiters/ServiceWaitersGeneratorTest.kt
@@ -11,13 +11,10 @@ import software.amazon.smithy.build.MockManifest
 import software.amazon.smithy.codegen.core.SymbolProvider
 import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
-import software.amazon.smithy.kotlin.codegen.core.CodegenContext
+import software.amazon.smithy.kotlin.codegen.core.GenerationContext
 import software.amazon.smithy.kotlin.codegen.core.KotlinDelegator
-import software.amazon.smithy.kotlin.codegen.integration.KotlinIntegration
 import software.amazon.smithy.kotlin.codegen.loadModelFromResource
-import software.amazon.smithy.kotlin.codegen.rendering.protocol.ProtocolGenerator
 import software.amazon.smithy.kotlin.codegen.test.*
-import software.amazon.smithy.model.Model
 import software.amazon.smithy.model.shapes.ShapeId
 import kotlin.test.Test
 import kotlin.test.assertEquals
@@ -130,16 +127,9 @@ class ServiceWaitersGeneratorTest {
         val service = model.getShape(ShapeId.from(TestModelDefault.SERVICE_SHAPE_ID)).get().asServiceShape().get()
         val settings = KotlinSettings(service.id, KotlinSettings.PackageSettings(TestModelDefault.NAMESPACE, TestModelDefault.MODEL_VERSION), sdkId = service.id.name)
 
-        val ctx = object : CodegenContext {
-            override val model: Model = model
-            override val symbolProvider: SymbolProvider = provider
-            override val settings: KotlinSettings = settings
-            override val protocolGenerator: ProtocolGenerator? = null
-            override val integrations: List<KotlinIntegration> = listOf()
-        }
-
         val manifest = MockManifest()
-        val delegator = KotlinDelegator(settings, model, manifest, provider)
+        val ctx = GenerationContext(model, provider, settings, protocolGenerator = null)
+        val delegator = KotlinDelegator(ctx, manifest)
 
         val generator = ServiceWaitersGenerator()
         generator.writeAdditionalFiles(ctx, delegator)
diff --git a/examples/service-codegen/build.bat b/examples/service-codegen/build.bat
new file mode 100644
index 0000000000..2141f3f940
--- /dev/null
+++ b/examples/service-codegen/build.bat
@@ -0,0 +1,13 @@
+@echo off
+if exist build (
+    set /p choice="The 'build' directory already exists. Removing it will delete previous build artifacts. Continue? (y/n): "
+    if /i "%choice%"=="y" (
+        gradle clean
+        echo Previous build directory removed.
+    ) else (
+        echo Aborted.
+        exit /b 1
+    )
+)
+
+gradle build
diff --git a/examples/service-codegen/build.gradle.kts b/examples/service-codegen/build.gradle.kts
new file mode 100644
index 0000000000..28003a6fef
--- /dev/null
+++ b/examples/service-codegen/build.gradle.kts
@@ -0,0 +1,54 @@
+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * This generated file contains a sample Kotlin application project to get you started.
+ * For more details on building Java & JVM projects, please refer to https://docs.gradle.org/8.14.2/userguide/building_java_projects.html in the Gradle documentation.
+ */
+
+plugins {
+    // Apply the org.jetbrains.kotlin.jvm Plugin to add support for Kotlin.
+    alias(libs.plugins.kotlin.jvm)
+
+    id("software.amazon.smithy.gradle.smithy-jar") version "1.3.0"
+    // Apply the application plugin to add support for building a CLI application in Java.
+    application
+}
+
+repositories {
+    // Use Maven Central for resolving dependencies.
+    mavenCentral()
+    mavenLocal()
+}
+
+val codegenVersion = "0.35.2-SNAPSHOT"
+val smithyVersion = "1.60.2"
+
+dependencies {
+    smithyBuild("software.amazon.smithy.kotlin:smithy-kotlin-codegen:$codegenVersion")
+    implementation("software.amazon.smithy.kotlin:smithy-aws-kotlin-codegen:$codegenVersion")
+    implementation("software.amazon.smithy:smithy-model:$smithyVersion")
+    implementation("software.amazon.smithy:smithy-build:$smithyVersion")
+    implementation("software.amazon.smithy:smithy-aws-traits:$smithyVersion")
+    // Use the Kotlin JUnit 5 integration.
+    testImplementation("org.jetbrains.kotlin:kotlin-test-junit5")
+
+    // Use the JUnit 5 integration.
+    testImplementation(libs.junit.jupiter.engine)
+
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+
+    // This dependency is used by the application.
+    implementation(libs.guava)
+}
+
+// Apply a specific Java toolchain to ease working on different environments.
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(21)
+    }
+}
+
+tasks.named<Test>("test") {
+    // Use JUnit Platform for unit tests.
+    useJUnitPlatform()
+}
diff --git a/examples/service-codegen/build.sh b/examples/service-codegen/build.sh
new file mode 100644
index 0000000000..dc22c98a9c
--- /dev/null
+++ b/examples/service-codegen/build.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+if [ -d "build" ]; then
+    read -p "The 'build' directory already exists. Removing it will delete previous build artifacts. Continue? (y/n): " choice
+    case "$choice" in
+        y|Y )
+            gradle clean
+            echo "Previous build directory removed."
+            ;;
+        * )
+            echo "Aborted."
+            exit 1
+            ;;
+    esac
+fi
+
+gradle build
diff --git a/examples/service-codegen/model/demo.smithy b/examples/service-codegen/model/demo.smithy
new file mode 100644
index 0000000000..b887aa4e2c
--- /dev/null
+++ b/examples/service-codegen/model/demo.smithy
@@ -0,0 +1,49 @@
+// model/greeter.smithy
+$version: "2.0"
+
+namespace com.demo
+
+use aws.protocols#restJson1
+use smithy.api#httpBearerAuth
+
+@restJson1
+@httpBearerAuth
+service DemoService {
+    version: "1.0.0"
+    operations: [
+        SayHello
+    ]
+}
+
+@http(method: "POST", uri: "/greet", code: 201)
+operation SayHello {
+    input: SayHelloInput
+    output: SayHelloOutput
+    errors: [
+        CustomError
+    ]
+}
+
+@input
+structure SayHelloInput {
+    @required
+    @length(min: 3, max: 10)
+    name: String
+
+    @httpHeader("X-User-ID")
+    id: Integer
+}
+
+@output
+structure SayHelloOutput {
+    greeting: String
+}
+
+@error("server")
+@httpError(500)
+structure CustomError {
+    msg: String
+
+    @httpHeader("X-User-error")
+    err: String
+}
diff --git a/examples/service-codegen/smithy-build.json b/examples/service-codegen/smithy-build.json
new file mode 100644
index 0000000000..7b1948b71c
--- /dev/null
+++ b/examples/service-codegen/smithy-build.json
@@ -0,0 +1,30 @@
+{
+  "version": "1.0",
+  "outputDirectory": "build/generated-src-test",
+  "plugins": {
+    "kotlin-codegen": {
+      "service": "com.demo#DemoService",
+
+      "package": {
+        "name": "com.demo.server",
+        "version": "1.0.0"
+      },
+
+      "build": {
+        "rootProject": true,
+        "generateServiceProject": true,
+        "optInAnnotations": [
+          "aws.smithy.kotlin.runtime.InternalApi",
+          "kotlinx.serialization.ExperimentalSerializationApi"
+        ]
+      },
+
+      "serviceStub": {
+        "framework": "ktor"
+      }
+    }
+  }
+}
+
+
+
diff --git a/gradle.properties b/gradle.properties
index aa80c53d95..9bb3537255 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -13,10 +13,10 @@ kotlinx.atomicfu.enableNativeIrTransformation=false
 org.gradle.jvmargs=-Xmx2G -XX:MaxMetaspaceSize=1G
 
 # SDK
-sdkVersion=1.4.24-SNAPSHOT
+sdkVersion=1.5.2-SNAPSHOT
 
 # codegen
-codegenVersion=0.34.24-SNAPSHOT
+codegenVersion=0.35.2-SNAPSHOT
 
 # FIXME Remove after Dokka 2.0 Gradle plugin is stable
 org.jetbrains.dokka.experimental.gradle.pluginMode=V2Enabled
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 94f31d2cbc..edfc411abf 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,33 +1,33 @@
 [versions]
-kotlin-version = "2.1.0"
+kotlin-version = "2.2.0"
 dokka-version = "2.0.0"
 
 aws-kotlin-repo-tools-version = "0.4.32"
 
 # libs
-coroutines-version = "1.9.0"
-atomicfu-version = "0.25.0"
-okhttp-version = "5.0.0-alpha.14"
+coroutines-version = "1.10.2"
+atomicfu-version = "0.29.0"
+okhttp-version = "5.1.0"
 okhttp4-version = "4.12.0"
-okio-version = "3.9.1"
+okio-version = "3.15.0"
 otel-version = "1.45.0"
 slf4j-version = "2.0.16"
 slf4j-v1x-version = "1.7.36"
-crt-kotlin-version = "0.9.1"
+crt-kotlin-version = "0.10.0"
 micrometer-version = "1.14.2"
-binary-compatibility-validator-version = "0.16.3"
+binary-compatibility-validator-version = "0.18.0"
 
 # codegen
 smithy-version = "1.60.2"
 
 # testing
-junit-version = "5.10.5"
+junit-version = "5.13.2"
 kotest-version = "5.9.1"
 kotlin-compile-testing-version = "0.7.0"
 kotlinx-benchmark-version = "0.4.12"
 kotlinx-serialization-version = "1.7.3"
 docker-java-version = "3.4.0"
-ktor-version = "3.1.1"
+ktor-version = "3.2.2"
 kaml-version = "0.55.0"
 jsoup-version = "1.19.1"
 
@@ -88,6 +88,7 @@ kotest-assertions-core = { module = "io.kotest:kotest-assertions-core", version.
 kotest-assertions-core-jvm = { module = "io.kotest:kotest-assertions-core-jvm", version.ref = "kotest-version" }
 kotlinx-benchmark-runtime = { module = "org.jetbrains.kotlinx:kotlinx-benchmark-runtime", version.ref = "kotlinx-benchmark-version" }
 kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinx-serialization-version" }
+kotlinx-serialization-cbor = { module = "org.jetbrains.kotlinx:kotlinx-serialization-cbor", version.ref = "kotlinx-serialization-version" }
 docker-core = { module = "com.github.docker-java:docker-java-core", version.ref = "docker-java-version" }
 docker-transport-zerodep = { module = "com.github.docker-java:docker-java-transport-zerodep", version.ref = "docker-java-version" }
 
diff --git a/runtime/auth/aws-credentials/api/aws-credentials.api b/runtime/auth/aws-credentials/api/aws-credentials.api
index 15df96aff6..429f5eec3b 100644
--- a/runtime/auth/aws-credentials/api/aws-credentials.api
+++ b/runtime/auth/aws-credentials/api/aws-credentials.api
@@ -18,9 +18,9 @@ public abstract interface class aws/smithy/kotlin/runtime/auth/awscredentials/Cl
 public abstract interface class aws/smithy/kotlin/runtime/auth/awscredentials/Credentials : aws/smithy/kotlin/runtime/identity/Identity {
 	public static final field Companion Laws/smithy/kotlin/runtime/auth/awscredentials/Credentials$Companion;
 	public abstract fun getAccessKeyId ()Ljava/lang/String;
-	public abstract fun getProviderName ()Ljava/lang/String;
+	public fun getProviderName ()Ljava/lang/String;
 	public abstract fun getSecretAccessKey ()Ljava/lang/String;
-	public abstract fun getSessionToken ()Ljava/lang/String;
+	public fun getSessionToken ()Ljava/lang/String;
 }
 
 public final class aws/smithy/kotlin/runtime/auth/awscredentials/Credentials$Companion {
diff --git a/runtime/auth/aws-signing-common/api/aws-signing-common.api b/runtime/auth/aws-signing-common/api/aws-signing-common.api
index c9353509be..046afa8c53 100644
--- a/runtime/auth/aws-signing-common/api/aws-signing-common.api
+++ b/runtime/auth/aws-signing-common/api/aws-signing-common.api
@@ -199,13 +199,6 @@ public final class aws/smithy/kotlin/runtime/auth/awssigning/PresignerKt {
 	public static final fun presignRequest (Laws/smithy/kotlin/runtime/http/request/HttpRequestBuilder;Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/auth/awscredentials/CredentialsProvider;Laws/smithy/kotlin/runtime/http/operation/EndpointResolver;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigner;Lkotlin/jvm/functions/Function1;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public final class aws/smithy/kotlin/runtime/auth/awssigning/UnsupportedSigningAlgorithmException : aws/smithy/kotlin/runtime/ClientException {
-	public fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;)V
-	public fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;Ljava/lang/Throwable;)V
-	public synthetic fun <init> (Ljava/lang/String;Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;Ljava/lang/Throwable;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public final fun getSigningAlgorithm ()Laws/smithy/kotlin/runtime/auth/awssigning/AwsSigningAlgorithm;
-}
-
 public final class aws/smithy/kotlin/runtime/auth/awssigning/internal/AwsChunkedUtilKt {
 	public static final field AWS_CHUNKED_THRESHOLD I
 	public static final field CHUNK_SIZE_BYTES I
diff --git a/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt b/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt
deleted file mode 100644
index 8ff8c1e35f..0000000000
--- a/runtime/auth/aws-signing-common/common/src/aws/smithy/kotlin/runtime/auth/awssigning/AwsSigningExceptions.kt
+++ /dev/null
@@ -1,37 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-package aws.smithy.kotlin.runtime.auth.awssigning
-
-import aws.smithy.kotlin.runtime.ClientException
-import aws.smithy.kotlin.runtime.InternalApi
-
-/**
- * Is thrown when a signing algorithm is not supported by a signer
- *
- * See: [AwsSigningAlgorithm], [AwsSigner]
- *
- * @param message The message displayed by the exception
- * @param signingAlgorithm The unsupported signing algorithm
- * @param cause The cause of the exception
- */
-@InternalApi
-@Deprecated("This exception is no longer thrown. It will be removed in the next minor version, v1.5.x.")
-public class UnsupportedSigningAlgorithmException(
-    message: String,
-    public val signingAlgorithm: AwsSigningAlgorithm,
-    cause: Throwable? = null,
-) : ClientException(
-    message,
-    cause,
-) {
-    public constructor(
-        message: String,
-        signingAlgorithm: AwsSigningAlgorithm,
-    ) : this (
-        message,
-        signingAlgorithm,
-        null,
-    )
-}
diff --git a/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt b/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
index 4f4239a2ce..c4fe4f5ca4 100644
--- a/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
+++ b/runtime/auth/aws-signing-default/common/src/aws/smithy/kotlin/runtime/auth/awssigning/SigV4aSignatureCalculator.kt
@@ -5,7 +5,7 @@
 package aws.smithy.kotlin.runtime.auth.awssigning
 
 import aws.smithy.kotlin.runtime.auth.awscredentials.Credentials
-import aws.smithy.kotlin.runtime.collections.ReadThroughCache
+import aws.smithy.kotlin.runtime.collections.PeriodicSweepCache
 import aws.smithy.kotlin.runtime.content.BigInteger
 import aws.smithy.kotlin.runtime.hashing.HashSupplier
 import aws.smithy.kotlin.runtime.hashing.Sha256
@@ -32,7 +32,7 @@ internal val N_MINUS_TWO = "FFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9
  * @param sha256Provider the [HashSupplier] to use for computing SHA-256 hashes
  */
 internal class SigV4aSignatureCalculator(override val sha256Provider: HashSupplier = ::Sha256) : BaseSigV4SignatureCalculator(AwsSigningAlgorithm.SIGV4_ASYMMETRIC, sha256Provider) {
-    private val privateKeyCache = ReadThroughCache<Credentials, ByteArray>(
+    private val privateKeyCache = PeriodicSweepCache<Credentials, ByteArray>(
         minimumSweepPeriod = 1.hours, // note: Sweeps are effectively a no-op because expiration is [Instant.MAX_VALUE]
     )
 
diff --git a/runtime/auth/aws-signing-tests/build.gradle.kts b/runtime/auth/aws-signing-tests/build.gradle.kts
index 5810181041..667021303e 100644
--- a/runtime/auth/aws-signing-tests/build.gradle.kts
+++ b/runtime/auth/aws-signing-tests/build.gradle.kts
@@ -17,7 +17,6 @@ kotlin {
                 api(project(":runtime:auth:http-auth-aws"))
                 implementation(libs.kotlin.test)
                 implementation(libs.kotlinx.coroutines.test)
-                implementation(libs.junit.jupiter.params)
             }
         }
 
@@ -28,6 +27,7 @@ kotlin {
                 implementation(libs.ktor.http.cio)
                 implementation(libs.ktor.utils)
                 implementation(libs.kotlin.test.junit5)
+                implementation(libs.junit.jupiter.params)
                 implementation(libs.kotlinx.serialization.json)
             }
         }
diff --git a/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt b/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
index b3c4202d26..70d48bfe45 100644
--- a/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
+++ b/runtime/auth/aws-signing-tests/jvm/src/aws/smithy/kotlin/runtime/auth/awssigning/tests/SigningSuiteTestBaseJVM.kt
@@ -11,7 +11,9 @@ import aws.smithy.kotlin.runtime.auth.awssigning.*
 import aws.smithy.kotlin.runtime.collections.Attributes
 import aws.smithy.kotlin.runtime.collections.ValuesMap
 import aws.smithy.kotlin.runtime.collections.get
-import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.HttpBody
+import aws.smithy.kotlin.runtime.http.HttpMethod
+import aws.smithy.kotlin.runtime.http.SdkHttpClient
 import aws.smithy.kotlin.runtime.http.auth.AwsHttpSigner
 import aws.smithy.kotlin.runtime.http.auth.SigV4AuthScheme
 import aws.smithy.kotlin.runtime.http.operation.*
@@ -24,9 +26,7 @@ import aws.smithy.kotlin.runtime.net.url.Url
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import aws.smithy.kotlin.runtime.time.Instant
 import io.ktor.http.cio.*
-import io.ktor.util.*
 import io.ktor.utils.io.*
-import io.ktor.utils.io.core.*
 import kotlinx.coroutines.runBlocking
 import kotlinx.io.readByteArray
 import kotlinx.serialization.json.*
@@ -420,8 +420,7 @@ private fun buildOperation(
         serializeWith = object : HttpSerializer.NonStreaming<Unit> {
             override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder = serialized
         }
-        @Suppress("DEPRECATION")
-        deserializer = IdentityDeserializer
+        deserializeWith = HttpDeserializer.Identity
 
         context {
             operationName = "testSigningOperation"
diff --git a/runtime/auth/http-auth-api/api/http-auth-api.api b/runtime/auth/http-auth-api/api/http-auth-api.api
index 491aa48555..2f541fb6ef 100644
--- a/runtime/auth/http-auth-api/api/http-auth-api.api
+++ b/runtime/auth/http-auth-api/api/http-auth-api.api
@@ -1,7 +1,7 @@
 public abstract interface class aws/smithy/kotlin/runtime/http/auth/AuthScheme {
 	public abstract fun getSchemeId-DepwgT4 ()Ljava/lang/String;
 	public abstract fun getSigner ()Laws/smithy/kotlin/runtime/http/auth/HttpSigner;
-	public abstract fun identityProvider (Laws/smithy/kotlin/runtime/identity/IdentityProviderConfig;)Laws/smithy/kotlin/runtime/identity/IdentityProvider;
+	public fun identityProvider (Laws/smithy/kotlin/runtime/identity/IdentityProviderConfig;)Laws/smithy/kotlin/runtime/identity/IdentityProvider;
 }
 
 public final class aws/smithy/kotlin/runtime/http/auth/AuthScheme$DefaultImpls {
diff --git a/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt b/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
index 7d10b35e14..75be7cbbf2 100644
--- a/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
+++ b/runtime/auth/http-auth-aws/common/test/aws/smithy/kotlin/runtime/http/auth/AwsHttpSignerTestBase.kt
@@ -37,13 +37,11 @@ class DefaultAwsHttpSignerTest : AwsHttpSignerTestBase(DefaultAwsSigner)
  * Basic sanity tests. Signing (including `AwsHttpSigner`) is covered by the more exhaustive
  * test suite in the `aws-signing-tests` module.
  */
-@Suppress("HttpUrlsUsage")
 public abstract class AwsHttpSignerTestBase(
     private val signer: AwsSigner,
 ) {
     private val testCredentials = Credentials("AKID", "SECRET", "SESSION")
 
-    @Suppress("DEPRECATION")
     private fun buildOperation(
         requestBody: String = "{\"TableName\": \"foo\"}",
         streaming: Boolean = false,
@@ -51,29 +49,11 @@ public abstract class AwsHttpSignerTestBase(
         unsigned: Boolean = false,
     ): SdkHttpOperation<Unit, HttpResponse> {
         val operation: SdkHttpOperation<Unit, HttpResponse> = SdkHttpOperation.build {
-            serializer = object : HttpSerialize<Unit> {
-                override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
-                    HttpRequestBuilder().apply {
-                        method = HttpMethod.POST
-                        url.scheme = Scheme.HTTP
-                        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
-                        url.path.encoded = "/"
-                        headers.append("Host", "demo.us-east-1.amazonaws.com")
-                        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
-                        body = when (streaming) {
-                            true -> {
-                                object : HttpBody.ChannelContent() {
-                                    override val contentLength: Long = requestBody.length.toLong()
-                                    override fun readFrom(): SdkByteReadChannel = SdkByteReadChannel(requestBody.encodeToByteArray())
-                                    override val isOneShot: Boolean = !replayable
-                                }
-                            }
-                            false -> HttpBody.fromBytes(requestBody.encodeToByteArray())
-                        }
-                        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
-                    }
+            serializeWith = when (streaming) {
+                true -> StreamingSerializer(requestBody, replayable)
+                false -> NonStreamingSerializer(requestBody)
             }
-            deserializer = IdentityDeserializer
+            deserializeWith = HttpDeserializer.Identity
             operationName = "testSigningOperation"
             serviceName = "testService"
             context {
@@ -186,3 +166,36 @@ public abstract class AwsHttpSignerTestBase(
         assertEquals(expectedSig, signed.headers["Authorization"])
     }
 }
+
+private class NonStreamingSerializer(private val requestBody: String) : HttpSerializer.NonStreaming<Unit> {
+    override fun serialize(context: ExecutionContext, input: Unit) = HttpRequestBuilder().apply {
+        method = HttpMethod.POST
+        url.scheme = Scheme.HTTP
+        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
+        url.path.encoded = "/"
+        body = HttpBody.fromBytes(requestBody.encodeToByteArray())
+        headers.append("Host", "demo.us-east-1.amazonaws.com")
+        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
+        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
+    }
+}
+
+private class StreamingSerializer(
+    private val requestBody: String,
+    private val replayable: Boolean,
+) : HttpSerializer.Streaming<Unit> {
+    override suspend fun serialize(context: ExecutionContext, input: Unit) = HttpRequestBuilder().apply {
+        method = HttpMethod.POST
+        url.scheme = Scheme.HTTP
+        url.host = Host.Domain("demo.us-east-1.amazonaws.com")
+        url.path.encoded = "/"
+        body = object : HttpBody.ChannelContent() {
+            override val contentLength: Long = requestBody.length.toLong()
+            override fun readFrom(): SdkByteReadChannel = SdkByteReadChannel(requestBody.encodeToByteArray())
+            override val isOneShot: Boolean = !replayable
+        }
+        headers.append("Host", "demo.us-east-1.amazonaws.com")
+        headers.appendAll("x-amz-archive-description", listOf("test", "test"))
+        headers.append("Content-Length", body.contentLength?.toString() ?: "0")
+    }
+}
diff --git a/runtime/auth/identity-api/api/identity-api.api b/runtime/auth/identity-api/api/identity-api.api
index 9b07562934..824dc99385 100644
--- a/runtime/auth/identity-api/api/identity-api.api
+++ b/runtime/auth/identity-api/api/identity-api.api
@@ -56,6 +56,7 @@ public final class aws/smithy/kotlin/runtime/identity/IdentityAttributesKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/identity/IdentityProvider {
 	public abstract fun resolve (Laws/smithy/kotlin/runtime/collections/Attributes;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun resolve$default (Laws/smithy/kotlin/runtime/identity/IdentityProvider;Laws/smithy/kotlin/runtime/collections/Attributes;Lkotlin/coroutines/Continuation;ILjava/lang/Object;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/identity/IdentityProvider$DefaultImpls {
diff --git a/runtime/build.gradle.kts b/runtime/build.gradle.kts
index 4aa9e06b3b..9da74f02a8 100644
--- a/runtime/build.gradle.kts
+++ b/runtime/build.gradle.kts
@@ -69,6 +69,7 @@ subprojects {
             freeCompilerArgs.add("-Xexpect-actual-classes")
         }
     }
+
     tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinNativeCompile> {
         compilerOptions {
             freeCompilerArgs.add("-Xexpect-actual-classes")
diff --git a/runtime/observability/telemetry-api/api/telemetry-api.api b/runtime/observability/telemetry-api/api/telemetry-api.api
index 470061210b..5e1f6b8684 100644
--- a/runtime/observability/telemetry-api/api/telemetry-api.api
+++ b/runtime/observability/telemetry-api/api/telemetry-api.api
@@ -176,11 +176,16 @@ public abstract interface class aws/smithy/kotlin/runtime/telemetry/logging/Logg
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/logging/Logger$Companion;
 	public abstract fun atLevel (Laws/smithy/kotlin/runtime/telemetry/logging/LogLevel;)Laws/smithy/kotlin/runtime/telemetry/logging/LogRecordBuilder;
 	public abstract fun debug (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun debug$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun error (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun error$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun info (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun info$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun isEnabledFor (Laws/smithy/kotlin/runtime/telemetry/logging/LogLevel;)Z
 	public abstract fun trace (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun trace$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 	public abstract fun warn (Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;)V
+	public static synthetic fun warn$default (Laws/smithy/kotlin/runtime/telemetry/logging/Logger;Ljava/lang/Throwable;Lkotlin/jvm/functions/Function0;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/logging/Logger$Companion {
@@ -266,6 +271,7 @@ public abstract class aws/smithy/kotlin/runtime/telemetry/metrics/AbstractUpDown
 
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement {
 	public abstract fun record (Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun record$default (Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement;Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurement$DefaultImpls {
@@ -284,6 +290,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementH
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/Histogram {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram$Companion;
 	public abstract fun record (Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun record$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;Ljava/lang/Number;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/Histogram$Companion {
@@ -307,12 +314,19 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/HistogramKt {
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/Meter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/Meter$Companion;
 	public abstract fun createAsyncUpDownCounter (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createAsyncUpDownCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createDoubleGauge (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createDoubleGauge$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createDoubleHistogram (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
+	public static synthetic fun createDoubleHistogram$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
 	public abstract fun createLongGauge (Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
+	public static synthetic fun createLongGauge$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Lkotlin/jvm/functions/Function1;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/AsyncMeasurementHandle;
 	public abstract fun createLongHistogram (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
+	public static synthetic fun createLongHistogram$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/Histogram;
 	public abstract fun createMonotonicCounter (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;
+	public static synthetic fun createMonotonicCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;
 	public abstract fun createUpDownCounter (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;
+	public static synthetic fun createUpDownCounter$default (Laws/smithy/kotlin/runtime/telemetry/metrics/Meter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/Meter$Companion {
@@ -341,6 +355,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/MeterProvider$Com
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$Companion;
 	public abstract fun add (JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun add$default (Laws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter;JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$Companion {
@@ -354,6 +369,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/metrics/MonotonicCounter$
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter$Companion;
 	public abstract fun add (JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;)V
+	public static synthetic fun add$default (Laws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter;JLaws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/metrics/UpDownCounter$Companion {
@@ -427,9 +443,10 @@ public final class aws/smithy/kotlin/runtime/telemetry/trace/SpanStatus : java/l
 
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/trace/TraceSpan : aws/smithy/kotlin/runtime/telemetry/context/Scope {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan$Companion;
-	public abstract fun asContextElement ()Lkotlin/coroutines/CoroutineContext;
+	public fun asContextElement ()Lkotlin/coroutines/CoroutineContext;
 	public abstract fun close ()V
 	public abstract fun emitEvent (Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;)V
+	public static synthetic fun emitEvent$default (Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;ILjava/lang/Object;)V
 	public abstract fun getSpanContext ()Laws/smithy/kotlin/runtime/telemetry/trace/SpanContext;
 	public abstract fun mergeAttributes (Laws/smithy/kotlin/runtime/collections/Attributes;)V
 	public abstract fun set (Laws/smithy/kotlin/runtime/collections/AttributeKey;Ljava/lang/Object;)V
@@ -468,6 +485,7 @@ public final class aws/smithy/kotlin/runtime/telemetry/trace/TraceSpanExtKt {
 public abstract interface class aws/smithy/kotlin/runtime/telemetry/trace/Tracer {
 	public static final field Companion Laws/smithy/kotlin/runtime/telemetry/trace/Tracer$Companion;
 	public abstract fun createSpan (Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/trace/SpanKind;Laws/smithy/kotlin/runtime/telemetry/context/Context;)Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;
+	public static synthetic fun createSpan$default (Laws/smithy/kotlin/runtime/telemetry/trace/Tracer;Ljava/lang/String;Laws/smithy/kotlin/runtime/collections/Attributes;Laws/smithy/kotlin/runtime/telemetry/trace/SpanKind;Laws/smithy/kotlin/runtime/telemetry/context/Context;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/telemetry/trace/TraceSpan;
 }
 
 public final class aws/smithy/kotlin/runtime/telemetry/trace/Tracer$Companion {
diff --git a/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt b/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
index ac53fc26a8..172d831283 100644
--- a/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
+++ b/runtime/protocol/aws-json-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/json/AwsJsonProtocolTest.kt
@@ -6,8 +6,10 @@
 package aws.smithy.kotlin.runtime.awsprotocol.json
 
 import aws.smithy.kotlin.runtime.collections.get
-import aws.smithy.kotlin.runtime.http.*
+import aws.smithy.kotlin.runtime.http.HttpBody
+import aws.smithy.kotlin.runtime.http.SdkHttpClient
 import aws.smithy.kotlin.runtime.http.operation.*
+import aws.smithy.kotlin.runtime.http.readAll
 import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
 import aws.smithy.kotlin.runtime.http.response.HttpResponse
 import aws.smithy.kotlin.runtime.httptest.TestEngine
@@ -20,10 +22,9 @@ class AwsJsonProtocolTest {
 
     @Test
     fun testSetJsonProtocolHeaders() = runTest {
-        @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = UnitSerializer
-            deserializer = IdentityDeserializer
+            serializeWith = HttpSerializer.Unit
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
@@ -42,10 +43,9 @@ class AwsJsonProtocolTest {
 
     @Test
     fun testEmptyBody() = runTest {
-        @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = UnitSerializer
-            deserializer = IdentityDeserializer
+            serializeWith = HttpSerializer.Unit
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
@@ -63,14 +63,14 @@ class AwsJsonProtocolTest {
     fun testDoesNotOverride() = runTest {
         @Suppress("DEPRECATION")
         val op = SdkHttpOperation.build<Unit, HttpResponse> {
-            serializer = object : HttpSerialize<Unit> {
-                override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
+            serializeWith = object : HttpSerializer.NonStreaming<Unit> {
+                override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
                     HttpRequestBuilder().apply {
                         headers["Content-Type"] = "application/xml"
                         body = HttpBody.fromBytes("foo".encodeToByteArray())
                     }
             }
-            deserializer = IdentityDeserializer
+            deserializeWith = HttpDeserializer.Identity
             operationName = "Bar"
             serviceName = "Foo"
         }
diff --git a/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api b/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
index 7325432724..ab7db70f5a 100644
--- a/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
+++ b/runtime/protocol/aws-xml-protocols/api/aws-xml-protocols.api
@@ -1,10 +1,8 @@
 public final class aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerKt {
-	public static final fun parseEc2QueryErrorResponse ([BLkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static final fun parseEc2QueryErrorResponseNoSuspend ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
+	public static final fun parseEc2QueryErrorResponse ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
 }
 
 public final class aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerKt {
-	public static final fun parseRestXmlErrorResponse ([BLkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static final fun parseRestXmlErrorResponseNoSuspend ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
+	public static final fun parseRestXmlErrorResponse ([B)Laws/smithy/kotlin/runtime/awsprotocol/ErrorDetails;
 }
 
diff --git a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
index 63391e1b12..2bd349177c 100644
--- a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
+++ b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializer.kt
@@ -7,18 +7,16 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
 import aws.smithy.kotlin.runtime.serde.getOrDeserializeErr
-import aws.smithy.kotlin.runtime.serde.xml.*
+import aws.smithy.kotlin.runtime.serde.xml.XmlTagReader
+import aws.smithy.kotlin.runtime.serde.xml.data
+import aws.smithy.kotlin.runtime.serde.xml.xmlTagReader
 
 internal data class Ec2QueryErrorResponse(val errors: List<Ec2QueryError>, val requestId: String?)
 
 internal data class Ec2QueryError(val code: String?, val message: String?)
 
-@Deprecated("use parseEc2QueryErrorResponseNoSuspend")
 @InternalApi
-public suspend fun parseEc2QueryErrorResponse(payload: ByteArray): ErrorDetails =
-    parseEc2QueryErrorResponseNoSuspend(payload)
-
-public fun parseEc2QueryErrorResponseNoSuspend(payload: ByteArray): ErrorDetails {
+public fun parseEc2QueryErrorResponse(payload: ByteArray): ErrorDetails {
     val response = Ec2QueryErrorResponseDeserializer.deserialize(xmlTagReader(payload))
     val firstError = response.errors.firstOrNull()
     return ErrorDetails(firstError?.code, firstError?.message, response.requestId)
diff --git a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
index 99925c0dc1..74a9448146 100644
--- a/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
+++ b/runtime/protocol/aws-xml-protocols/common/src/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializer.kt
@@ -6,7 +6,7 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.awsprotocol.ErrorDetails
-import aws.smithy.kotlin.runtime.serde.*
+import aws.smithy.kotlin.runtime.serde.getOrDeserializeErr
 import aws.smithy.kotlin.runtime.serde.xml.XmlTagReader
 import aws.smithy.kotlin.runtime.serde.xml.data
 import aws.smithy.kotlin.runtime.serde.xml.xmlTagReader
@@ -26,18 +26,8 @@ internal data class XmlError(
     override val message: String?,
 ) : RestXmlErrorDetails
 
-/**
- * Deserializes rest XML protocol errors as specified by:
- * https://awslabs.github.io/smithy/1.0/spec/aws/aws-restxml-protocol.html#error-response-serialization
- *
- * Returns parsed data in normalized form or throws [DeserializationException] if response cannot be parsed.
- */
-@Deprecated("use parseRestXmlErrorResponseNoSuspend")
 @InternalApi
-public suspend fun parseRestXmlErrorResponse(payload: ByteArray): ErrorDetails =
-    parseRestXmlErrorResponseNoSuspend(payload)
-
-public fun parseRestXmlErrorResponseNoSuspend(payload: ByteArray): ErrorDetails {
+public fun parseRestXmlErrorResponse(payload: ByteArray): ErrorDetails {
     val details = XmlErrorDeserializer.deserialize(xmlTagReader(payload))
     return ErrorDetails(details.code, details.message, details.requestId)
 }
diff --git a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
index 6dfb531a5a..d2b4a6972e 100644
--- a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
+++ b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/Ec2QueryErrorDeserializerTest.kt
@@ -26,7 +26,7 @@ class Ec2QueryErrorDeserializerTest {
                 <RequestId>foo-request</RequestId>
             </Response>
         """.trimIndent().encodeToByteArray()
-        val actual = parseEc2QueryErrorResponseNoSuspend(payload)
+        val actual = parseEc2QueryErrorResponse(payload)
         assertEquals("InvalidGreeting", actual.code)
         assertEquals("Hi", actual.message)
         assertEquals("foo-request", actual.requestId)
@@ -61,7 +61,7 @@ class Ec2QueryErrorDeserializerTest {
 
         for (payload in tests) {
             assertFailsWith<DeserializationException> {
-                parseEc2QueryErrorResponseNoSuspend(payload)
+                parseEc2QueryErrorResponse(payload)
             }
         }
     }
@@ -90,7 +90,7 @@ class Ec2QueryErrorDeserializerTest {
         ).map { it.trimIndent().encodeToByteArray() }
 
         for (payload in tests) {
-            val actual = parseEc2QueryErrorResponseNoSuspend(payload)
+            val actual = parseEc2QueryErrorResponse(payload)
             assertNull(actual.code)
             assertNull(actual.message)
             assertEquals("foo-request", actual.requestId)
diff --git a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
index 9b94c7c31c..1f08e7bd3c 100644
--- a/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
+++ b/runtime/protocol/aws-xml-protocols/common/test/aws/smithy/kotlin/runtime/awsprotocol/xml/RestXmlErrorDeserializerTest.kt
@@ -6,7 +6,10 @@ package aws.smithy.kotlin.runtime.awsprotocol.xml
 
 import aws.smithy.kotlin.runtime.serde.DeserializationException
 import kotlinx.coroutines.test.runTest
-import kotlin.test.*
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+import kotlin.test.assertNull
 
 class RestXmlErrorDeserializerTest {
 
@@ -36,7 +39,7 @@ class RestXmlErrorDeserializerTest {
         )
 
         for (payload in tests) {
-            val actual = parseRestXmlErrorResponseNoSuspend(payload)
+            val actual = parseRestXmlErrorResponse(payload)
             assertEquals("InvalidGreeting", actual.code)
             assertEquals("Hi", actual.message)
             assertEquals("foo-id", actual.requestId)
@@ -70,7 +73,7 @@ class RestXmlErrorDeserializerTest {
 
         for (payload in tests) {
             assertFailsWith<DeserializationException> {
-                parseRestXmlErrorResponseNoSuspend(payload)
+                parseRestXmlErrorResponse(payload)
             }
         }
     }
@@ -92,7 +95,7 @@ class RestXmlErrorDeserializerTest {
         )
 
         for (payload in tests) {
-            val error = parseRestXmlErrorResponseNoSuspend(payload)
+            val error = parseRestXmlErrorResponse(payload)
             assertEquals("foo-id", error.requestId)
             assertNull(error.code)
             assertNull(error.message)
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api b/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
index 25c2339550..77e6120478 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/api/http-client-engine-okhttp.api
@@ -87,7 +87,7 @@ public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConf
 }
 
 public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineKt {
-	public static final fun buildClient (Laws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConfig;Laws/smithy/kotlin/runtime/http/engine/internal/HttpClientMetrics;)Lokhttp3/OkHttpClient;
+	public static final fun buildClient (Laws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngineConfig;Laws/smithy/kotlin/runtime/http/engine/internal/HttpClientMetrics;[Lokhttp3/EventListener;)Lokhttp3/OkHttpClient;
 }
 
 public final class aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpHeadersAdapter : aws/smithy/kotlin/runtime/http/Headers {
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
similarity index 78%
rename from runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt
rename to runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
index 3f4c366f70..131466e66e 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionIdleMonitor.kt
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/ConnectionMonitoringEventListener.kt
@@ -4,12 +4,10 @@
  */
 package aws.smithy.kotlin.runtime.http.engine.okhttp
 
+import aws.smithy.kotlin.runtime.io.Closeable
 import aws.smithy.kotlin.runtime.telemetry.logging.logger
 import kotlinx.coroutines.*
-import okhttp3.Call
-import okhttp3.Connection
-import okhttp3.ConnectionListener
-import okhttp3.ExperimentalOkHttpApi
+import okhttp3.*
 import okhttp3.internal.closeQuietly
 import okio.IOException
 import okio.buffer
@@ -22,12 +20,20 @@ import kotlin.coroutines.coroutineContext
 import kotlin.time.Duration
 import kotlin.time.measureTime
 
-@OptIn(ExperimentalOkHttpApi::class)
-internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionListener() {
+/**
+ * An [okhttp3.EventListener] implementation that monitors connections for remote closure.
+ * This replaces the functionality previously provided by the now-internal [okhttp3.ConnectionListener].
+ */
+internal class ConnectionMonitoringEventListener(private val pollInterval: Duration) :
+    EventListener(),
+    Closeable {
     private val monitorScope = CoroutineScope(Dispatchers.IO + SupervisorJob())
     private val monitors = ConcurrentHashMap<Connection, Job>()
 
-    fun close(): Unit = runBlocking {
+    /**
+     * Close all active connection monitors.
+     */
+    override fun close(): Unit = runBlocking {
         val monitorJob = requireNotNull(monitorScope.coroutineContext[Job]) {
             "Connection idle monitor scope cannot be cancelled because it does not have a job: $this"
         }
@@ -40,13 +46,16 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
             ?.callContext
             ?: Dispatchers.IO
 
-    override fun connectionAcquired(connection: Connection, call: Call) {
+    // Cancel monitoring when a connection is acquired
+    override fun connectionAcquired(call: Call, connection: Connection) {
+        super.connectionAcquired(call, connection)
+
         // Non-locking map access is okay here because this code will only execute synchronously as part of a
         // `connectionAcquired` event and will be complete before any future `connectionReleased` event could fire for
         // the same connection.
         monitors.remove(connection)?.let { monitor ->
             val context = call.callContext()
-            val logger = context.logger<ConnectionIdleMonitor>()
+            val logger = context.logger<ConnectionMonitoringEventListener>()
             logger.trace { "Cancel monitoring for $connection" }
 
             // Use `runBlocking` because this _must_ finish before OkHttp goes to use the connection
@@ -58,13 +67,18 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
         }
     }
 
-    override fun connectionReleased(connection: Connection, call: Call) {
+    // Start monitoring when a connection is released
+    override fun connectionReleased(call: Call, connection: Connection) {
+        super.connectionReleased(call, connection)
+
         val connId = System.identityHashCode(connection)
         val callContext = call.callContext()
+
+        // Start monitoring
         val monitor = monitorScope.launch(CoroutineName("okhttp-conn-monitor-for-$connId")) {
             doMonitor(connection, callContext)
         }
-        callContext.logger<ConnectionIdleMonitor>().trace { "Launched coroutine $monitor to monitor $connection" }
+        callContext.logger<ConnectionMonitoringEventListener>().trace { "Launched coroutine $monitor to monitor $connection" }
 
         // Non-locking map access is okay here because this code will only execute synchronously as part of a
         // `connectionReleased` event and will be complete before any future `connectionAcquired` event could fire for
@@ -73,7 +87,7 @@ internal class ConnectionIdleMonitor(val pollInterval: Duration) : ConnectionLis
     }
 
     private suspend fun doMonitor(conn: Connection, callContext: CoroutineContext) {
-        val logger = callContext.logger<ConnectionIdleMonitor>()
+        val logger = callContext.logger<ConnectionMonitoringEventListener>()
 
         val socket = conn.socket()
         val source = try {
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt
new file mode 100644
index 0000000000..c18bd331f3
--- /dev/null
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChain.kt
@@ -0,0 +1,115 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.http.engine.okhttp
+
+import aws.smithy.kotlin.runtime.io.closeIfCloseable
+import okhttp3.*
+import java.io.IOException
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.net.Proxy
+
+/**
+ * An [okhttp3.EventListener] that delegates to a chain of EventListeners.
+ * Start events are sent in forward order, terminal events are sent in reverse order
+ */
+internal class EventListenerChain(
+    private val listeners: List<EventListener>,
+) : EventListener() {
+    private val reverseListeners = listeners.reversed()
+
+    fun close() {
+        listeners.forEach {
+            it.closeIfCloseable()
+        }
+    }
+
+    override fun callStart(call: Call): Unit =
+        listeners.forEach { it.callStart(call) }
+
+    override fun dnsStart(call: Call, domainName: String): Unit =
+        listeners.forEach { it.dnsStart(call, domainName) }
+
+    override fun dnsEnd(call: Call, domainName: String, inetAddressList: List<InetAddress>): Unit =
+        reverseListeners.forEach { it.dnsEnd(call, domainName, inetAddressList) }
+
+    override fun proxySelectStart(call: Call, url: HttpUrl): Unit =
+        listeners.forEach { it.proxySelectStart(call, url) }
+
+    override fun proxySelectEnd(call: Call, url: HttpUrl, proxies: List<Proxy>): Unit =
+        reverseListeners.forEach { it.proxySelectEnd(call, url, proxies) }
+
+    override fun connectStart(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy): Unit =
+        listeners.forEach { it.connectStart(call, inetSocketAddress, proxy) }
+
+    override fun secureConnectStart(call: Call): Unit =
+        listeners.forEach { it.secureConnectStart(call) }
+
+    override fun secureConnectEnd(call: Call, handshake: Handshake?): Unit =
+        reverseListeners.forEach { it.secureConnectEnd(call, handshake) }
+
+    override fun connectEnd(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?): Unit =
+        reverseListeners.forEach { it.connectEnd(call, inetSocketAddress, proxy, protocol) }
+
+    override fun connectFailed(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?, ioe: IOException): Unit =
+        reverseListeners.forEach { it.connectFailed(call, inetSocketAddress, proxy, protocol, ioe) }
+
+    override fun connectionAcquired(call: Call, connection: Connection): Unit =
+        listeners.forEach { it.connectionAcquired(call, connection) }
+
+    override fun connectionReleased(call: Call, connection: Connection): Unit =
+        reverseListeners.forEach { it.connectionReleased(call, connection) }
+
+    override fun requestHeadersStart(call: Call): Unit =
+        listeners.forEach { it.requestHeadersStart(call) }
+
+    override fun requestHeadersEnd(call: Call, request: Request): Unit =
+        reverseListeners.forEach { it.requestHeadersEnd(call, request) }
+
+    override fun requestBodyStart(call: Call): Unit =
+        listeners.forEach { it.requestBodyStart(call) }
+
+    override fun requestBodyEnd(call: Call, byteCount: Long): Unit =
+        reverseListeners.forEach { it.requestBodyEnd(call, byteCount) }
+
+    override fun requestFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.requestFailed(call, ioe) }
+
+    override fun responseHeadersStart(call: Call): Unit =
+        listeners.forEach { it.responseHeadersStart(call) }
+
+    override fun responseHeadersEnd(call: Call, response: Response): Unit =
+        reverseListeners.forEach { it.responseHeadersEnd(call, response) }
+
+    override fun responseBodyStart(call: Call): Unit =
+        listeners.forEach { it.responseBodyStart(call) }
+
+    override fun responseBodyEnd(call: Call, byteCount: Long): Unit =
+        reverseListeners.forEach { it.responseBodyEnd(call, byteCount) }
+
+    override fun responseFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.responseFailed(call, ioe) }
+
+    override fun callEnd(call: Call): Unit =
+        reverseListeners.forEach { it.callEnd(call) }
+
+    override fun callFailed(call: Call, ioe: IOException): Unit =
+        reverseListeners.forEach { it.callFailed(call, ioe) }
+
+    override fun canceled(call: Call): Unit =
+        reverseListeners.forEach { it.canceled(call) }
+
+    override fun satisfactionFailure(call: Call, response: Response): Unit =
+        reverseListeners.forEach { it.satisfactionFailure(call, response) }
+
+    override fun cacheConditionalHit(call: Call, cachedResponse: Response): Unit =
+        listeners.forEach { it.cacheConditionalHit(call, cachedResponse) }
+
+    override fun cacheHit(call: Call, response: Response): Unit =
+        listeners.forEach { it.cacheHit(call, response) }
+
+    override fun cacheMiss(call: Call): Unit =
+        listeners.forEach { it.cacheMiss(call) }
+}
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
index a20387d0a0..297e015eed 100644
--- a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/src/aws/smithy/kotlin/runtime/http/engine/okhttp/OkHttpEngine.kt
@@ -8,9 +8,13 @@ package aws.smithy.kotlin.runtime.http.engine.okhttp
 import aws.smithy.kotlin.runtime.InternalApi
 import aws.smithy.kotlin.runtime.http.HttpCall
 import aws.smithy.kotlin.runtime.http.config.EngineFactory
-import aws.smithy.kotlin.runtime.http.engine.*
+import aws.smithy.kotlin.runtime.http.engine.AlpnId
+import aws.smithy.kotlin.runtime.http.engine.HttpClientEngineBase
+import aws.smithy.kotlin.runtime.http.engine.TlsContext
+import aws.smithy.kotlin.runtime.http.engine.callContext
 import aws.smithy.kotlin.runtime.http.engine.internal.HttpClientMetrics
 import aws.smithy.kotlin.runtime.http.request.HttpRequest
+import aws.smithy.kotlin.runtime.io.closeIfCloseable
 import aws.smithy.kotlin.runtime.net.TlsVersion
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 import aws.smithy.kotlin.runtime.time.Instant
@@ -18,7 +22,6 @@ import aws.smithy.kotlin.runtime.time.fromEpochMilliseconds
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.job
 import okhttp3.*
-import okhttp3.ConnectionPool
 import okhttp3.coroutines.executeAsync
 import java.util.concurrent.TimeUnit
 import kotlin.time.toJavaDuration
@@ -44,9 +47,14 @@ public class OkHttpEngine(
         override val engineConstructor: (OkHttpEngineConfig.Builder.() -> Unit) -> OkHttpEngine = ::invoke
     }
 
+    // Create a single shared connection monitoring listener if idle polling is enabled
+    private val connectionMonitoringListener: EventListener? =
+        config.connectionIdlePollingInterval?.let {
+            ConnectionMonitoringEventListener(it)
+        }
+
     private val metrics = HttpClientMetrics(TELEMETRY_SCOPE, config.telemetryProvider)
-    private val connectionIdleMonitor = config.connectionIdlePollingInterval?.let { ConnectionIdleMonitor(it) }
-    private val client = config.buildClientWithConnectionListener(metrics, connectionIdleMonitor)
+    private val client = config.buildClient(metrics, connectionMonitoringListener)
 
     @OptIn(ExperimentalCoroutinesApi::class)
     override suspend fun roundTrip(context: ExecutionContext, request: HttpRequest): HttpCall {
@@ -73,16 +81,20 @@ public class OkHttpEngine(
     }
 
     override fun shutdown() {
-        connectionIdleMonitor?.close()
+        connectionMonitoringListener?.closeIfCloseable()
         client.connectionPool.evictAll()
         client.dispatcher.executorService.shutdown()
         metrics.close()
     }
 }
 
-private fun OkHttpEngineConfig.buildClientFromConfig(
+/**
+ * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
+ */
+@InternalApi
+public fun OkHttpEngineConfig.buildClient(
     metrics: HttpClientMetrics,
-    poolOverride: ConnectionPool? = null,
+    vararg clientScopedEventListeners: EventListener?,
 ): OkHttpClient {
     val config = this
 
@@ -102,7 +114,7 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
         writeTimeout(config.socketWriteTimeout.toJavaDuration())
 
         // use our own pool configured with the timeout settings taken from config
-        val pool = poolOverride ?: ConnectionPool(
+        val pool = ConnectionPool(
             maxIdleConnections = 5, // The default from the no-arg ConnectionPool() constructor
             keepAliveDuration = config.connectionIdleTimeout.inWholeMilliseconds,
             TimeUnit.MILLISECONDS,
@@ -116,7 +128,14 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
         dispatcher(dispatcher)
 
         // Log events coming from okhttp. Allocate a new listener per-call to facilitate dedicated trace spans.
-        eventListenerFactory { call -> HttpEngineEventListener(pool, config.hostResolver, dispatcher, metrics, call) }
+        eventListenerFactory { call ->
+            EventListenerChain(
+                listOfNotNull(
+                    HttpEngineEventListener(pool, config.hostResolver, dispatcher, metrics, call),
+                    *clientScopedEventListeners,
+                ),
+            )
+        }
 
         // map protocols
         if (config.tlsContext.alpn.isNotEmpty()) {
@@ -140,34 +159,6 @@ private fun OkHttpEngineConfig.buildClientFromConfig(
     }.build()
 }
 
-/**
- * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
- */
-// Used by OkHttp4Engine - OkHttp4 does NOT have `connectionListener`
-// TODO - Refactor in next minor version - Move this to OkHttp4Engine and make it private
-@InternalApi
-public fun OkHttpEngineConfig.buildClient(
-    metrics: HttpClientMetrics,
-): OkHttpClient = this.buildClientFromConfig(metrics)
-
-/**
- * Convert SDK version of HTTP configuration to OkHttp specific configuration and return the configured client
- */
-// Used by OkHttpEngine - OkHttp5 does have `connectionListener`
-@OptIn(ExperimentalOkHttpApi::class)
-private fun OkHttpEngineConfig.buildClientWithConnectionListener(
-    metrics: HttpClientMetrics,
-    connectionListener: ConnectionIdleMonitor?,
-): OkHttpClient = this.buildClientFromConfig(
-    metrics,
-    ConnectionPool(
-        maxIdleConnections = 5, // The default from the no-arg ConnectionPool() constructor
-        keepAliveDuration = this.connectionIdleTimeout.inWholeMilliseconds,
-        timeUnit = TimeUnit.MILLISECONDS,
-        connectionListener = connectionListener ?: ConnectionListener.NONE,
-    ),
-)
-
 private fun minTlsConnectionSpec(tlsContext: TlsContext): ConnectionSpec {
     val minVersion = tlsContext.minVersion ?: TlsVersion.TLS_1_2
     val okHttpTlsVersions = SdkTlsVersion
diff --git a/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt
new file mode 100644
index 0000000000..c9acb07cef
--- /dev/null
+++ b/runtime/protocol/http-client-engines/http-client-engine-okhttp/jvm/test/aws/smithy/kotlin/runtime/http/engine/okhttp/EventListenerChainTest.kt
@@ -0,0 +1,281 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.http.engine.okhttp
+
+import okhttp3.*
+import java.io.Closeable
+import java.io.IOException
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.net.Proxy
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class EventListenerChainTest {
+    @Test
+    fun testForwardEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test forward events
+        chain.callStart(call)
+        chain.dnsStart(call, "example.com")
+        chain.proxySelectStart(call, createHttpUrl())
+
+        // Verify forward events were called in order (listener1 first, then listener2)
+        assertEquals("listener1:callStart", eventOrder[0])
+        assertEquals("listener2:callStart", eventOrder[1])
+        assertEquals("listener1:dnsStart", eventOrder[2])
+        assertEquals("listener2:dnsStart", eventOrder[3])
+        assertEquals("listener1:proxySelectStart", eventOrder[4])
+        assertEquals("listener2:proxySelectStart", eventOrder[5])
+    }
+
+    @Test
+    fun testReverseEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test reverse events
+        chain.dnsEnd(call, "example.com", listOf())
+        chain.proxySelectEnd(call, createHttpUrl(), listOf())
+        chain.callEnd(call)
+
+        // Verify reverse events were called in reverse order (listener2 first, then listener1)
+        assertEquals("listener2:dnsEnd", eventOrder[0])
+        assertEquals("listener1:dnsEnd", eventOrder[1])
+        assertEquals("listener2:proxySelectEnd", eventOrder[2])
+        assertEquals("listener1:proxySelectEnd", eventOrder[3])
+        assertEquals("listener2:callEnd", eventOrder[4])
+        assertEquals("listener1:callEnd", eventOrder[5])
+    }
+
+    @Test
+    fun testClose() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        // Close the chain
+        chain.close()
+
+        // Verify all listeners were closed
+        assertTrue(listener1.closed)
+        assertTrue(listener2.closed)
+    }
+
+    @Test
+    fun testMixedEvents() {
+        val eventOrder = mutableListOf<String>()
+
+        val listener1 = TestEventListener("listener1", eventOrder)
+        val listener2 = TestEventListener("listener2", eventOrder)
+
+        val chain = EventListenerChain(listOf(listener1, listener2))
+
+        val call = createMockCall()
+
+        // Test mixed forward and reverse events
+        chain.callStart(call)
+        chain.dnsStart(call, "example.com")
+        chain.dnsEnd(call, "example.com", listOf())
+
+        // Verify the order of events
+        assertEquals("listener1:callStart", eventOrder[0]) // listener1 first (forward)
+        assertEquals("listener2:callStart", eventOrder[1]) // listener2 second (forward)
+        assertEquals("listener1:dnsStart", eventOrder[2]) // listener1 first (forward)
+        assertEquals("listener2:dnsStart", eventOrder[3]) // listener2 second (forward)
+        assertEquals("listener2:dnsEnd", eventOrder[4]) // listener2 first (reverse)
+        assertEquals("listener1:dnsEnd", eventOrder[5]) // listener1 second (reverse)
+
+        // Clear event order
+        eventOrder.clear()
+
+        // Test more events to verify the sequence
+        chain.requestHeadersStart(call) // forward event
+        chain.requestHeadersEnd(call, Request.Builder().url("https://example.com").build()) // reverse event
+        chain.responseHeadersStart(call) // forward event
+        chain.responseHeadersEnd(
+            call,
+            Response.Builder()
+                .request(Request.Builder().url("https://example.com").build())
+                .protocol(Protocol.HTTP_2)
+                .code(200)
+                .message("OK")
+                .build(),
+        ) // reverse event
+
+        // Verify the sequence of events
+        assertEquals("listener1:requestHeadersStart", eventOrder[0]) // listener1 first (forward)
+        assertEquals("listener2:requestHeadersStart", eventOrder[1]) // listener2 second (forward)
+        assertEquals("listener2:requestHeadersEnd", eventOrder[2]) // listener2 first (reverse)
+        assertEquals("listener1:requestHeadersEnd", eventOrder[3]) // listener1 second (reverse)
+        assertEquals("listener1:responseHeadersStart", eventOrder[4]) // listener1 first (forward)
+        assertEquals("listener2:responseHeadersStart", eventOrder[5]) // listener2 second (forward)
+        assertEquals("listener2:responseHeadersEnd", eventOrder[6]) // listener2 first (reverse)
+        assertEquals("listener1:responseHeadersEnd", eventOrder[7]) // listener1 second (reverse)
+    }
+
+    // A test EventListener that records the order of calls
+    private class TestEventListener(val name: String, val eventOrder: MutableList<String>) :
+        EventListener(),
+        Closeable {
+        var closed = false
+
+        override fun callStart(call: Call) {
+            eventOrder.add("$name:callStart")
+        }
+
+        override fun dnsStart(call: Call, domainName: String) {
+            eventOrder.add("$name:dnsStart")
+        }
+
+        override fun dnsEnd(call: Call, domainName: String, inetAddressList: List<InetAddress>) {
+            eventOrder.add("$name:dnsEnd")
+        }
+
+        override fun proxySelectStart(call: Call, url: HttpUrl) {
+            eventOrder.add("$name:proxySelectStart")
+        }
+
+        override fun proxySelectEnd(call: Call, url: HttpUrl, proxies: List<Proxy>) {
+            eventOrder.add("$name:proxySelectEnd")
+        }
+
+        override fun connectStart(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy) {
+            eventOrder.add("$name:connectStart")
+        }
+
+        override fun secureConnectStart(call: Call) {
+            eventOrder.add("$name:secureConnectStart")
+        }
+
+        override fun secureConnectEnd(call: Call, handshake: Handshake?) {
+            eventOrder.add("$name:secureConnectEnd")
+        }
+
+        override fun connectEnd(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?) {
+            eventOrder.add("$name:connectEnd")
+        }
+
+        override fun connectFailed(call: Call, inetSocketAddress: InetSocketAddress, proxy: Proxy, protocol: Protocol?, ioe: IOException) {
+            eventOrder.add("$name:connectFailed")
+        }
+
+        override fun connectionAcquired(call: Call, connection: Connection) {
+            eventOrder.add("$name:connectionAcquired")
+        }
+
+        override fun connectionReleased(call: Call, connection: Connection) {
+            eventOrder.add("$name:connectionReleased")
+        }
+
+        override fun requestHeadersStart(call: Call) {
+            eventOrder.add("$name:requestHeadersStart")
+        }
+
+        override fun requestHeadersEnd(call: Call, request: Request) {
+            eventOrder.add("$name:requestHeadersEnd")
+        }
+
+        override fun requestBodyStart(call: Call) {
+            eventOrder.add("$name:requestBodyStart")
+        }
+
+        override fun requestBodyEnd(call: Call, byteCount: Long) {
+            eventOrder.add("$name:requestBodyEnd")
+        }
+
+        override fun requestFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:requestFailed")
+        }
+
+        override fun responseHeadersStart(call: Call) {
+            eventOrder.add("$name:responseHeadersStart")
+        }
+
+        override fun responseHeadersEnd(call: Call, response: Response) {
+            eventOrder.add("$name:responseHeadersEnd")
+        }
+
+        override fun responseBodyStart(call: Call) {
+            eventOrder.add("$name:responseBodyStart")
+        }
+
+        override fun responseBodyEnd(call: Call, byteCount: Long) {
+            eventOrder.add("$name:responseBodyEnd")
+        }
+
+        override fun responseFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:responseFailed")
+        }
+
+        override fun callEnd(call: Call) {
+            eventOrder.add("$name:callEnd")
+        }
+
+        override fun callFailed(call: Call, ioe: IOException) {
+            eventOrder.add("$name:callFailed")
+        }
+
+        override fun canceled(call: Call) {
+            eventOrder.add("$name:canceled")
+        }
+
+        override fun satisfactionFailure(call: Call, response: Response) {
+            eventOrder.add("$name:satisfactionFailure")
+        }
+
+        override fun cacheConditionalHit(call: Call, cachedResponse: Response) {
+            eventOrder.add("$name:cacheConditionalHit")
+        }
+
+        override fun cacheHit(call: Call, response: Response) {
+            eventOrder.add("$name:cacheHit")
+        }
+
+        override fun cacheMiss(call: Call) {
+            eventOrder.add("$name:cacheMiss")
+        }
+
+        override fun close() {
+            closed = true
+        }
+    }
+
+    // Helper methods to create mock objects
+    private fun createMockCall(): Call = object : Call {
+        override fun cancel() {}
+        override fun clone(): Call = this
+        override fun enqueue(responseCallback: Callback) {}
+        override fun execute(): Response = throw UnsupportedOperationException()
+        override fun isCanceled(): Boolean = false
+        override fun isExecuted(): Boolean = false
+        override fun request(): Request = Request.Builder().url("https://example.com").build()
+        override fun timeout(): okio.Timeout = okio.Timeout()
+    }
+
+    private fun createHttpUrl(): HttpUrl = HttpUrl.Builder()
+        .scheme("https")
+        .host("example.com")
+        .build()
+}
diff --git a/runtime/protocol/http-client/api/http-client.api b/runtime/protocol/http-client/api/http-client.api
index 9a752b6788..1d8deaa751 100644
--- a/runtime/protocol/http-client/api/http-client.api
+++ b/runtime/protocol/http-client/api/http-client.api
@@ -29,6 +29,8 @@ public abstract interface class aws/smithy/kotlin/runtime/http/config/HttpEngine
 	public abstract fun getHttpClient ()Laws/smithy/kotlin/runtime/http/engine/HttpClientEngine;
 	public abstract fun httpClient (Laws/smithy/kotlin/runtime/http/config/EngineFactory;Lkotlin/jvm/functions/Function1;)V
 	public abstract fun httpClient (Lkotlin/jvm/functions/Function1;)V
+	public static synthetic fun httpClient$default (Laws/smithy/kotlin/runtime/http/config/HttpEngineConfig$Builder;Laws/smithy/kotlin/runtime/http/config/EngineFactory;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
+	public static synthetic fun httpClient$default (Laws/smithy/kotlin/runtime/http/config/HttpEngineConfig$Builder;Lkotlin/jvm/functions/Function1;ILjava/lang/Object;)V
 	public abstract fun setHttpClient (Laws/smithy/kotlin/runtime/http/engine/HttpClientEngine;)V
 }
 
@@ -309,7 +311,7 @@ public final class aws/smithy/kotlin/runtime/http/interceptors/ContinueIntercept
 }
 
 public final class aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor : aws/smithy/kotlin/runtime/client/Interceptor {
-	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function1;)V
+	public fun <init> (Lkotlin/reflect/KClass;Lkotlin/jvm/functions/Function2;)V
 	public fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -495,11 +497,13 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/Endpoin
 	public abstract fun resolve (Laws/smithy/kotlin/runtime/http/operation/ResolveEndpointRequest;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public abstract fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
+	public static final field Companion Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer$Companion;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
+public final class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer$Companion {
+	public final fun getIdentity ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
+	public final fun getUnit ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpDeserializer$NonStreaming : aws/smithy/kotlin/runtime/http/operation/HttpDeserializer {
@@ -523,11 +527,12 @@ public final class aws/smithy/kotlin/runtime/http/operation/HttpOperationContext
 	public final fun getSdkInvocationId ()Laws/smithy/kotlin/runtime/collections/AttributeKey;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerialize {
-	public abstract fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
+	public static final field Companion Laws/smithy/kotlin/runtime/http/operation/HttpSerializer$Companion;
 }
 
-public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
+public final class aws/smithy/kotlin/runtime/http/operation/HttpSerializer$Companion {
+	public final fun getUnit ()Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSerializer$NonStreaming : aws/smithy/kotlin/runtime/http/operation/HttpSerializer {
@@ -538,13 +543,8 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/HttpSer
 	public abstract fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public final class aws/smithy/kotlin/runtime/http/operation/IdentityDeserializer : aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/IdentityDeserializer;
-	public fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/InitializeMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/InitializeMiddleware$DefaultImpls {
@@ -556,7 +556,7 @@ public abstract interface class aws/smithy/kotlin/runtime/http/operation/InlineM
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddleware : aws/smithy/kotlin/runtime/io/middleware/ModifyRequest {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddleware$DefaultImpls {
@@ -564,7 +564,7 @@ public final class aws/smithy/kotlin/runtime/http/operation/ModifyRequestMiddlew
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/MutateMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/MutateMiddleware$DefaultImpls {
@@ -633,7 +633,7 @@ public final class aws/smithy/kotlin/runtime/http/operation/OperationTelemetryKt
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/http/operation/ReceiveMiddleware : aws/smithy/kotlin/runtime/io/middleware/Middleware {
-	public abstract fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
+	public fun install (Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;)V
 }
 
 public final class aws/smithy/kotlin/runtime/http/operation/ReceiveMiddleware$DefaultImpls {
@@ -675,20 +675,16 @@ public final class aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationBuil
 	public final fun build ()Laws/smithy/kotlin/runtime/http/operation/SdkHttpOperation;
 	public final fun getContext ()Laws/smithy/kotlin/runtime/operation/ExecutionContext;
 	public final fun getDeserializeWith ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;
-	public final fun getDeserializer ()Laws/smithy/kotlin/runtime/http/operation/HttpDeserialize;
 	public final fun getExecution ()Laws/smithy/kotlin/runtime/http/operation/SdkOperationExecution;
 	public final fun getHostPrefix ()Ljava/lang/String;
 	public final fun getOperationName ()Ljava/lang/String;
 	public final fun getSerializeWith ()Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;
-	public final fun getSerializer ()Laws/smithy/kotlin/runtime/http/operation/HttpSerialize;
 	public final fun getServiceName ()Ljava/lang/String;
 	public final fun getTelemetry ()Laws/smithy/kotlin/runtime/http/operation/SdkOperationTelemetry;
 	public final fun setDeserializeWith (Laws/smithy/kotlin/runtime/http/operation/HttpDeserializer;)V
-	public final fun setDeserializer (Laws/smithy/kotlin/runtime/http/operation/HttpDeserialize;)V
 	public final fun setHostPrefix (Ljava/lang/String;)V
 	public final fun setOperationName (Ljava/lang/String;)V
 	public final fun setSerializeWith (Laws/smithy/kotlin/runtime/http/operation/HttpSerializer;)V
-	public final fun setSerializer (Laws/smithy/kotlin/runtime/http/operation/HttpSerialize;)V
 	public final fun setServiceName (Ljava/lang/String;)V
 }
 
@@ -731,14 +727,3 @@ public final class aws/smithy/kotlin/runtime/http/operation/SdkOperationTelemetr
 	public final fun setSpanName (Ljava/lang/String;)V
 }
 
-public final class aws/smithy/kotlin/runtime/http/operation/UnitDeserializer : aws/smithy/kotlin/runtime/http/operation/HttpDeserialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/UnitDeserializer;
-	public fun deserialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Laws/smithy/kotlin/runtime/http/HttpCall;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
-public final class aws/smithy/kotlin/runtime/http/operation/UnitSerializer : aws/smithy/kotlin/runtime/http/operation/HttpSerialize {
-	public static final field INSTANCE Laws/smithy/kotlin/runtime/http/operation/UnitSerializer;
-	public synthetic fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public fun serialize (Laws/smithy/kotlin/runtime/operation/ExecutionContext;Lkotlin/Unit;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-}
-
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
index ce1ef41857..adb4babd48 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/interceptors/DiscoveredEndpointErrorInterceptor.kt
@@ -23,7 +23,7 @@ import kotlin.reflect.KClass
 @InternalApi
 public class DiscoveredEndpointErrorInterceptor(
     private val errorType: KClass<out ServiceException>,
-    private val invalidate: (ExecutionContext) -> Unit,
+    private val invalidate: suspend (ExecutionContext) -> Unit,
 ) : HttpInterceptor {
     override suspend fun modifyBeforeAttemptCompletion(
         context: ResponseInterceptorContext<Any, Any, HttpRequest, HttpResponse?>,
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
index 5e50a3cca9..b50a05d037 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/HttpSerde.kt
@@ -15,6 +15,13 @@ import aws.smithy.kotlin.runtime.operation.ExecutionContext
  */
 @InternalApi
 public sealed interface HttpSerializer<T> {
+    @InternalApi
+    public companion object {
+        public val Unit: HttpSerializer<Unit> = object : NonStreaming<Unit> {
+            override fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder =
+                HttpRequestBuilder()
+        }
+    }
 
     /**
      * Serializer for streaming operations that need full control over serialization of the body
@@ -38,6 +45,17 @@ public sealed interface HttpSerializer<T> {
  */
 @InternalApi
 public sealed interface HttpDeserializer<T> {
+    @InternalApi
+    public companion object {
+        public val Identity: HttpDeserializer<HttpResponse> = object : NonStreaming<HttpResponse> {
+            override fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?): HttpResponse =
+                call.response
+        }
+
+        public val Unit: HttpDeserializer<Unit> = object : NonStreaming<Unit> {
+            override fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?) { }
+        }
+    }
 
     /**
      * Deserializer for streaming operations that need full control over deserialization of the body
@@ -56,66 +74,3 @@ public sealed interface HttpDeserializer<T> {
         public fun deserialize(context: ExecutionContext, call: HttpCall, payload: ByteArray?): T
     }
 }
-
-/**
- * Implemented by types that know how to serialize to the HTTP protocol.
- */
-@Deprecated("use HttpSerializer.Streaming")
-@InternalApi
-public fun interface HttpSerialize<T> {
-    public suspend fun serialize(context: ExecutionContext, input: T): HttpRequestBuilder
-}
-
-@Suppress("DEPRECATION")
-private class LegacyHttpSerializeAdapter<T>(val serializer: HttpSerialize<T>) : HttpSerializer.Streaming<T> {
-    override suspend fun serialize(context: ExecutionContext, input: T): HttpRequestBuilder =
-        serializer.serialize(context, input)
-}
-
-@Suppress("DEPRECATION")
-internal fun <T> HttpSerialize<T>.intoSerializer(): HttpSerializer<T> = LegacyHttpSerializeAdapter(this)
-
-/**
- * Implemented by types that know how to deserialize from the HTTP protocol.
- */
-@Deprecated("use HttpDeserializer.Streaming")
-@InternalApi
-public fun interface HttpDeserialize<T> {
-    public suspend fun deserialize(context: ExecutionContext, call: HttpCall): T
-}
-
-@Suppress("DEPRECATION")
-private class LegacyHttpDeserializeAdapter<T>(val deserializer: HttpDeserialize<T>) : HttpDeserializer.Streaming<T> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall): T =
-        deserializer.deserialize(context, call)
-}
-
-@Suppress("DEPRECATION")
-internal fun <T> HttpDeserialize<T>.intoDeserializer(): HttpDeserializer<T> = LegacyHttpDeserializeAdapter(this)
-
-/**
- * Convenience deserialize implementation for a type with no output type
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object UnitDeserializer : HttpDeserialize<Unit> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall) {}
-}
-
-/**
- * Convenience serialize implementation for a type with no input type
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object UnitSerializer : HttpSerialize<Unit> {
-    override suspend fun serialize(context: ExecutionContext, input: Unit): HttpRequestBuilder = HttpRequestBuilder()
-}
-
-/**
- * Convenience deserialize implementation that returns the response without modification
- */
-@Suppress("DEPRECATION")
-@InternalApi
-public object IdentityDeserializer : HttpDeserialize<HttpResponse> {
-    override suspend fun deserialize(context: ExecutionContext, call: HttpCall): HttpResponse = call.response
-}
diff --git a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
index 775da6c891..abb3b8cc46 100644
--- a/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
+++ b/runtime/protocol/http-client/common/src/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperation.kt
@@ -36,17 +36,6 @@ public class SdkHttpOperation<I, O> internal constructor(
     internal val typeInfo: OperationTypeInfo,
     internal val telemetry: SdkOperationTelemetry,
 ) {
-
-    @Suppress("DEPRECATION")
-    internal constructor(
-        execution: SdkOperationExecution<I, O>,
-        context: ExecutionContext,
-        serializer: HttpSerialize<I>,
-        deserializer: HttpDeserialize<O>,
-        typeInfo: OperationTypeInfo,
-        telemetry: SdkOperationTelemetry,
-    ) : this(execution, context, serializer.intoSerializer(), deserializer.intoDeserializer(), typeInfo, telemetry)
-
     init {
         context[HttpOperationContext.SdkInvocationId] = Uuid.random().toString()
     }
@@ -142,27 +131,8 @@ public class SdkHttpOperationBuilder<I, O>(
     private val outputType: KClass<*>,
 ) {
     public val telemetry: SdkOperationTelemetry = SdkOperationTelemetry()
-
-    @Suppress("DEPRECATION")
-    @Deprecated("use serializeWith")
-    public var serializer: HttpSerialize<I>? = null
-        set(value) {
-            field = value
-            serializeWith = value?.intoSerializer()
-        }
-
     public var serializeWith: HttpSerializer<I>? = null
-
-    @Suppress("DEPRECATION")
-    @Deprecated("use deserializeWith")
-    public var deserializer: HttpDeserialize<O>? = null
-        set(value) {
-            field = value
-            deserializeWith = value?.intoDeserializer()
-        }
-
     public var deserializeWith: HttpDeserializer<O>? = null
-
     public val execution: SdkOperationExecution<I, O> = SdkOperationExecution()
     public val context: ExecutionContext = ExecutionContext()
 
diff --git a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
index 22e36d1cf1..e564bedcc2 100644
--- a/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
+++ b/runtime/protocol/http-client/common/test/aws/smithy/kotlin/runtime/http/operation/SdkHttpOperationTest.kt
@@ -36,8 +36,8 @@ class SdkHttpOperationTest {
         val ex = assertFailsWith<IllegalArgumentException> {
             @Suppress("DEPRECATION")
             SdkHttpOperation.build<Unit, Unit> {
-                serializer = UnitSerializer
-                deserializer = UnitDeserializer
+                serializeWith = HttpSerializer.Unit
+                deserializeWith = HttpDeserializer.Unit
             }
         }
 
diff --git a/runtime/runtime-core/api/runtime-core.api b/runtime/runtime-core/api/runtime-core.api
index fa4c1d2d2e..91855f6e4d 100644
--- a/runtime/runtime-core/api/runtime-core.api
+++ b/runtime/runtime-core/api/runtime-core.api
@@ -177,6 +177,12 @@ public final class aws/smithy/kotlin/runtime/collections/CollectionExtKt {
 	public static final fun createOrAppend (Ljava/util/List;Ljava/lang/Object;)Ljava/util/List;
 }
 
+public abstract interface class aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache {
+	public abstract fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public abstract fun getSize ()I
+	public abstract fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
 public final class aws/smithy/kotlin/runtime/collections/LruCache {
 	public fun <init> (I)V
 	public final fun get (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -188,9 +194,9 @@ public final class aws/smithy/kotlin/runtime/collections/LruCache {
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/collections/MultiMap : java/util/Map, kotlin/jvm/internal/markers/KMappedMarker {
-	public abstract fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
+	public fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun getEntryValues ()Lkotlin/sequences/Sequence;
-	public abstract fun toMutableMultiMap ()Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
+	public fun toMutableMultiMap ()Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/MultiMap$DefaultImpls {
@@ -213,15 +219,15 @@ public abstract interface class aws/smithy/kotlin/runtime/collections/MutableMul
 	public abstract fun add (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun addAll (Ljava/lang/Object;ILjava/util/Collection;)Z
 	public abstract fun addAll (Ljava/lang/Object;Ljava/util/Collection;)Z
-	public abstract fun addAll (Ljava/util/Map;)V
-	public abstract fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
+	public fun addAll (Ljava/util/Map;)V
+	public fun contains (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun getEntryValues ()Lkotlin/sequences/Sequence;
-	public abstract fun put (Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/List;
+	public fun put (Ljava/lang/Object;Ljava/lang/Object;)Ljava/util/List;
 	public abstract fun removeAll (Ljava/lang/Object;Ljava/util/Collection;)Ljava/lang/Boolean;
 	public abstract fun removeAt (Ljava/lang/Object;I)Ljava/lang/Object;
 	public abstract fun removeElement (Ljava/lang/Object;Ljava/lang/Object;)Z
 	public abstract fun retainAll (Ljava/lang/Object;Ljava/util/Collection;)Ljava/lang/Boolean;
-	public abstract fun toMultiMap ()Laws/smithy/kotlin/runtime/collections/MultiMap;
+	public fun toMultiMap ()Laws/smithy/kotlin/runtime/collections/MultiMap;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/MutableMultiMap$DefaultImpls {
@@ -235,12 +241,12 @@ public final class aws/smithy/kotlin/runtime/collections/MutableMultiMapKt {
 	public static final fun mutableMultiMapOf ([Lkotlin/Pair;)Laws/smithy/kotlin/runtime/collections/MutableMultiMap;
 }
 
-public final class aws/smithy/kotlin/runtime/collections/ReadThroughCache {
+public final class aws/smithy/kotlin/runtime/collections/PeriodicSweepCache : aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache {
 	public synthetic fun <init> (JLaws/smithy/kotlin/runtime/time/Clock;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public synthetic fun <init> (JLaws/smithy/kotlin/runtime/time/Clock;Lkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public final fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public final fun getSize ()I
-	public final fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun get (Ljava/lang/Object;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun getSize ()I
+	public fun invalidate (Ljava/lang/Object;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/collections/StackKt {
@@ -254,10 +260,10 @@ public final class aws/smithy/kotlin/runtime/collections/StackKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/collections/ValuesMap {
 	public abstract fun contains (Ljava/lang/String;)Z
-	public abstract fun contains (Ljava/lang/String;Ljava/lang/Object;)Z
+	public fun contains (Ljava/lang/String;Ljava/lang/Object;)Z
 	public abstract fun entries ()Ljava/util/Set;
-	public abstract fun forEach (Lkotlin/jvm/functions/Function2;)V
-	public abstract fun get (Ljava/lang/String;)Ljava/lang/Object;
+	public fun forEach (Lkotlin/jvm/functions/Function2;)V
+	public fun get (Ljava/lang/String;)Ljava/lang/Object;
 	public abstract fun getAll (Ljava/lang/String;)Ljava/util/List;
 	public abstract fun getCaseInsensitiveName ()Z
 	public abstract fun isEmpty ()Z
@@ -707,6 +713,7 @@ public abstract interface class aws/smithy/kotlin/runtime/hashing/HashFunction {
 	public abstract fun getDigestSizeBytes ()I
 	public abstract fun reset ()V
 	public abstract fun update ([BII)V
+	public static synthetic fun update$default (Laws/smithy/kotlin/runtime/hashing/HashFunction;[BIIILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/hashing/HashFunction$DefaultImpls {
@@ -903,6 +910,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSink : a
 	public abstract fun outputStream ()Ljava/io/OutputStream;
 	public abstract fun write (Laws/smithy/kotlin/runtime/io/SdkSource;J)V
 	public abstract fun write ([BII)V
+	public static synthetic fun write$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSink;[BIIILjava/lang/Object;)V
 	public abstract fun writeAll (Laws/smithy/kotlin/runtime/io/SdkSource;)J
 	public abstract fun writeByte (B)V
 	public abstract fun writeInt (I)V
@@ -912,6 +920,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSink : a
 	public abstract fun writeShort (S)V
 	public abstract fun writeShortLe (S)V
 	public abstract fun writeUtf8 (Ljava/lang/String;II)V
+	public static synthetic fun writeUtf8$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSink;Ljava/lang/String;IIILjava/lang/Object;)V
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkBufferedSink$DefaultImpls {
@@ -925,6 +934,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkBufferedSource :
 	public abstract fun inputStream ()Ljava/io/InputStream;
 	public abstract fun peek ()Laws/smithy/kotlin/runtime/io/SdkBufferedSource;
 	public abstract fun read ([BII)I
+	public static synthetic fun read$default (Laws/smithy/kotlin/runtime/io/SdkBufferedSource;[BIIILjava/lang/Object;)I
 	public abstract fun readAll (Laws/smithy/kotlin/runtime/io/SdkSink;)J
 	public abstract fun readByte ()B
 	public abstract fun readByteArray ()[B
@@ -947,7 +957,7 @@ public final class aws/smithy/kotlin/runtime/io/SdkBufferedSource$DefaultImpls {
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/io/SdkByteChannel : aws/smithy/kotlin/runtime/io/SdkByteReadChannel, aws/smithy/kotlin/runtime/io/SdkByteWriteChannel {
-	public abstract fun close ()V
+	public fun close ()V
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkByteChannel$DefaultImpls {
@@ -994,6 +1004,7 @@ public abstract interface class aws/smithy/kotlin/runtime/io/SdkByteWriteChannel
 	public abstract fun getTotalBytesWritten ()J
 	public abstract fun isClosedForWrite ()Z
 	public abstract fun write (Laws/smithy/kotlin/runtime/io/SdkBuffer;JLkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun write$default (Laws/smithy/kotlin/runtime/io/SdkByteWriteChannel;Laws/smithy/kotlin/runtime/io/SdkBuffer;JLkotlin/coroutines/Continuation;ILjava/lang/Object;)Ljava/lang/Object;
 }
 
 public final class aws/smithy/kotlin/runtime/io/SdkByteWriteChannel$DefaultImpls {
@@ -1217,6 +1228,7 @@ public final class aws/smithy/kotlin/runtime/net/HostKt {
 public abstract interface class aws/smithy/kotlin/runtime/net/HostResolver {
 	public static final field Companion Laws/smithy/kotlin/runtime/net/HostResolver$Companion;
 	public abstract fun purgeCache (Laws/smithy/kotlin/runtime/net/HostAddress;)V
+	public static synthetic fun purgeCache$default (Laws/smithy/kotlin/runtime/net/HostResolver;Laws/smithy/kotlin/runtime/net/HostAddress;ILjava/lang/Object;)V
 	public abstract fun reportFailure (Laws/smithy/kotlin/runtime/net/HostAddress;)V
 	public abstract fun resolve (Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
@@ -2094,7 +2106,6 @@ public final class aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctionsJVMKt
 
 public final class aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctionsKt {
 	public static final fun getDefaultPrinter ()Ljava/lang/Appendable;
-	public static final fun printExceptionStackTrace (Ljava/lang/Exception;)V
 }
 
 public final class aws/smithy/kotlin/runtime/text/Scanner {
@@ -2150,8 +2161,8 @@ public final class aws/smithy/kotlin/runtime/text/encoding/Encodable$Companion {
 public abstract interface class aws/smithy/kotlin/runtime/text/encoding/Encoding {
 	public static final field Companion Laws/smithy/kotlin/runtime/text/encoding/Encoding$Companion;
 	public abstract fun decode (Ljava/lang/String;)Ljava/lang/String;
-	public abstract fun encodableFromDecoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
-	public abstract fun encodableFromEncoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
+	public fun encodableFromDecoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
+	public fun encodableFromEncoded (Ljava/lang/String;)Laws/smithy/kotlin/runtime/text/encoding/Encodable;
 	public abstract fun encode (Ljava/lang/String;)Ljava/lang/String;
 	public abstract fun getName ()Ljava/lang/String;
 }
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt
new file mode 100644
index 0000000000..b4588d9280
--- /dev/null
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ExpiringKeyedCache.kt
@@ -0,0 +1,42 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package aws.smithy.kotlin.runtime.collections
+
+import aws.smithy.kotlin.runtime.util.ExpiringValue
+
+/**
+ * A multi-value cache which supports retrieval and invalidation via a key paired with each value. The [get] and
+ * [invalidate] methods are `suspend` functions to allow for cross-context synchronization and potentially-expensive
+ * value lookup.
+ *
+ * Values in the cache _may_ expire and are retrieved as [ExpiringValue]. When a value is absent/expired in the cache,
+ * invoking [get] will cause a lookup to occur via the function's `valueLookup` parameter.
+ *
+ * @param K The type of the keys of this cache
+ * @param V The type of the values of this cache
+ */
+public interface ExpiringKeyedCache<K, V> {
+    /**
+     * The number of values currently stored in the cache
+     */
+    public val size: Int
+
+    /**
+     * Gets the value associated with this key from the cache. If the cache does not contain the given key,
+     * implementations are expected to invoke [valueLookup], although they _may_ perform other actions such as throw
+     * exceptions, fall back to other caches, etc.
+     * @param key The key for which to look up a value
+     * @param valueLookup A possibly-suspending function which returns the read-through value associated with a given
+     * key. This function is invoked when the cache does not contain the given [key] or when the value is expired.
+     */
+    public suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V
+
+    /**
+     * Invalidates the value (if any) for the given key, removing it from the cache regardless. This method has no
+     * effect if the given key is not present in the cache.
+     * @param key The key for which to invalidate a value
+     */
+    public suspend fun invalidate(key: K)
+}
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
similarity index 74%
rename from runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt
rename to runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
index 529a57d450..0940aaec2d 100644
--- a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/ReadThroughCache.kt
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/collections/PeriodicSweepCache.kt
@@ -12,8 +12,9 @@ import kotlinx.coroutines.sync.withLock
 import kotlin.time.Duration
 
 /**
- * An object which caches values and allows retrieving them by key. The values expire after a time. If a value is
- * expired or absent from the cache, it will be read from a `valueLookup` parameter passed to [get] and then cached.
+ * A cache which allows retrieving values by a key. Looking up a value for a key which does not exist in the cache (or
+ * where the value has expired) are resolved by calling [valueLookup]. The expiry for a value is included in the result
+ * returned from [valueLookup].
  *
  * A sweep operation will run prior to a [get] or [invalidate] that happens after [minimumSweepPeriod] has elapsed from
  * the last sweep (or from the initialization of the cache). This sweep will search for and remove expired entries from
@@ -29,10 +30,10 @@ import kotlin.time.Duration
  * @param clock The [Clock] to use for measuring time. Defaults to [Clock.System].
  */
 @InternalApi
-public class ReadThroughCache<K, V>(
+public class PeriodicSweepCache<K, V>(
     private val minimumSweepPeriod: Duration,
     private val clock: Clock = Clock.System,
-) {
+) : ExpiringKeyedCache<K, V> {
     private val map = mutableMapOf<K, ExpiringValue<V>>()
     private val mutex = Mutex()
     private var nextSweep = clock.now() + minimumSweepPeriod
@@ -44,7 +45,7 @@ public class ReadThroughCache<K, V>(
      * @param valueLookup A possibly-suspending function which returns the read-through value associated with a given
      * key. This function is invoked when the cache, for a given key, does not contain a value or the value is expired.
      */
-    public suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V = mutex.withLock {
+    override suspend fun get(key: K, valueLookup: suspend (K) -> ExpiringValue<V>): V = mutex.withLock {
         if (clock.now() > nextSweep) sweep()
 
         val current = map[key]
@@ -59,20 +60,29 @@ public class ReadThroughCache<K, V>(
      * Invalidates the value (if any) for the given key, removing it from the cache regardless of its expiry.
      * @param key The key for which to invalidate a value.
      */
-    public suspend fun invalidate(key: K): Unit = mutex.withLock {
+    override suspend fun invalidate(key: K): Unit = mutex.withLock {
         map.remove(key)
         if (clock.now() > nextSweep) sweep()
     }
 
+    /**
+     * Indicates whether this value is expired according to its [ExpiringValue.expiresAt] property and the cache's
+     * [clock]
+     */
     private val ExpiringValue<*>.isExpired: Boolean
         get() = clock.now() >= expiresAt
 
     /**
-     * Gets the number of values currently stored in the cache.
+     * Gets the number of values currently stored in the cache. Note that this property is non-volatile and may reflect
+     * stale information in highly-concurrent scenarios.
      */
-    public val size: Int
+    override val size: Int
         get() = map.size
 
+    /**
+     * Sweeps the cache to remove expired entries and schedule the next sweep. This method _must_ be invoked under mutex
+     * lock.
+     */
     private fun sweep() {
         val iterator = map.iterator()
         while (iterator.hasNext()) {
diff --git a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
index 3da3bb8c23..9cab81bdbc 100644
--- a/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
+++ b/runtime/runtime-core/common/src/aws/smithy/kotlin/runtime/smoketests/SmokeTestsFunctions.kt
@@ -2,27 +2,6 @@ package aws.smithy.kotlin.runtime.smoketests
 
 public expect fun exitProcess(status: Int): Nothing
 
-/**
- * Prints an exceptions stack trace using test anything protocol (TAP) format e.g.
- *
- * #java.lang.ArithmeticException: / by zero
- * #	at FileKt.main(File.kt:3)
- * #	at FileKt.main(File.kt)
- * #	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
- * #	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
- * #	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
- * #	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
- * #	at executors.JavaRunnerExecutor$Companion.main(JavaRunnerExecutor.kt:27)
- * #	at executors.JavaRunnerExecutor.main(JavaRunnerExecutor.kt)
- */
-@Deprecated(
-    message = "No longer used, target for removal in 1.5",
-    replaceWith = ReplaceWith("println(exception.stackTraceToString().prependIndent(\"#\"))"),
-    level = DeprecationLevel.WARNING,
-)
-public fun printExceptionStackTrace(exception: Exception): Unit =
-    println(exception.stackTraceToString().split("\n").joinToString("\n") { "#$it" })
-
 public class SmokeTestsException(message: String) : Exception(message)
 
 /**
diff --git a/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt b/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
similarity index 91%
rename from runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt
rename to runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
index 4d85ece15f..f070669c1f 100644
--- a/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/ReadThroughCacheTest.kt
+++ b/runtime/runtime-core/common/test/aws/smithy/kotlin/runtime/collections/PeriodicSweepCacheTest.kt
@@ -12,13 +12,13 @@ import kotlin.test.assertEquals
 import kotlin.time.Duration.Companion.minutes
 import kotlin.time.Duration.Companion.seconds
 
-class ReadThroughCacheTest {
+class PeriodicSweepCacheTest {
     @Test
-    fun testReadThrough() = runTest {
+    fun testGet() = runTest {
         val clock = ManualClock()
         var counter = 0
         fun uncachedValue() = ExpiringValue(counter++, clock.now() + 2.seconds)
-        val cache = ReadThroughCache<String, Int>(1.minutes, clock)
+        val cache = PeriodicSweepCache<String, Int>(1.minutes, clock)
 
         // Basic read through
         assertEquals(0, cache.get("a") { uncachedValue() })
@@ -41,7 +41,7 @@ class ReadThroughCacheTest {
         val clock = ManualClock()
         var counter = 0
         fun uncachedValue() = ExpiringValue(counter++, clock.now() + 2.seconds)
-        val cache = ReadThroughCache<String, Int>(4.seconds, clock)
+        val cache = PeriodicSweepCache<String, Int>(4.seconds, clock)
 
         // Pre-populate values
         assertEquals(0, cache.get("a") { uncachedValue() })
diff --git a/runtime/serde/serde-xml/api/serde-xml.api b/runtime/serde/serde-xml/api/serde-xml.api
index 736408bd97..eabc8febb8 100644
--- a/runtime/serde/serde-xml/api/serde-xml.api
+++ b/runtime/serde/serde-xml/api/serde-xml.api
@@ -47,16 +47,6 @@ public final class aws/smithy/kotlin/runtime/serde/xml/XmlCollectionValueNamespa
 	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 }
 
-public final class aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer : aws/smithy/kotlin/runtime/serde/Deserializer {
-	public fun <init> (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;Z)V
-	public synthetic fun <init> (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;ZILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public fun <init> ([BZ)V
-	public synthetic fun <init> ([BZILkotlin/jvm/internal/DefaultConstructorMarker;)V
-	public fun deserializeList (Laws/smithy/kotlin/runtime/serde/SdkFieldDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$ElementIterator;
-	public fun deserializeMap (Laws/smithy/kotlin/runtime/serde/SdkFieldDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$EntryIterator;
-	public fun deserializeStruct (Laws/smithy/kotlin/runtime/serde/SdkObjectDescriptor;)Laws/smithy/kotlin/runtime/serde/Deserializer$FieldIterator;
-}
-
 public final class aws/smithy/kotlin/runtime/serde/xml/XmlError : aws/smithy/kotlin/runtime/serde/FieldTrait {
 	public static final field INSTANCE Laws/smithy/kotlin/runtime/serde/xml/XmlError;
 	public final fun getErrorTag ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken$QualifiedName;
@@ -155,8 +145,10 @@ public abstract interface class aws/smithy/kotlin/runtime/serde/xml/XmlStreamRea
 	public abstract fun getLastToken ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun nextToken ()Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun peek (I)Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
+	public static synthetic fun peek$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;IILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlToken;
 	public abstract fun skipNext ()V
 	public abstract fun subTreeReader (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$SubtreeStartDepth;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;
+	public static synthetic fun subTreeReader$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$SubtreeStartDepth;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamReader;
 }
 
 public final class aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader$DefaultImpls {
@@ -178,13 +170,17 @@ public final class aws/smithy/kotlin/runtime/serde/xml/XmlStreamReaderKt {
 
 public abstract interface class aws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter {
 	public abstract fun attribute (Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun attribute$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun endDocument ()V
 	public abstract fun endTag (Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun endTag$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun getBytes ()[B
 	public abstract fun getText ()Ljava/lang/String;
 	public abstract fun namespacePrefix (Ljava/lang/String;Ljava/lang/String;)V
+	public static synthetic fun namespacePrefix$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)V
 	public abstract fun startDocument ()V
 	public abstract fun startTag (Ljava/lang/String;Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
+	public static synthetic fun startTag$default (Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;Ljava/lang/String;Ljava/lang/String;ILjava/lang/Object;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 	public abstract fun text (Ljava/lang/String;)Laws/smithy/kotlin/runtime/serde/xml/XmlStreamWriter;
 }
 
diff --git a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt
deleted file mode 100644
index b950e888b6..0000000000
--- a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlDeserializer.kt
+++ /dev/null
@@ -1,431 +0,0 @@
-/*
- * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package aws.smithy.kotlin.runtime.serde.xml
-
-import aws.smithy.kotlin.runtime.InternalApi
-import aws.smithy.kotlin.runtime.content.BigDecimal
-import aws.smithy.kotlin.runtime.content.BigInteger
-import aws.smithy.kotlin.runtime.content.Document
-import aws.smithy.kotlin.runtime.serde.*
-import aws.smithy.kotlin.runtime.text.encoding.decodeBase64Bytes
-import aws.smithy.kotlin.runtime.time.Instant
-import aws.smithy.kotlin.runtime.time.TimestampFormat
-
-private const val FIRST_FIELD_INDEX: Int = 0
-
-// Represents aspects of SdkFieldDescriptor that are particular to the Xml format
-internal sealed class FieldLocation {
-    // specifies the mapping to a sdk field index
-    abstract val fieldIndex: Int
-
-    data class Text(override val fieldIndex: Int) : FieldLocation() // Xml nodes have only one associated Text element
-    data class Attribute(override val fieldIndex: Int, val names: Set<XmlToken.QualifiedName>) : FieldLocation()
-}
-
-/**
- * Provides a deserializer for XML documents
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param validateRootElement Flag indicating if the root XML document [XmlToken.BeginElement] should be validated against
- * the descriptor passed to [deserializeStruct]. This only affects the root element, not nested struct elements. Some
- * restXml based services DO NOT always send documents with a root element name that matches the shape ID name
- * (S3 in particular). This means there is nothing in the model that gives you enough information to validate the tag.
- */
-@Deprecated("XmlDeserializer is deprecated and will be removed in a future release")
-@InternalApi
-public class XmlDeserializer(
-    private val reader: XmlStreamReader,
-    private val validateRootElement: Boolean = false,
-) : Deserializer {
-
-    public constructor(input: ByteArray, validateRootElement: Boolean = false) : this(xmlStreamReader(input), validateRootElement)
-
-    private var firstStructCall = true
-
-    override fun deserializeStruct(descriptor: SdkObjectDescriptor): Deserializer.FieldIterator {
-        if (firstStructCall) {
-            if (!descriptor.hasTrait<XmlSerialName>()) throw DeserializationException("Top-level struct $descriptor requires a XmlSerialName trait but has none.")
-
-            firstStructCall = false
-
-            reader.nextToken() // Matching field descriptors to children tags so consume the start element of top-level struct
-
-            val structToken = if (descriptor.hasTrait<XmlError>()) {
-                reader.seek<XmlToken.BeginElement> { it.name == descriptor.expectTrait<XmlError>().errorTag }
-            } else {
-                reader.seek<XmlToken.BeginElement>()
-            } ?: throw DeserializationException("Could not find a begin element for new struct")
-
-            if (validateRootElement) {
-                descriptor.requireNameMatch(structToken.name.tag)
-            }
-        }
-
-        // Consume any remaining terminating tokens from previous deserialization
-        reader.seek<XmlToken.BeginElement>()
-
-        // Because attributes set on the root node of the struct, we must read the values before creating the subtree
-        val attribFields = reader.tokenAttributesToFieldLocations(descriptor)
-        val parentToken = if (reader.lastToken is XmlToken.BeginElement) {
-            reader.lastToken as XmlToken.BeginElement
-        } else {
-            throw DeserializationException("Expected last parsed token to be ${XmlToken.BeginElement::class} but was ${reader.lastToken}")
-        }
-
-        val unwrapped = descriptor.hasTrait<XmlUnwrappedOutput>()
-        return XmlStructDeserializer(descriptor, reader.subTreeReader(XmlStreamReader.SubtreeStartDepth.CURRENT), parentToken, attribFields, unwrapped)
-    }
-
-    override fun deserializeList(descriptor: SdkFieldDescriptor): Deserializer.ElementIterator {
-        val depth = when (descriptor.hasTrait<Flattened>()) {
-            true -> XmlStreamReader.SubtreeStartDepth.CURRENT
-            else -> XmlStreamReader.SubtreeStartDepth.CHILD
-        }
-
-        return XmlListDeserializer(reader.subTreeReader(depth), descriptor)
-    }
-
-    override fun deserializeMap(descriptor: SdkFieldDescriptor): Deserializer.EntryIterator {
-        val depth = when (descriptor.hasTrait<Flattened>()) {
-            true -> XmlStreamReader.SubtreeStartDepth.CURRENT
-            else -> XmlStreamReader.SubtreeStartDepth.CHILD
-        }
-
-        return XmlMapDeserializer(reader.subTreeReader(depth), descriptor)
-    }
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce Maps
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param descriptor associated [SdkFieldDescriptor] which represents the expected Map
- * @param primitiveDeserializer used to deserialize primitive values
- */
-internal class XmlMapDeserializer(
-    private val reader: XmlStreamReader,
-    private val descriptor: SdkFieldDescriptor,
-    private val primitiveDeserializer: PrimitiveDeserializer = XmlPrimitiveDeserializer(reader, descriptor),
-) : PrimitiveDeserializer by primitiveDeserializer,
-    Deserializer.EntryIterator {
-    private val mapTrait = descriptor.findTrait<XmlMapName>() ?: XmlMapName.Default
-
-    override fun hasNextEntry(): Boolean {
-        val compareTo = when (descriptor.hasTrait<Flattened>()) {
-            true -> descriptor.findTrait<XmlSerialName>()?.name ?: mapTrait.key // Prefer seeking to XmlSerialName if the trait exists
-            false -> mapTrait.entry
-        }
-
-        // Seek to either the XML serial name, entry, or key token depending on the flatness of the map and if the name trait is present
-        val nextEntryToken = when (descriptor.hasTrait<Flattened>()) {
-            true -> reader.peekSeek<XmlToken.BeginElement> { it.name.local == compareTo }
-            false -> reader.seek<XmlToken.BeginElement> { it.name.local == compareTo }
-        }
-
-        return nextEntryToken != null
-    }
-
-    override fun key(): String {
-        // Seek to the key begin token
-        reader.seek<XmlToken.BeginElement> { it.name.local == mapTrait.key }
-            ?: error("Unable to find key $mapTrait.key in $descriptor")
-
-        val keyValueToken = reader.takeNextAs<XmlToken.Text>()
-        reader.nextToken() // Consume the end wrapper
-
-        return keyValueToken.value ?: throw DeserializationException("Key unspecified in $descriptor")
-    }
-
-    override fun nextHasValue(): Boolean {
-        // Expect a begin and value (or another begin) token if Map entry has a value
-        val peekBeginToken = reader.peek(1) ?: throw DeserializationException("Unexpected termination of token stream in $descriptor")
-        val peekValueToken = reader.peek(2) ?: throw DeserializationException("Unexpected termination of token stream in $descriptor")
-
-        return peekBeginToken !is XmlToken.EndElement && peekValueToken !is XmlToken.EndElement
-    }
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce Lists
- *
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param descriptor associated [SdkFieldDescriptor] which represents the expected Map
- * @param primitiveDeserializer used to deserialize primitive values
- */
-internal class XmlListDeserializer(
-    private val reader: XmlStreamReader,
-    private val descriptor: SdkFieldDescriptor,
-    private val primitiveDeserializer: PrimitiveDeserializer = XmlPrimitiveDeserializer(reader, descriptor),
-) : PrimitiveDeserializer by primitiveDeserializer,
-    Deserializer.ElementIterator {
-    private var firstCall = true
-    private val flattened = descriptor.hasTrait<Flattened>()
-    private val elementName = (descriptor.findTrait<XmlCollectionName>() ?: XmlCollectionName.Default).element
-
-    override fun hasNextElement(): Boolean {
-        if (!flattened && firstCall) {
-            val nextToken = reader.peek()
-            val matchedListDescriptor = nextToken is XmlToken.BeginElement && descriptor.nameMatches(nextToken.name.tag)
-            val hasChildren = if (nextToken == null) false else nextToken.depth >= reader.lastToken!!.depth
-
-            if (!matchedListDescriptor && !hasChildren) return false
-
-            // Discard the wrapper and move to the first element in the list
-            if (matchedListDescriptor) reader.nextToken()
-
-            firstCall = false
-        }
-
-        if (flattened) {
-            // Because our subtree is not CHILD, we cannot rely on the subtree boundary to determine end of collection.
-            // Rather, we search for either the next begin token matching the (flat) list member name which should
-            // be immediately after the current token
-
-            // peek at the next token if there is one, in the case of a list of structs, the next token is actually
-            // the end of the current flat list element in which case we need to peek twice
-            val next = when (val peeked = reader.peek()) {
-                is XmlToken.EndElement -> {
-                    if (peeked.name.local == descriptor.serialName.name) {
-                        // consume the end token
-                        reader.nextToken()
-                        reader.peek()
-                    } else {
-                        peeked
-                    }
-                }
-                else -> peeked
-            }
-
-            val tokens = listOfNotNull(reader.lastToken, next)
-
-            // Iterate over the token stream until begin token matching name is found or end element matching list is found.
-            return tokens
-                .filterIsInstance<XmlToken.BeginElement>()
-                .any { it.name.local == descriptor.serialName.name }
-        } else {
-            // If we can find another begin token w/ the element name, we have more elements to process
-            return reader.seek<XmlToken.BeginElement> { it.name.local == elementName }.isNotTerminal()
-        }
-    }
-
-    override fun nextHasValue(): Boolean = reader.peek() !is XmlToken.EndElement
-}
-
-/**
- * Deserializes specific XML structures into forms that can produce structures
- *
- * @param objDescriptor associated [SdkObjectDescriptor] which represents the expected structure
- * @param reader underlying [XmlStreamReader] from which tokens are read
- * @param parentToken initial token of associated structure
- * @param parsedFieldLocations list of [FieldLocation] representing values able to be loaded into deserialized instances
- */
-private class XmlStructDeserializer(
-    private val objDescriptor: SdkObjectDescriptor,
-    reader: XmlStreamReader,
-    private val parentToken: XmlToken.BeginElement,
-    private val parsedFieldLocations: MutableList<FieldLocation> = mutableListOf(),
-    private val unwrapped: Boolean,
-) : Deserializer.FieldIterator {
-    // Used to track direct deserialization or further nesting between calls to findNextFieldIndex() and deserialize<Type>()
-    private var reentryFlag: Boolean = false
-
-    private val reader: XmlStreamReader = if (unwrapped) reader else reader.subTreeReader(XmlStreamReader.SubtreeStartDepth.CHILD)
-
-    override fun findNextFieldIndex(): Int? {
-        if (unwrapped) {
-            return if (reader.peek() is XmlToken.Text) FIRST_FIELD_INDEX else null
-        }
-        if (inNestedMode()) {
-            // Returning from a nested struct call.  Nested deserializer consumed
-            // tokens so clear them here to avoid processing stale state
-            parsedFieldLocations.clear()
-        }
-
-        if (parsedFieldLocations.isEmpty()) {
-            val matchedFieldLocations = when (val token = reader.nextToken()) {
-                null, is XmlToken.EndDocument -> return null
-                is XmlToken.EndElement -> return findNextFieldIndex()
-                is XmlToken.BeginElement -> {
-                    val nextToken = reader.peek() ?: return null
-                    val objectFields = objDescriptor.fields
-                    val memberFields = objectFields.filter { field -> objDescriptor.fieldTokenMatcher(field, token) }
-                    val matchingFields = memberFields.mapNotNull { it.findFieldLocation(token, nextToken) }
-                    matchingFields
-                }
-                else -> return findNextFieldIndex()
-            }
-
-            // Sorting ensures attribs are processed before text, as processing the Text token pushes the parser on to the next token.
-            parsedFieldLocations.addAll(matchedFieldLocations.sortedBy { it is FieldLocation.Text })
-        }
-
-        return parsedFieldLocations.firstOrNull()?.fieldIndex ?: Deserializer.FieldIterator.UNKNOWN_FIELD
-    }
-
-    private fun <T> deserializeValue(transform: ((String) -> T)): T {
-        if (unwrapped) {
-            val value = reader.takeNextAs<XmlToken.Text>().value ?: ""
-            return transform(value)
-        }
-        // Set and validate mode
-        reentryFlag = false
-        if (parsedFieldLocations.isEmpty()) throw DeserializationException("matchedFields is empty, was findNextFieldIndex() called?")
-
-        // Take the first FieldLocation and attempt to parse it into the value specified by the descriptor.
-        return when (val nextField = parsedFieldLocations.removeFirst()) {
-            is FieldLocation.Text -> {
-                val value = when (val peekToken = reader.peek()) {
-                    is XmlToken.Text -> reader.takeNextAs<XmlToken.Text>().value ?: ""
-                    is XmlToken.EndElement -> ""
-                    else -> throw DeserializationException("Unexpected token $peekToken")
-                }
-                transform(value)
-            }
-            is FieldLocation.Attribute -> {
-                transform(
-                    nextField
-                        .names
-                        .mapNotNull { parentToken.attributes[it] }
-                        .firstOrNull() ?: throw DeserializationException("Expected attrib value ${nextField.names.first()} not found in ${parentToken.name}"),
-                )
-            }
-        }
-    }
-
-    override fun skipValue() = reader.skipNext()
-
-    override fun deserializeByte(): Byte = deserializeValue { it.toIntOrNull()?.toByte() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeInt(): Int = deserializeValue { it.toIntOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeShort(): Short = deserializeValue { it.toIntOrNull()?.toShort() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeLong(): Long = deserializeValue { it.toLongOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeFloat(): Float = deserializeValue { it.toFloatOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeDouble(): Double = deserializeValue { it.toDoubleOrNull() ?: throw DeserializationException("Unable to deserialize $it") }
-
-    override fun deserializeBigInteger(): BigInteger = deserializeValue {
-        runCatching { BigInteger(it) }
-            .getOrElse { throw DeserializationException("Unable to deserialize $it as BigInteger") }
-    }
-
-    override fun deserializeBigDecimal(): BigDecimal = deserializeValue {
-        runCatching { BigDecimal(it) }
-            .getOrElse { throw DeserializationException("Unable to deserialize $it as BigDecimal") }
-    }
-
-    override fun deserializeString(): String = deserializeValue { it }
-
-    override fun deserializeBoolean(): Boolean = deserializeValue { it.toBoolean() }
-
-    override fun deserializeDocument(): Document = throw DeserializationException("cannot deserialize unsupported Document type in xml")
-
-    override fun deserializeByteArray(): ByteArray = deserializeString().decodeBase64Bytes()
-
-    override fun deserializeInstant(format: TimestampFormat): Instant = when (format) {
-        TimestampFormat.EPOCH_SECONDS -> deserializeString().let { Instant.fromEpochSeconds(it) }
-        TimestampFormat.ISO_8601 -> deserializeString().let { Instant.fromIso8601(it) }
-        TimestampFormat.RFC_5322 -> deserializeString().let { Instant.fromRfc5322(it) }
-        else -> throw DeserializationException("unknown timestamp format: $format")
-    }
-
-    override fun deserializeNull(): Nothing? {
-        reader.takeNextAs<XmlToken.EndElement>()
-        return null
-    }
-
-    // A struct deserializer can be called in two "modes":
-    // 1. to deserialize a value.  This calls findNextFieldIndex() followed by deserialize<SomePrimitiveType>()
-    // 2. to deserialize a nested container. This calls findNextFieldIndex() followed by a call to another deserialize<Struct/List/Map>()
-    // Because state is built in findNextFieldIndex() that is intended to be used directly in deserialize<SomePrimitiveType>() (mode 1)
-    // and there is no explicit way that this type knows which mode is in use, the state built must be cleared.
-    // this is done by flipping a bit between the two calls.  If the bit has not been flipped on any call to findNextFieldIndex()
-    // it is determined that the nested mode was used and any existing state should be cleared.
-    // if the state is not cleared, deserialization goes into an infinite loop because the deserializer sees pending fields to pull from the stream
-    // which are never consumed by the (missing) call to deserialize<SomePrimitiveType>()
-    private fun inNestedMode(): Boolean = when (reentryFlag) {
-        true -> true
-        false -> {
-            reentryFlag = true
-            false
-        }
-    }
-}
-
-// Extract the attributes from the last-read token and match them to [FieldLocation] on the [SdkObjectDescriptor].
-private fun XmlStreamReader.tokenAttributesToFieldLocations(descriptor: SdkObjectDescriptor): MutableList<FieldLocation> =
-    if (descriptor.hasXmlAttributes && lastToken is XmlToken.BeginElement) {
-        val attribFields = descriptor.fields.filter { it.hasTrait<XmlAttribute>() }
-        val matchedAttribFields = attribFields.filter { it.findFieldLocation(lastToken as XmlToken.BeginElement, peek() ?: throw DeserializationException("Unexpected end of tokens")) != null }
-        matchedAttribFields.map { FieldLocation.Attribute(it.index, it.toQualifiedNames()) }
-            .toMutableList()
-    } else {
-        mutableListOf()
-    }
-
-// Returns a [FieldLocation] if the field maps to the current token
-private fun SdkFieldDescriptor.findFieldLocation(
-    currentToken: XmlToken.BeginElement,
-    nextToken: XmlToken,
-): FieldLocation? = when (val property = toFieldLocation()) {
-    is FieldLocation.Text -> {
-        when {
-            nextToken is XmlToken.Text -> property
-            nextToken is XmlToken.BeginElement -> property
-            // The following allows for struct primitives to remain unvisited if no value
-            // but causes nested deserializers to be called even if they contain no value
-            nextToken is XmlToken.EndElement && currentToken.name == nextToken.name -> property
-            else -> null
-        }
-    }
-    is FieldLocation.Attribute -> {
-        val foundMatch = property.names.any { currentToken.attributes[it]?.isNotBlank() == true }
-        if (foundMatch) property else null
-    }
-}
-
-// Produce a [FieldLocation] type based on presence of traits of field
-// A field without an attribute trait is assumed to be a text token
-private fun SdkFieldDescriptor.toFieldLocation(): FieldLocation =
-    when (findTrait<XmlAttribute>()) {
-        null -> FieldLocation.Text(index) // Assume a text value if no attributes defined.
-        else -> FieldLocation.Attribute(index, toQualifiedNames())
-    }
-
-// Matches fields and tokens with matching qualified name
-private fun SdkObjectDescriptor.fieldTokenMatcher(fieldDescriptor: SdkFieldDescriptor, beginElement: XmlToken.BeginElement): Boolean {
-    if (fieldDescriptor.kind == SerialKind.List && fieldDescriptor.hasTrait<Flattened>()) {
-        val fieldName = fieldDescriptor.findTrait<XmlCollectionName>() ?: XmlCollectionName.Default
-        val tokenQname = beginElement.name
-
-        // It may be that we are matching a flattened list element or matching a list itself.  In the latter
-        // case the following predicate will not work, so if we fail to match the member
-        // try again (below) to match against the container.
-        if (fieldName.element == tokenQname.local) return true
-    }
-
-    return fieldDescriptor.nameMatches(beginElement.name.tag)
-}
-
-/**
- * Return the next token of the specified type or throw [DeserializationException] if incorrect type.
- */
-internal inline fun <reified TExpected : XmlToken> XmlStreamReader.takeNextAs(): TExpected {
-    val token = this.nextToken() ?: throw DeserializationException("Expected ${TExpected::class} but instead found null")
-    requireToken<TExpected>(token)
-    return token as TExpected
-}
-
-/**
- * Require that the given token be of type [TExpected] or else throw an exception
- */
-internal inline fun <reified TExpected> requireToken(token: XmlToken) {
-    if (token::class != TExpected::class) {
-        throw DeserializationException("Expected ${TExpected::class}; found ${token::class} ($token)")
-    }
-}
diff --git a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
index a43250b267..760f52a833 100644
--- a/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
+++ b/runtime/serde/serde-xml/common/src/aws/smithy/kotlin/runtime/serde/xml/XmlStreamReader.kt
@@ -6,6 +6,7 @@
 package aws.smithy.kotlin.runtime.serde.xml
 
 import aws.smithy.kotlin.runtime.InternalApi
+import aws.smithy.kotlin.runtime.serde.DeserializationException
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.LexingXmlStreamReader
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.StringTextStream
 import aws.smithy.kotlin.runtime.serde.xml.deserialization.XmlLexer
@@ -114,6 +115,24 @@ public inline fun <reified T : XmlToken> XmlStreamReader.peekSeek(selectionPredi
     return null
 }
 
+/**
+ * Return the next token of the specified type or throw [DeserializationException] if incorrect type.
+ */
+internal inline fun <reified TExpected : XmlToken> XmlStreamReader.takeNextAs(): TExpected {
+    val token = this.nextToken() ?: throw DeserializationException("Expected ${TExpected::class} but instead found null")
+    requireToken<TExpected>(token)
+    return token as TExpected
+}
+
+/**
+ * Require that the given token be of type [TExpected] or else throw an exception
+ */
+private inline fun <reified TExpected> requireToken(token: XmlToken) {
+    if (token::class != TExpected::class) {
+        throw DeserializationException("Expected ${TExpected::class}; found ${token::class} ($token)")
+    }
+}
+
 /**
  * Creates an [XmlStreamReader] instance
  */
diff --git a/runtime/smithy-client/api/smithy-client.api b/runtime/smithy-client/api/smithy-client.api
index b6132b26b8..823ff0467d 100644
--- a/runtime/smithy-client/api/smithy-client.api
+++ b/runtime/smithy-client/api/smithy-client.api
@@ -30,47 +30,25 @@ public final class aws/smithy/kotlin/runtime/client/IdempotencyTokenProvider$Com
 }
 
 public abstract interface class aws/smithy/kotlin/runtime/client/Interceptor {
-	public abstract fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public abstract fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterExecution (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public abstract fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readAfterSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public abstract fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public abstract fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public abstract fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public abstract fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public abstract fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-}
-
-public final class aws/smithy/kotlin/runtime/client/Interceptor$DefaultImpls {
-	public static fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
-	public static fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterExecution (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
-	public static fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readAfterSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public static fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
-	public static fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public static fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
-	public static fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
-	public static fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/Interceptor;Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun modifyBeforeAttemptCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeCompletion-gIAlu-s (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeRetryLoop (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun modifyBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun readAfterAttempt (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterDeserialization (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterExecution (Laws/smithy/kotlin/runtime/client/ResponseInterceptorContext;)V
+	public fun readAfterSerialization (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readAfterSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readAfterTransmit (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
+	public fun readBeforeAttempt (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readBeforeDeserialization (Laws/smithy/kotlin/runtime/client/ProtocolResponseInterceptorContext;)V
+	public fun readBeforeExecution (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
+	public fun readBeforeSerialization (Laws/smithy/kotlin/runtime/client/RequestInterceptorContext;)V
+	public fun readBeforeSigning (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
+	public fun readBeforeTransmit (Laws/smithy/kotlin/runtime/client/ProtocolRequestInterceptorContext;)V
 }
 
 public abstract class aws/smithy/kotlin/runtime/client/LogMode {
@@ -187,7 +165,7 @@ public abstract interface class aws/smithy/kotlin/runtime/client/SdkClientConfig
 
 public abstract interface class aws/smithy/kotlin/runtime/client/SdkClientFactory {
 	public abstract fun builder ()Laws/smithy/kotlin/runtime/client/SdkClient$Builder;
-	public abstract fun invoke (Lkotlin/jvm/functions/Function1;)Laws/smithy/kotlin/runtime/client/SdkClient;
+	public fun invoke (Lkotlin/jvm/functions/Function1;)Laws/smithy/kotlin/runtime/client/SdkClient;
 }
 
 public final class aws/smithy/kotlin/runtime/client/SdkClientFactory$DefaultImpls {
@@ -225,7 +203,7 @@ public abstract interface class aws/smithy/kotlin/runtime/client/config/Compress
 
 public abstract interface class aws/smithy/kotlin/runtime/client/config/CompressionClientConfig$Builder {
 	public abstract fun getRequestCompression ()Laws/smithy/kotlin/runtime/client/config/RequestCompressionConfig$Builder;
-	public abstract fun requestCompression (Lkotlin/jvm/functions/Function1;)V
+	public fun requestCompression (Lkotlin/jvm/functions/Function1;)V
 }
 
 public final class aws/smithy/kotlin/runtime/client/config/CompressionClientConfig$Builder$DefaultImpls {
@@ -353,3 +331,15 @@ public final class aws/smithy/kotlin/runtime/client/endpoints/functions/Url {
 	public fun toString ()Ljava/lang/String;
 }
 
+public abstract interface class aws/smithy/kotlin/runtime/client/region/RegionProvider {
+	public abstract fun getRegion (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public class aws/smithy/kotlin/runtime/client/region/RegionProviderChain : aws/smithy/kotlin/runtime/client/region/RegionProvider {
+	public fun <init> (Ljava/util/List;)V
+	public fun <init> ([Laws/smithy/kotlin/runtime/client/region/RegionProvider;)V
+	protected final fun getProviders ()[Laws/smithy/kotlin/runtime/client/region/RegionProvider;
+	public fun getRegion (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun toString ()Ljava/lang/String;
+}
+
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
index 8d2b5c68bc..4fab16b9a7 100644
--- a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/Interceptor.kt
@@ -5,6 +5,7 @@
 
 package aws.smithy.kotlin.runtime.client
 
+import aws.smithy.kotlin.runtime.client.util.MpJvmDefaultWithoutCompatibility
 import aws.smithy.kotlin.runtime.operation.ExecutionContext
 
 /**
@@ -20,6 +21,7 @@ import aws.smithy.kotlin.runtime.operation.ExecutionContext
  * **MUST** not modify state even if it is possible to do so (it is not always possible or performant to provide an
  * immutable view of every type).
  */
+@MpJvmDefaultWithoutCompatibility
 public interface Interceptor<
     Input,
     Output,
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt
new file mode 100644
index 0000000000..9e82ec4509
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProvider.kt
@@ -0,0 +1,17 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+/**
+ * Interface for providing AWS region information. Implementations are free to use any strategy for
+ * providing region information
+ */
+public interface RegionProvider {
+    /**
+     * Return the region name to use. If region information is not available, implementations should return null
+     */
+    public suspend fun getRegion(): String?
+}
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt
new file mode 100644
index 0000000000..0df388d11f
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/region/RegionProviderChain.kt
@@ -0,0 +1,52 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+import aws.smithy.kotlin.runtime.telemetry.logging.logger
+import aws.smithy.kotlin.runtime.util.asyncLazy
+import kotlin.coroutines.coroutineContext
+
+/**
+ * Composite [RegionProvider] that delegates to a chain of providers.
+ * [providers] are consulted in the order given and the first region found is returned
+ *
+ * @param providers the list of providers to delegate to
+ */
+public open class RegionProviderChain(
+    protected vararg val providers: RegionProvider,
+) : RegionProvider {
+
+    public constructor(providers: List<RegionProvider>) : this(*providers.toTypedArray())
+
+    private val resolvedRegion = asyncLazy(::resolveRegion)
+
+    init {
+        require(providers.isNotEmpty()) { "at least one provider must be in the chain" }
+    }
+
+    override fun toString(): String =
+        (listOf(this) + providers).map { it::class.simpleName }.joinToString(" -> ")
+
+    override suspend fun getRegion(): String? = resolvedRegion.get()
+
+    private suspend fun resolveRegion(): String? {
+        val logger = coroutineContext.logger<RegionProviderChain>()
+        for (provider in providers) {
+            try {
+                val region = provider.getRegion()
+                if (region != null) {
+                    logger.debug { "resolved region ($region) from $provider " }
+                    return region
+                }
+                logger.debug { "failed to resolve region from $provider" }
+            } catch (ex: Exception) {
+                logger.debug { "unable to load region from $provider: ${ex.message}" }
+            }
+        }
+
+        return null
+    }
+}
diff --git a/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt
new file mode 100644
index 0000000000..f7b9449ebc
--- /dev/null
+++ b/runtime/smithy-client/common/src/aws/smithy/kotlin/runtime/client/util/Annotations.kt
@@ -0,0 +1,13 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+/**
+ * A KMP-compatible variant of [kotlin.jvm.JvmDefaultWithoutCompatibility]
+ */
+@Retention(AnnotationRetention.SOURCE)
+@Target(AnnotationTarget.CLASS)
+public expect annotation class MpJvmDefaultWithoutCompatibility()
diff --git a/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt b/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt
new file mode 100644
index 0000000000..361336ac2d
--- /dev/null
+++ b/runtime/smithy-client/common/test/aws/smithy/kotlin/runtime/client/region/RegionProviderChainTest.kt
@@ -0,0 +1,47 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.region
+
+import kotlinx.coroutines.test.runTest
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+
+class RegionProviderChainTest {
+    @Test
+    fun testNoProviders() {
+        assertFails("at least one provider") {
+            RegionProviderChain()
+        }
+    }
+    data class TestProvider(val region: String? = null) : RegionProvider {
+        override suspend fun getRegion(): String? = region
+    }
+
+    @Test
+    fun testChain() = runTest {
+        val chain = RegionProviderChain(
+            TestProvider(null),
+            TestProvider("us-east-1"),
+            TestProvider("us-east-2"),
+        )
+
+        assertEquals("us-east-1", chain.getRegion())
+    }
+
+    @Test
+    fun testChainList() = runTest {
+        val providers = listOf<RegionProvider>(
+            TestProvider(null),
+            TestProvider("us-east-1"),
+            TestProvider("us-east-2"),
+        )
+
+        val chain = RegionProviderChain(providers)
+
+        assertEquals("us-east-1", chain.getRegion())
+    }
+}
diff --git a/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt b/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt
new file mode 100644
index 0000000000..db7512a9df
--- /dev/null
+++ b/runtime/smithy-client/jvm/src/aws/smithy/kotlin/runtime/client/util/AnnotationsJVM.kt
@@ -0,0 +1,8 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+public actual typealias MpJvmDefaultWithoutCompatibility = kotlin.jvm.JvmDefaultWithoutCompatibility
diff --git a/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt b/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt
new file mode 100644
index 0000000000..118ea69bda
--- /dev/null
+++ b/runtime/smithy-client/native/src/aws/smithy/kotlin/runtime/client/util/AnnotationsNative.kt
@@ -0,0 +1,10 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package aws.smithy.kotlin.runtime.client.util
+
+public actual annotation class MpJvmDefaultWithoutCompatibility {
+    // No-op on non-JVM platforms
+}
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 2c8d3df112..2738eb0d29 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -120,6 +120,7 @@ include(":tests:codegen:paginator-tests")
 include(":tests:codegen:serde-tests")
 include(":tests:codegen:serde-codegen-support")
 include(":tests:codegen:waiter-tests")
+include(":tests:codegen:service-codegen-tests")
 include(":tests:integration:slf4j-1x-consumer")
 include(":tests:integration:slf4j-2x-consumer")
 include(":tests:integration:slf4j-hybrid-consumer")
diff --git a/tests/codegen/service-codegen-tests/build.gradle.kts b/tests/codegen/service-codegen-tests/build.gradle.kts
new file mode 100644
index 0000000000..a7d734d896
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/build.gradle.kts
@@ -0,0 +1,72 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+import aws.sdk.kotlin.gradle.dsl.skipPublishing
+
+plugins {
+    id(libs.plugins.kotlin.jvm.get().pluginId)
+    alias(libs.plugins.kotlinx.serialization)
+    alias(libs.plugins.aws.kotlin.repo.tools.smithybuild)
+}
+
+skipPublishing()
+
+val optinAnnotations = listOf("kotlin.RequiresOptIn")
+kotlin.sourceSets.all {
+    optinAnnotations.forEach { languageSettings.optIn(it) }
+}
+
+// Create a task to run the DefaultServiceGeneratorTestKt file
+val runServiceGenerator by tasks.registering(JavaExec::class) {
+    group = "verification"
+    description = "Run the DefaultServiceGeneratorTestKt file"
+    classpath = sourceSets["main"].runtimeClasspath
+    mainClass.set("com.test.DefaultServiceGeneratorTestKt")
+}
+
+tasks.test {
+    dependsOn(runServiceGenerator)
+    useJUnitPlatform()
+    testLogging {
+        events("passed", "skipped", "failed")
+        showStandardStreams = true
+    }
+}
+
+kotlin {
+    compilerOptions {
+        freeCompilerArgs.addAll(
+            "-opt-in=kotlin.io.path.ExperimentalPathApi",
+            "-opt-in=kotlinx.serialization.ExperimentalSerializationApi",
+        )
+    }
+}
+
+dependencies {
+
+    compileOnly(project(":codegen:smithy-kotlin-codegen"))
+
+    implementation(project(":codegen:smithy-kotlin-codegen"))
+    implementation(project(":codegen:smithy-aws-kotlin-codegen"))
+    implementation(project(":codegen:smithy-kotlin-codegen-testutils"))
+
+    implementation(libs.kotlinx.serialization.json)
+    implementation(libs.kotlinx.serialization.cbor)
+
+    testImplementation(libs.junit.jupiter)
+    testImplementation(libs.kotest.assertions.core.jvm)
+    testImplementation(libs.kotlin.test)
+    testImplementation(libs.kotlin.test.junit5)
+    testImplementation(project(":codegen:smithy-kotlin-codegen-testutils"))
+    testImplementation(project(":codegen:smithy-kotlin-codegen"))
+    testImplementation(project(":codegen:smithy-aws-kotlin-codegen"))
+    testApi(project(":runtime:auth:aws-signing-common"))
+    testApi(project(":runtime:auth:http-auth-aws"))
+    testApi(project(":runtime:auth:aws-signing-default"))
+
+    testImplementation(gradleTestKit())
+
+    testImplementation(libs.kotlinx.serialization.json)
+    testImplementation(libs.kotlinx.serialization.cbor)
+}
diff --git a/tests/codegen/service-codegen-tests/model/service-authentication-test.smithy b/tests/codegen/service-codegen-tests/model/service-authentication-test.smithy
new file mode 100644
index 0000000000..3d3a5dc117
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/model/service-authentication-test.smithy
@@ -0,0 +1,122 @@
+$version: "2.0"
+
+namespace com.authentication
+
+use smithy.api#httpBearerAuth
+use aws.auth#sigv4
+use aws.auth#sigv4a
+use aws.protocols#restJson1
+
+@restJson1
+@auth([sigv4a, sigv4, httpBearerAuth])
+@httpBearerAuth
+@sigv4(name: "service-1")
+@sigv4a(name: "service-1")
+service AuthenticationServiceTest {
+    version: "1.0.0"
+    operations: [
+        OnlyBearerTest
+        OnlySigV4Test
+        SigV4ATest
+        AllAuthenticationTest
+        NoAuthenticationTest
+        SigV4AuthenticationWithBodyTest
+        SigV4AAuthenticationWithBodyTest
+    ]
+}
+
+@auth([httpBearerAuth])
+@http(method: "POST", uri: "/only-bearer", code: 201)
+operation OnlyBearerTest {
+    input: OnlyBearerTestInput
+    output: OnlyBearerTestOutput
+}
+
+@input
+structure OnlyBearerTestInput {}
+
+@output
+structure OnlyBearerTestOutput {}
+
+@auth([sigv4])
+@http(method: "POST", uri: "/only-sigv4", code: 201)
+operation OnlySigV4Test {
+    input: OnlySigV4TestInput
+    output: OnlySigV4TestOutput
+}
+
+@input
+structure OnlySigV4TestInput {}
+
+@output
+structure OnlySigV4TestOutput {}
+
+@auth([sigv4a, sigv4])
+@http(method: "POST", uri: "/sigv4a", code: 201)
+operation SigV4ATest {
+    input: SigV4ATestInput
+    output: SigV4ATestOutput
+}
+
+@input
+structure SigV4ATestInput {}
+
+@output
+structure SigV4ATestOutput {}
+
+@http(method: "POST", uri: "/all-authentication", code: 201)
+operation AllAuthenticationTest {
+    input: AllAuthenticationTestInput
+    output: AllAuthenticationTestOutput
+}
+
+@input
+structure AllAuthenticationTestInput {}
+
+@output
+structure AllAuthenticationTestOutput {}
+
+@auth([])
+@http(method: "POST", uri: "/no-authentication", code: 201)
+operation NoAuthenticationTest {
+    input: NoAuthenticationTestInput
+    output: NoAuthenticationTestOutput
+}
+
+@input
+structure NoAuthenticationTestInput {}
+
+@output
+structure NoAuthenticationTestOutput {}
+
+@auth([sigv4])
+@http(method: "POST", uri: "/sigv4-authentication-body", code: 201)
+operation SigV4AuthenticationWithBodyTest {
+    input: SigV4AuthenticationWithBodyTestInput
+    output: SigV4AuthenticationWithBodyTestOutput
+}
+
+@input
+structure SigV4AuthenticationWithBodyTestInput {
+    input1: String
+}
+
+@output
+structure SigV4AuthenticationWithBodyTestOutput {}
+
+
+@auth([sigv4a, sigv4])
+@http(method: "POST", uri: "/sigv4a-authentication-body", code: 201)
+operation SigV4AAuthenticationWithBodyTest {
+    input: SigV4AAuthenticationWithBodyTestInput
+    output: SigV4AAuthenticationWithBodyTestOutput
+}
+
+@input
+structure SigV4AAuthenticationWithBodyTestInput {
+    input1: String
+}
+
+@output
+structure SigV4AAuthenticationWithBodyTestOutput {}
+
diff --git a/tests/codegen/service-codegen-tests/model/service-cbor-test.smithy b/tests/codegen/service-codegen-tests/model/service-cbor-test.smithy
new file mode 100644
index 0000000000..90314f61e8
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/model/service-cbor-test.smithy
@@ -0,0 +1,87 @@
+$version: "2.0"
+
+namespace com.cbor
+
+use smithy.protocols#rpcv2Cbor
+
+@rpcv2Cbor
+service CborServiceTest {
+    version: "1.0.0"
+    operations: [
+        PostTest
+        AuthTest
+        ErrorTest
+        HttpErrorTest
+    ]
+}
+
+@http(method: "POST", uri: "/post", code: 201)
+operation PostTest {
+    input: PostTestInput
+    output: PostTestOutput
+}
+
+@input
+structure PostTestInput {
+    input1: String
+    input2: Integer
+}
+
+@output
+structure PostTestOutput {
+    output1: String
+    output2: Integer
+}
+
+@http(method: "POST", uri: "/auth", code: 201)
+operation AuthTest {
+    input: AuthTestInput
+    output: AuthTestOutput
+}
+
+@input
+structure AuthTestInput {
+    input1: String
+}
+
+@output
+structure AuthTestOutput {
+    output1: String
+}
+
+@http(method: "POST", uri: "/error", code: 200)
+operation ErrorTest {
+    input: ErrorTestInput
+    output: ErrorTestOutput
+}
+
+@input
+structure ErrorTestInput {
+    input1: String
+}
+
+@output
+structure ErrorTestOutput {
+    output1: String
+}
+
+
+@http(method: "POST", uri: "/http-error", code: 200)
+operation HttpErrorTest {
+    input: HttpErrorTestInput
+    output: HttpErrorTestOutput
+    errors: [HttpError]
+}
+
+@input
+structure HttpErrorTestInput {}
+
+@output
+structure HttpErrorTestOutput {}
+
+@error("client")
+@httpError(456)
+structure HttpError {
+    msg: String
+    num: Integer
+}
\ No newline at end of file
diff --git a/tests/codegen/service-codegen-tests/model/service-constraints-test.smithy b/tests/codegen/service-codegen-tests/model/service-constraints-test.smithy
new file mode 100644
index 0000000000..51cacdfedd
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/model/service-constraints-test.smithy
@@ -0,0 +1,165 @@
+$version: "2.0"
+
+namespace com.constraints
+
+use smithy.protocols#rpcv2Cbor
+
+@rpcv2Cbor
+service ServiceConstraintsTest {
+    version: "1.0.0"
+    operations: [
+        RequiredConstraintTest,
+        LengthConstraintTest,
+        PatternConstraintTest,
+        RangeConstraintTest,
+        UniqueItemsConstraintTest,
+        NestedUniqueItemsConstraintTest,
+        DoubleNestedUniqueItemsConstraintTest,
+    ]
+}
+
+@http(method: "POST", uri: "/required-constraint", code: 201)
+operation RequiredConstraintTest {
+    input: RequiredConstraintTestInput
+    output: RequiredConstraintTestOutput
+}
+
+@input
+structure RequiredConstraintTestInput {
+    @required
+    requiredInput: String
+    notRequiredInput: String
+}
+
+@output
+structure RequiredConstraintTestOutput {}
+
+@http(method: "POST", uri: "/length-constraint", code: 201)
+operation LengthConstraintTest {
+    input: LengthConstraintTestInput
+    output: LengthConstraintTestOutput
+}
+
+@input
+structure LengthConstraintTestInput {
+    @length(min: 3)
+    greaterLengthInput: String
+
+    @length(max: 3)
+    smallerLengthInput: NotUniqueItemsList
+
+    @length(min: 1, max: 2)
+    betweenLengthInput: MyMap
+}
+
+@output
+structure LengthConstraintTestOutput {}
+
+@http(method: "POST", uri: "/pattern-constraint", code: 201)
+operation PatternConstraintTest {
+    input: PatternConstraintTestInput
+    output: PatternConstraintTestOutput
+}
+
+@input
+structure PatternConstraintTestInput {
+    @pattern("^[A-Za-z]+$")
+    patternInput1: String
+
+    @pattern("[1-9]+")
+    patternInput2: String
+
+
+}
+
+@output
+structure PatternConstraintTestOutput {}
+
+
+@http(method: "POST", uri: "/range-constraint", code: 201)
+operation RangeConstraintTest {
+    input: RangeConstraintTestInput
+    output: RangeConstraintTestOutput
+}
+
+@input
+structure RangeConstraintTestInput {
+    @range(min: 0, max: 5)
+    betweenInput: Integer
+
+    @range(min: -10)
+    greaterInput: Double
+
+    @range(max: 9)
+    smallerInput: Float
+}
+
+@output
+structure RangeConstraintTestOutput {}
+
+@http(method: "POST", uri: "/unique-items-constraint", code: 201)
+operation UniqueItemsConstraintTest {
+    input: UniqueItemsConstraintTestInput
+    output: UniqueItemsConstraintTestOutput
+}
+
+@input
+structure UniqueItemsConstraintTestInput {
+    notUniqueItemsListInput: NotUniqueItemsList
+    uniqueItemsListInput: UniqueItemsList
+}
+
+@output
+structure UniqueItemsConstraintTestOutput {}
+
+@http(method: "POST", uri: "/nested-unique-items-constraint", code: 201)
+operation NestedUniqueItemsConstraintTest {
+    input: NestedUniqueItemsConstraintTestInput
+    output: NestedUniqueItemsConstraintTestOutput
+}
+
+@input
+structure NestedUniqueItemsConstraintTestInput {
+    nestedUniqueItemsListInput: UniqueItemsListWrap
+}
+
+@output
+structure NestedUniqueItemsConstraintTestOutput {}
+
+@http(method: "POST", uri: "/double-nested-unique-items-constraint", code: 201)
+operation DoubleNestedUniqueItemsConstraintTest {
+    input: DoubleNestedUniqueItemsConstraintTestInput
+    output: DoubleNestedUniqueItemsConstraintTestOutput
+}
+
+@input
+structure DoubleNestedUniqueItemsConstraintTestInput {
+    doubleNestedUniqueItemsListInput: UniqueItemsListWrapContainer
+}
+
+@output
+structure DoubleNestedUniqueItemsConstraintTestOutput {}
+
+list NotUniqueItemsList {
+    member: String
+}
+
+@uniqueItems
+list UniqueItemsList {
+    member: String
+}
+
+@uniqueItems
+list UniqueItemsListWrap {
+    member: UniqueItemsList
+}
+
+@uniqueItems
+list UniqueItemsListWrapContainer {
+    member: UniqueItemsListWrap
+}
+
+map MyMap {
+    key: String
+    value: String
+}
\ No newline at end of file
diff --git a/tests/codegen/service-codegen-tests/model/service-json-test.smithy b/tests/codegen/service-codegen-tests/model/service-json-test.smithy
new file mode 100644
index 0000000000..c48ef7c279
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/model/service-json-test.smithy
@@ -0,0 +1,198 @@
+$version: "2.0"
+
+namespace com.json
+
+use aws.protocols#restJson1
+
+@restJson1
+service JsonServiceTest {
+    version: "1.0.0"
+    operations: [
+        HttpHeaderTest
+        HttpLabelTest
+        HttpQueryTest
+        HttpStringPayloadTest
+        HttpStructurePayloadTest
+        TimestampTest
+        JsonNameTest
+        HttpErrorTest
+    ]
+}
+
+@http(method: "POST", uri: "/http-header", code: 201)
+operation HttpHeaderTest {
+    input: HttpHeaderTestInput
+    output: HttpHeaderTestOutput
+}
+
+@input
+structure HttpHeaderTestInput {
+    @httpHeader("X-Request-Header")
+    header: String
+
+    @httpPrefixHeaders("X-Request-Headers-")
+    headers: MapOfStrings
+}
+
+@output
+structure HttpHeaderTestOutput {
+    @httpHeader("X-Response-Header")
+    header: String
+
+    @httpPrefixHeaders("X-Response-Headers-")
+    headers: MapOfStrings
+}
+
+
+@http(method: "GET", uri: "/http-label/{foo}", code: 200)
+operation HttpLabelTest {
+    input: HttpLabelTestInput
+    output: HttpLabelTestOutput
+}
+
+@input
+structure HttpLabelTestInput {
+    @required
+    @httpLabel
+    foo: String
+}
+
+@output
+structure HttpLabelTestOutput {
+    output: String
+}
+
+@http(method: "DELETE", uri: "/http-query", code: 200)
+operation HttpQueryTest {
+    input: HttpQueryTestInput
+    output: HttpQueryTestOutput
+}
+
+@input
+structure HttpQueryTestInput {
+    @httpQuery("query")
+    query: Integer
+
+    @httpQueryParams
+    params: MapOfStrings
+}
+
+@output
+structure HttpQueryTestOutput {
+    output: String
+}
+
+
+@http(method: "POST", uri: "/http-payload/string", code: 201)
+operation HttpStringPayloadTest {
+    input: HttpStringPayloadTestInput
+    output: HttpStringPayloadTestOutput
+}
+
+@input
+structure HttpStringPayloadTestInput {
+    @httpPayload
+    content: String
+}
+
+@output
+structure HttpStringPayloadTestOutput {
+    @httpPayload
+    content: String
+}
+
+@http(method: "POST", uri: "/http-payload/structure", code: 201)
+operation HttpStructurePayloadTest {
+    input: HttpStructurePayloadTestInput
+    output: HttpStructurePayloadTestOutput
+}
+
+@input
+structure HttpStructurePayloadTestInput {
+    @httpPayload
+    content: HttpStructurePayloadTestStructure
+}
+
+@output
+structure HttpStructurePayloadTestOutput {
+    @httpPayload
+    content: HttpStructurePayloadTestStructure
+}
+
+
+@http(method: "POST", uri: "/timestamp", code: 201)
+operation TimestampTest {
+    input: TimestampTestInput
+    output: TimestampTestOutput
+}
+
+@input
+structure TimestampTestInput {
+    default: Timestamp
+    @timestampFormat("date-time")
+    dateTime: Timestamp
+    @timestampFormat("http-date")
+    httpDate: Timestamp
+    @timestampFormat("epoch-seconds")
+    epochSeconds: Timestamp
+}
+
+@output
+structure TimestampTestOutput {
+    default: Timestamp
+    @timestampFormat("date-time")
+    dateTime: Timestamp
+    @timestampFormat("http-date")
+    httpDate: Timestamp
+    @timestampFormat("epoch-seconds")
+    epochSeconds: Timestamp
+}
+
+@http(method: "POST", uri: "/json-name", code: 201)
+operation JsonNameTest {
+    input: JsonNameTestInput
+    output: JsonNameTestOutput
+}
+
+@input
+structure JsonNameTestInput {
+    @jsonName("requestName")
+    content: String
+}
+
+@output
+structure JsonNameTestOutput {
+    @jsonName("responseName")
+    content: String
+}
+
+@http(method: "POST", uri: "/http-error", code: 200)
+operation HttpErrorTest {
+    input: HttpErrorTestInput
+    output: HttpErrorTestOutput
+    errors: [HttpError]
+}
+
+@input
+structure HttpErrorTestInput {}
+
+@output
+structure HttpErrorTestOutput {}
+
+@error("client")
+@httpError(456)
+structure HttpError {
+    msg: String
+    num: Integer
+}
+
+structure HttpStructurePayloadTestStructure {
+    content1: String
+    content2: Integer
+    content3: Float
+}
+
+map MapOfStrings {
+    key: String
+    value: String
+}
\ No newline at end of file
diff --git a/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/AuthenticationServiceTestGenerator.kt b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/AuthenticationServiceTestGenerator.kt
new file mode 100644
index 0000000000..c339e08b05
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/AuthenticationServiceTestGenerator.kt
@@ -0,0 +1,119 @@
+package com.test
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.build.PluginContext
+import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
+import software.amazon.smithy.model.loader.ModelAssembler
+import software.amazon.smithy.model.node.Node
+import software.amazon.smithy.model.node.ObjectNode
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+internal fun generateAuthenticationConstraintsTest() {
+    val modelPath: Path = Paths.get("model", "service-authentication-test.smithy")
+    val defaultModel = ModelAssembler()
+        .discoverModels()
+        .addImport(modelPath)
+        .assemble()
+        .unwrap()
+    val serviceName = "AuthenticationServiceTest"
+    val packageName = "com.authentication"
+    val outputDirName = "service-authentication-test"
+
+    val packagePath = packageName.replace('.', '/')
+
+    val settings: ObjectNode = ObjectNode.builder()
+        .withMember("service", Node.from("$packageName#$serviceName"))
+        .withMember(
+            "package",
+            ObjectNode.builder()
+                .withMember("name", Node.from(packageName))
+                .withMember("version", Node.from("1.0.0"))
+                .build(),
+        )
+        .withMember(
+            "build",
+            ObjectNode.builder()
+                .withMember("rootProject", true)
+                .withMember("generateServiceProject", true)
+                .withMember(
+                    "optInAnnotations",
+                    Node.arrayNode(
+                        Node.from("aws.smithy.kotlin.runtime.InternalApi"),
+                        Node.from("kotlinx.serialization.ExperimentalSerializationApi"),
+                    ),
+                )
+                .build(),
+        )
+        .withMember(
+            "serviceStub",
+            ObjectNode.builder().withMember("framework", Node.from("ktor")).build(),
+        )
+        .build()
+    val outputDir: Path = Paths.get("build", outputDirName).also { Files.createDirectories(it) }
+    val manifest: FileManifest = FileManifest.create(outputDir)
+
+    val context: PluginContext = PluginContext.builder()
+        .model(defaultModel)
+        .fileManifest(manifest)
+        .settings(settings)
+        .build()
+    KotlinCodegenPlugin().execute(context)
+
+    val bearerValidation = """
+        package $packageName.auth
+        
+        internal object BearerValidation {
+            public fun bearerValidation(token: String): UserPrincipal? {
+                // TODO: implement me
+                if (token == "correctToken") return UserPrincipal("Authenticated User") else return null
+            }
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/auth/Validation.kt", bearerValidation)
+
+    val awsValidation = """
+        package $packageName.auth
+        
+        import aws.smithy.kotlin.runtime.auth.awscredentials.Credentials
+        
+        internal object SigV4CredentialStore {
+            private val table: Map<String, Credentials> = mapOf(
+                "AKIACORRECTEXAMPLEACCESSKEY" to Credentials(accessKeyId = "AKIACORRECTEXAMPLEACCESSKEY", secretAccessKey = "CORRECTEXAMPLESECRETKEY"),
+            )
+            internal fun get(accessKeyId: String): Credentials? {
+                return table[accessKeyId]
+            }
+        }
+        
+        internal object SigV4aPublicKeyStore {
+            private val table: MutableMap<String, java.security.PublicKey> = mutableMapOf()
+        
+            init {
+                val pem = ""${'"'}
+                    -----BEGIN PUBLIC KEY-----
+                    MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE/VTdYVFt+jAgj1N4Q+Dnpcho/XeI
+                    655JtWjFvxscKZJbDNa8F6hzo/s3lQNwMozl2p3KqmmjYwlIu9tQQkFZvQ==
+                    -----END PUBLIC KEY-----
+                ""${'"'}.trimIndent()
+                val clean = pem.replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "").replace("\\s".toRegex(), "")
+                val keyBytes = java.util.Base64.getDecoder().decode(clean)
+                val spec = java.security.spec.X509EncodedKeySpec(keyBytes)
+                val kf = java.security.KeyFactory.getInstance("EC")
+                table["AKIACORRECTEXAMPLEACCESSKEY"] = kf.generatePublic(spec)
+            }
+        
+            internal fun get(accessKeyId: String): java.security.PublicKey? {
+                return table[accessKeyId]
+            }
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/auth/AWSValidation.kt", awsValidation)
+
+    val settingGradleKts = """
+        rootProject.name = "service-authentication-test"
+        includeBuild("../../../../../")
+    """.trimIndent()
+    manifest.writeFile("settings.gradle.kts", settingGradleKts)
+}
diff --git a/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/CborServiceTestGenerator.kt b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/CborServiceTestGenerator.kt
new file mode 100644
index 0000000000..b9e69a8642
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/CborServiceTestGenerator.kt
@@ -0,0 +1,119 @@
+package com.test
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.build.PluginContext
+import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
+import software.amazon.smithy.model.loader.ModelAssembler
+import software.amazon.smithy.model.node.Node
+import software.amazon.smithy.model.node.ObjectNode
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+internal fun generateCborServiceTest() {
+    val modelPath: Path = Paths.get("model", "service-cbor-test.smithy")
+    val defaultModel = ModelAssembler()
+        .discoverModels()
+        .addImport(modelPath)
+        .assemble()
+        .unwrap()
+    val serviceName = "CborServiceTest"
+    val packageName = "com.cbor"
+    val outputDirName = "service-cbor-test"
+
+    val packagePath = packageName.replace('.', '/')
+
+    val settings: ObjectNode = ObjectNode.builder()
+        .withMember("service", Node.from("$packageName#$serviceName"))
+        .withMember(
+            "package",
+            ObjectNode.builder()
+                .withMember("name", Node.from(packageName))
+                .withMember("version", Node.from("1.0.0"))
+                .build(),
+        )
+        .withMember(
+            "build",
+            ObjectNode.builder()
+                .withMember("rootProject", true)
+                .withMember("generateServiceProject", true)
+                .withMember(
+                    "optInAnnotations",
+                    Node.arrayNode(
+                        Node.from("aws.smithy.kotlin.runtime.InternalApi"),
+                        Node.from("kotlinx.serialization.ExperimentalSerializationApi"),
+                    ),
+                )
+                .build(),
+        )
+        .withMember(
+            "serviceStub",
+            ObjectNode.builder().withMember("framework", Node.from("ktor")).build(),
+        )
+        .build()
+    val outputDir: Path = Paths.get("build", outputDirName).also { Files.createDirectories(it) }
+    val manifest: FileManifest = FileManifest.create(outputDir)
+
+    val context: PluginContext = PluginContext.builder()
+        .model(defaultModel)
+        .fileManifest(manifest)
+        .settings(settings)
+        .build()
+    KotlinCodegenPlugin().execute(context)
+
+    val postTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.PostTestRequest
+        import $packageName.model.PostTestResponse
+
+        public fun handlePostTestRequest(req: PostTestRequest): PostTestResponse {
+            val response = PostTestResponse.Builder()
+            val input1 = req.input1 ?: ""
+            val input2 = req.input2 ?: 0
+            response.output1 = input1 + " world!"
+            response.output2 = input2 + 1
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/PostTestOperation.kt", postTestOperation)
+
+    val errorTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.ErrorTestRequest
+        import $packageName.model.ErrorTestResponse
+
+        public fun handleErrorTestRequest(req: ErrorTestRequest): ErrorTestResponse {
+            val variable: String? = null
+            val error = variable!!.length
+            return ErrorTestResponse.Builder().build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/ErrorTestOperation.kt", errorTestOperation)
+
+    val httpErrorTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpErrorTestRequest
+        import $packageName.model.HttpErrorTestResponse
+        import $packageName.model.HttpError
+
+        public fun handleHttpErrorTestRequest(req: HttpErrorTestRequest): HttpErrorTestResponse {
+            
+            val error = HttpError.Builder()
+            error.msg = "this is an error message"
+            error.num = 444
+            throw error.build()
+            
+            return HttpErrorTestResponse.Builder().build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpErrorTestOperation.kt", httpErrorTestOperation)
+
+    val settingGradleKts = """
+        rootProject.name = "service-cbor-test"
+        includeBuild("../../../../../")
+    """.trimIndent()
+    manifest.writeFile("settings.gradle.kts", settingGradleKts)
+}
diff --git a/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/ConstraintsServiceTestGenerator.kt b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/ConstraintsServiceTestGenerator.kt
new file mode 100644
index 0000000000..adcf520f61
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/ConstraintsServiceTestGenerator.kt
@@ -0,0 +1,69 @@
+package com.test
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.build.PluginContext
+import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
+import software.amazon.smithy.model.loader.ModelAssembler
+import software.amazon.smithy.model.node.Node
+import software.amazon.smithy.model.node.ObjectNode
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+internal fun generateServiceConstraintsTest() {
+    val modelPath: Path = Paths.get("model", "service-constraints-test.smithy")
+    val defaultModel = ModelAssembler()
+        .discoverModels()
+        .addImport(modelPath)
+        .assemble()
+        .unwrap()
+    val serviceName = "ServiceConstraintsTest"
+    val packageName = "com.constraints"
+    val outputDirName = "service-constraints-test"
+
+    val packagePath = packageName.replace('.', '/')
+
+    val settings: ObjectNode = ObjectNode.builder()
+        .withMember("service", Node.from("$packageName#$serviceName"))
+        .withMember(
+            "package",
+            ObjectNode.builder()
+                .withMember("name", Node.from(packageName))
+                .withMember("version", Node.from("1.0.0"))
+                .build(),
+        )
+        .withMember(
+            "build",
+            ObjectNode.builder()
+                .withMember("rootProject", true)
+                .withMember("generateServiceProject", true)
+                .withMember(
+                    "optInAnnotations",
+                    Node.arrayNode(
+                        Node.from("aws.smithy.kotlin.runtime.InternalApi"),
+                        Node.from("kotlinx.serialization.ExperimentalSerializationApi"),
+                    ),
+                )
+                .build(),
+        )
+        .withMember(
+            "serviceStub",
+            ObjectNode.builder().withMember("framework", Node.from("ktor")).build(),
+        )
+        .build()
+    val outputDir: Path = Paths.get("build", outputDirName).also { Files.createDirectories(it) }
+    val manifest: FileManifest = FileManifest.create(outputDir)
+
+    val context: PluginContext = PluginContext.builder()
+        .model(defaultModel)
+        .fileManifest(manifest)
+        .settings(settings)
+        .build()
+    KotlinCodegenPlugin().execute(context)
+
+    val settingGradleKts = """
+        rootProject.name = "service-constraints-test"
+        includeBuild("../../../../../")
+    """.trimIndent()
+    manifest.writeFile("settings.gradle.kts", settingGradleKts)
+}
diff --git a/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/DefaultServiceGeneratorTest.kt b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/DefaultServiceGeneratorTest.kt
new file mode 100644
index 0000000000..3a816637ed
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/DefaultServiceGeneratorTest.kt
@@ -0,0 +1,8 @@
+package com.test
+
+internal fun main() {
+    generateCborServiceTest()
+    generateJsonServiceTest()
+    generateServiceConstraintsTest()
+    generateAuthenticationConstraintsTest()
+}
diff --git a/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/JsonServiceTestGenerator.kt b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/JsonServiceTestGenerator.kt
new file mode 100644
index 0000000000..b21e4e1a6b
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/main/kotlin/com/test/JsonServiceTestGenerator.kt
@@ -0,0 +1,195 @@
+package com.test
+
+import software.amazon.smithy.build.FileManifest
+import software.amazon.smithy.build.PluginContext
+import software.amazon.smithy.kotlin.codegen.KotlinCodegenPlugin
+import software.amazon.smithy.model.loader.ModelAssembler
+import software.amazon.smithy.model.node.Node
+import software.amazon.smithy.model.node.ObjectNode
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+internal fun generateJsonServiceTest() {
+    val modelPath: Path = Paths.get("model", "service-json-test.smithy")
+    val defaultModel = ModelAssembler()
+        .discoverModels()
+        .addImport(modelPath)
+        .assemble()
+        .unwrap()
+    val serviceName = "JsonServiceTest"
+    val packageName = "com.json"
+    val outputDirName = "service-json-test"
+
+    val packagePath = packageName.replace('.', '/')
+
+    val settings: ObjectNode = ObjectNode.builder()
+        .withMember("service", Node.from("$packageName#$serviceName"))
+        .withMember(
+            "package",
+            ObjectNode.builder()
+                .withMember("name", Node.from(packageName))
+                .withMember("version", Node.from("1.0.0"))
+                .build(),
+        )
+        .withMember(
+            "build",
+            ObjectNode.builder()
+                .withMember("rootProject", true)
+                .withMember("generateServiceProject", true)
+                .withMember(
+                    "optInAnnotations",
+                    Node.arrayNode(
+                        Node.from("aws.smithy.kotlin.runtime.InternalApi"),
+                        Node.from("kotlinx.serialization.ExperimentalSerializationApi"),
+                    ),
+                )
+                .build(),
+        )
+        .withMember(
+            "serviceStub",
+            ObjectNode.builder().withMember("framework", Node.from("ktor")).build(),
+        )
+        .build()
+    val outputDir: Path = Paths.get("build", outputDirName).also { Files.createDirectories(it) }
+    val manifest: FileManifest = FileManifest.create(outputDir)
+
+    val context: PluginContext = PluginContext.builder()
+        .model(defaultModel)
+        .fileManifest(manifest)
+        .settings(settings)
+        .build()
+    KotlinCodegenPlugin().execute(context)
+
+    val httpHeaderTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpHeaderTestRequest
+        import $packageName.model.HttpHeaderTestResponse
+
+        public fun handleHttpHeaderTestRequest(req: HttpHeaderTestRequest): HttpHeaderTestResponse {
+            val response = HttpHeaderTestResponse.Builder()
+            response.header = req.headers?.get("hhh")
+            response.headers = mapOf("hhh" to (req.header ?: ""))
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpHeaderTestOperation.kt", httpHeaderTestOperation)
+
+    val httpLabelTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpLabelTestRequest
+        import $packageName.model.HttpLabelTestResponse
+
+        public fun handleHttpLabelTestRequest(req: HttpLabelTestRequest): HttpLabelTestResponse {
+            val response = HttpLabelTestResponse.Builder()
+            response.output = req.foo
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpLabelTestOperation.kt", httpLabelTestOperation)
+
+    val httpQueryTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpQueryTestRequest
+        import $packageName.model.HttpQueryTestResponse
+
+        public fun handleHttpQueryTestRequest(req: HttpQueryTestRequest): HttpQueryTestResponse {
+            val response = HttpQueryTestResponse.Builder()
+            response.output = req.query.toString() + (req.params?.get("qqq") ?: "")
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpQueryTestOperation.kt", httpQueryTestOperation)
+
+    val httpStringPayloadTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpStringPayloadTestRequest
+        import $packageName.model.HttpStringPayloadTestResponse
+
+        public fun handleHttpStringPayloadTestRequest(req: HttpStringPayloadTestRequest): HttpStringPayloadTestResponse {
+            val response = HttpStringPayloadTestResponse.Builder()
+            response.content = req.content
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpStringPayloadTestOperation.kt", httpStringPayloadTestOperation)
+
+    val httpStructurePayloadTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpStructurePayloadTestRequest
+        import $packageName.model.HttpStructurePayloadTestResponse
+        import $packageName.model.HttpStructurePayloadTestStructure
+
+        public fun handleHttpStructurePayloadTestRequest(req: HttpStructurePayloadTestRequest): HttpStructurePayloadTestResponse {
+            val response = HttpStructurePayloadTestResponse.Builder()
+            val content = HttpStructurePayloadTestStructure.Builder()
+            content.content1 = req.content?.content1
+            content.content2 = req.content?.content2
+            content.content3 = req.content?.content3
+            response.content = content.build()
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpStructurePayloadTestOperation.kt", httpStructurePayloadTestOperation)
+
+    val timestampTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.TimestampTestRequest
+        import $packageName.model.TimestampTestResponse
+
+        public fun handleTimestampTestRequest(req: TimestampTestRequest): TimestampTestResponse {
+            val response = TimestampTestResponse.Builder()
+            response.default = req.default
+            response.dateTime = req.dateTime
+            response.httpDate = req.httpDate
+            response.epochSeconds = req.epochSeconds
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/TimestampTestOperation.kt", timestampTestOperation)
+
+    val jsonNameTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.JsonNameTestRequest
+        import $packageName.model.JsonNameTestResponse
+
+        public fun handleJsonNameTestRequest(req: JsonNameTestRequest): JsonNameTestResponse {
+            val response = JsonNameTestResponse.Builder()
+            response.content = req.content
+            return response.build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/JsonNameTestOperation.kt", jsonNameTestOperation)
+
+    val httpErrorTestOperation = """
+        package $packageName.operations
+
+        import $packageName.model.HttpErrorTestRequest
+        import $packageName.model.HttpErrorTestResponse
+        import $packageName.model.HttpError
+
+        public fun handleHttpErrorTestRequest(req: HttpErrorTestRequest): HttpErrorTestResponse {
+            
+            val error = HttpError.Builder()
+            error.msg = "this is an error message"
+            error.num = 444
+            throw error.build()
+            
+            return HttpErrorTestResponse.Builder().build()
+        }
+    """.trimIndent()
+    manifest.writeFile("src/main/kotlin/$packagePath/operations/HttpErrorTestOperation.kt", httpErrorTestOperation)
+
+    val settingGradleKts = """
+        rootProject.name = "service-json-test"
+        includeBuild("../../../../../")
+    """.trimIndent()
+    manifest.writeFile("settings.gradle.kts", settingGradleKts)
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/AuthenticationServiceTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/AuthenticationServiceTest.kt
new file mode 100644
index 0000000000..0bfb55872b
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/AuthenticationServiceTest.kt
@@ -0,0 +1,656 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import aws.smithy.kotlin.runtime.auth.awscredentials.Credentials
+import aws.smithy.kotlin.runtime.auth.awssigning.AwsSigningAlgorithm
+import kotlinx.serialization.json.Json
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import java.net.ServerSocket
+import java.net.http.HttpResponse
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class AuthenticationServiceTest {
+    val closeGracePeriodMillis = TestParams.CLOSE_GRACE_PERIOD_MILLIS
+    val closeTimeoutMillis = TestParams.CLOSE_TIMEOUT_MILLIS
+    val gracefulWindow = TestParams.GRACEFUL_WINDOW
+    val requestBodyLimit = TestParams.REQUEST_BODY_LIMIT
+    val portListenerTimeout = TestParams.PORT_LISTENER_TIMEOUT
+
+    val port: Int = ServerSocket(0).use { it.localPort }
+    val baseUrl = "http://localhost:$port"
+
+    val projectDir: Path = Paths.get("build/service-authentication-test")
+
+    private lateinit var proc: Process
+
+    @BeforeAll
+    fun boot() {
+        proc = startService("netty", port, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(port, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+    }
+
+    @AfterAll
+    fun shutdown() = cleanupService(proc, gracefulWindow)
+
+    @Test
+    fun `checks bearer authentication with correct token`() {
+        val response = sendRequest(
+            "$baseUrl/only-bearer",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            "correctToken",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks bearer authentication with wrong token`() {
+        val response = sendRequest(
+            "$baseUrl/only-bearer",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            "wrongToken",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks bearer authentication without token`() {
+        val response = sendRequest(
+            "$baseUrl/only-bearer",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Missing bearer token", body.message)
+    }
+
+    @Test
+    fun `checks sigv4 authentication with correct signature`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/only-sigv4",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4 authentication with wrong region`() {
+        val region = "us-east-2"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/only-sigv4",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4 authentication with wrong service name`() {
+        val region = "us-east-1"
+        val service = "service-2"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/only-sigv4",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4 authentication with wrong access key`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIAWRONGEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/only-sigv4",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4 authentication with wrong secret key`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "WRONGEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/only-sigv4",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4a authentication with correct signature`() {
+        val region = "*"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4a authentication with specific region`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4a authentication with multi regions`() {
+        val region = "us-east-*"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4a authentication with wrong region`() {
+        val region = "us-east-2"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4a authentication with wrong access key`() {
+        val region = "*"
+        val service = "service-1"
+
+        val accessKey = "AKIAWRONGEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks sigv4a authentication with wrong secret key`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "WRONGEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(401, response.statusCode(), "Expected 401")
+
+        val body = Json.decodeFromString(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(401, body.code)
+        assertEquals("Invalid or expired authentication", body.message)
+    }
+
+    @Test
+    fun `checks multi authentications with bearer token`() {
+        val response = sendRequest(
+            "$baseUrl/all-authentication",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            "correctToken",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks multi authentications with sigv4 token`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/all-authentication",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks multi authentications with sigv4a token`() {
+        val region = "*"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val response = sendRequest(
+            "$baseUrl/all-authentication",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks no authentication`() {
+        val response = sendRequest(
+            "$baseUrl/no-authentication",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            null,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4 authentication with body with correct signature`() {
+        val region = "us-east-1"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4,
+        )
+
+        val requestJson = Json.encodeToJsonElement(
+            AuthTestRequest.serializer(),
+            AuthTestRequest("this is a test input"),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4-authentication-body",
+            "POST",
+            requestJson,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks sigv4a authentication with body with correct signature`() {
+        val region = "*"
+        val service = "service-1"
+
+        val accessKey = "AKIACORRECTEXAMPLEACCESSKEY"
+        val secretKey = "CORRECTEXAMPLESECRETKEY"
+
+        val creds = Credentials(accessKey, secretKey)
+
+        val signingOptions = AwsSigningOptions(
+            credentials = creds,
+            service = service,
+            region = region,
+            algorithm = AwsSigningAlgorithm.SIGV4_ASYMMETRIC,
+        )
+
+        val requestJson = Json.encodeToJsonElement(
+            AuthTestRequest.serializer(),
+            AuthTestRequest("this is a test input"),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/sigv4a-authentication-body",
+            "POST",
+            requestJson,
+            "application/json",
+            "application/json",
+            null,
+            mapOf(),
+            signingOptions,
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/CborServiceTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/CborServiceTest.kt
new file mode 100644
index 0000000000..600a68d72f
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/CborServiceTest.kt
@@ -0,0 +1,329 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import kotlinx.serialization.cbor.Cbor
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import java.net.ServerSocket
+import java.net.http.HttpResponse
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class CborServiceTest {
+    val closeGracePeriodMillis = TestParams.CLOSE_GRACE_PERIOD_MILLIS
+    val closeTimeoutMillis = TestParams.CLOSE_TIMEOUT_MILLIS
+    val gracefulWindow = TestParams.GRACEFUL_WINDOW
+    val requestBodyLimit = TestParams.REQUEST_BODY_LIMIT
+    val portListenerTimeout = TestParams.PORT_LISTENER_TIMEOUT
+
+    val port: Int = ServerSocket(0).use { it.localPort }
+    val baseUrl = "http://localhost:$port"
+
+    val projectDir: Path = Paths.get("build/service-cbor-test")
+
+    private lateinit var proc: Process
+
+    @BeforeAll
+    fun boot() {
+        proc = startService("netty", port, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(port, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+    }
+
+    @AfterAll
+    fun shutdown() = cleanupService(proc, gracefulWindow)
+
+    @Test
+    fun `checks correct POST request`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+
+        val body = cbor.decodeFromByteArray(
+            PostTestResponse.serializer(),
+            response.body(),
+        )
+
+        assertEquals("Hello world!", body.output1)
+        assertEquals(input2 + 1, body.output2)
+    }
+
+    @Test
+    fun `checks unhandled runtime exception in handler`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val requestBytes = cbor.encodeToByteArray(
+            ErrorTestRequest.serializer(),
+            ErrorTestRequest(input1),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/error",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(500, response.statusCode(), "Expected 500")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(500, body.code)
+        assertEquals("Unexpected error", body.message)
+    }
+
+    @Test
+    fun `checks wrong content type`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/json",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(415, response.statusCode(), "Expected 415")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(415, body.code)
+        assertEquals("Not acceptable Content‑Type found: 'application/json'. Accepted content types: application/cbor", body.message)
+    }
+
+    @Test
+    fun `checks missing content type`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            acceptType = "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(415, response.statusCode(), "Expected 415")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(415, body.code)
+        assertEquals("Not acceptable Content‑Type found: '*/*'. Accepted content types: application/cbor", body.message)
+    }
+
+    @Test
+    fun `checks wrong accept type`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(406, response.statusCode(), "Expected 406")
+
+        assertEquals("""{"code":406,"message":"Not acceptable Accept type found: '[application/json]'. Accepted types: application/cbor"}""", response.body())
+    }
+
+    @Test
+    fun `checks missing accept type`() {
+        val cbor = Cbor { }
+        val input1 = "Hello"
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks malformed input`() {
+        val cbor = Cbor { }
+        val input1 = 123
+        val input2 = "Hello"
+        val requestBytes = cbor.encodeToByteArray(
+            MalformedPostTestRequest.serializer(),
+            MalformedPostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("Unexpected EOF: expected 109 more bytes; consumed: 14", body.message)
+    }
+
+    @Test
+    fun `checks route not found`() {
+        val cbor = Cbor { }
+        val requestBytes = ByteArray(0)
+        val response = sendRequest(
+            "$baseUrl/does-not-exist",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(404, response.statusCode(), "Expected 404")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(404, body.code)
+        assertEquals("Resource not found", body.message)
+    }
+
+    @Test
+    fun `checks method not allowed`() {
+        val cbor = Cbor { }
+        val input1 = 123
+        val input2 = "Hello"
+        val requestBytes = cbor.encodeToByteArray(
+            MalformedPostTestRequest.serializer(),
+            MalformedPostTestRequest(input1, input2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "PUT",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(405, response.statusCode(), "Expected 405")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(405, body.code)
+        assertEquals("Method not allowed for this resource", body.message)
+    }
+
+    @Test
+    fun `checks request body limit`() {
+        val cbor = Cbor { }
+        val overLimitPayload = "x".repeat(requestBodyLimit.toInt() + 1)
+        val input2 = 617
+        val requestBytes = cbor.encodeToByteArray(
+            PostTestRequest.serializer(),
+            PostTestRequest(overLimitPayload, input2),
+        )
+        require(requestBytes.size > 10 * 1024 * 1024)
+
+        val response = sendRequest(
+            "$baseUrl/post",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(413, response.statusCode(), "Expected 413")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(413, body.code)
+        assertEquals("Request is larger than the limit of 10485760 bytes", body.message)
+    }
+
+    @Test
+    fun `checks http error`() {
+        val cbor = Cbor { }
+
+        val response = sendRequest(
+            "$baseUrl/http-error",
+            "POST",
+            null,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+
+        assertEquals(456, response.statusCode(), "Expected 456")
+        val body = cbor.decodeFromByteArray(
+            HttpError.serializer(),
+            response.body(),
+        )
+
+        assertEquals(444, body.num)
+        assertEquals("this is an error message", body.msg)
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/JsonServiceTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/JsonServiceTest.kt
new file mode 100644
index 0000000000..2df32dfc30
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/JsonServiceTest.kt
@@ -0,0 +1,221 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import kotlinx.serialization.builtins.serializer
+import kotlinx.serialization.json.Json
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import java.net.ServerSocket
+import java.net.http.HttpResponse
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class JsonServiceTest {
+    val closeGracePeriodMillis = TestParams.CLOSE_GRACE_PERIOD_MILLIS
+    val closeTimeoutMillis = TestParams.CLOSE_TIMEOUT_MILLIS
+    val gracefulWindow = TestParams.GRACEFUL_WINDOW
+    val requestBodyLimit = TestParams.REQUEST_BODY_LIMIT
+    val portListenerTimeout = TestParams.PORT_LISTENER_TIMEOUT
+
+    val port: Int = ServerSocket(0).use { it.localPort }
+    val baseUrl = "http://localhost:$port"
+
+    val projectDir: Path = Paths.get("build/service-json-test")
+
+    private lateinit var proc: Process
+
+    @BeforeAll
+    fun boot() {
+        proc = startService("netty", port, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(port, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+    }
+
+    @AfterAll
+    fun shutdown() = cleanupService(proc, gracefulWindow)
+
+    @Test
+    fun `checks http-header`() {
+        val response = sendRequest(
+            "$baseUrl/http-header",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+            headers = mapOf("X-Request-Header" to "header", "X-Request-Headers-hhh" to "headers"),
+        )
+        assertIs<HttpResponse<String>>(response)
+
+        assertEquals(201, response.statusCode(), "Expected 201")
+
+        assertEquals("headers", response.headers().firstValue("X-Response-Header").get())
+        assertEquals("header", response.headers().firstValue("X-Response-Headers-hhh").get())
+    }
+
+    @Test
+    fun `checks http-label`() {
+        val response = sendRequest(
+            "$baseUrl/http-label/labelValue",
+            "GET",
+            null,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+
+        assertEquals(200, response.statusCode(), "Expected 200")
+        val body = Json.decodeFromString(
+            HttpLabelTestOutputResponse.serializer(),
+            response.body(),
+        )
+        assertEquals("labelValue", body.output)
+    }
+
+    @Test
+    fun `checks http-query`() {
+        val response = sendRequest(
+            "$baseUrl/http-query?query=123&qqq=kotlin",
+            "DELETE",
+            null,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+
+        assertEquals(200, response.statusCode(), "Expected 200")
+        val body = Json.decodeFromString(
+            HttpQueryTestOutputResponse.serializer(),
+            response.body(),
+        )
+        assertEquals("123kotlin", body.output)
+    }
+
+    @Test
+    fun `checks http-payload string`() {
+        val response = sendRequest(
+            "$baseUrl/http-payload/string",
+            "POST",
+            "This is the entire content",
+            "text/plain",
+            "text/plain",
+        )
+        assertIs<HttpResponse<String>>(response)
+
+        assertEquals(201, response.statusCode(), "Expected 201")
+        assertEquals("This is the entire content", response.body())
+    }
+
+    @Test
+    fun `checks http-payload structure`() {
+        val requestJson = Json.encodeToJsonElement(
+            HttpStructurePayloadTestStructure.serializer(),
+            HttpStructurePayloadTestStructure(
+                "content",
+                123,
+                456.toFloat(),
+            ),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/http-payload/structure",
+            "POST",
+            requestJson,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+        val body = Json.decodeFromString(
+            HttpStructurePayloadTestStructure.serializer(),
+            response.body(),
+        )
+        assertEquals("content", body.content1)
+        assertEquals(123, body.content2)
+        assertEquals(456.toFloat(), body.content3)
+    }
+
+    @Test
+    fun `checks timestamp`() {
+        val requestJson = Json.encodeToJsonElement(
+            TimestampTestRequestResponse.serializer(),
+            TimestampTestRequestResponse(
+                1515531081.123,
+                "1985-04-12T23:20:50.520Z",
+                "Tue, 29 Apr 2014 18:30:38 GMT",
+                1234567890.123,
+            ),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/timestamp",
+            "POST",
+            requestJson,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+        val body = Json.decodeFromString(
+            TimestampTestRequestResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(1515531081.123, body.default)
+        assertEquals("1985-04-12T23:20:50.520Z", body.dateTime)
+        assertEquals("Tue, 29 Apr 2014 18:30:38 GMT", body.httpDate)
+        assertEquals(1234567890.123, body.epochSeconds)
+    }
+
+    @Test
+    fun `checks json name`() {
+        val requestJson = Json.encodeToJsonElement(
+            JsonNameTestRequest.serializer(),
+            JsonNameTestRequest("Hello Kotlin Team"),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/json-name",
+            "POST",
+            requestJson,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+        val body = Json.decodeFromString(
+            JsonNameTestResponse.serializer(),
+            response.body(),
+        )
+        assertEquals("Hello Kotlin Team", body.responseName)
+    }
+
+    @Test
+    fun `checks http error`() {
+        val response = sendRequest(
+            "$baseUrl/http-error",
+            "POST",
+            null,
+            "application/json",
+            "application/json",
+        )
+        assertIs<HttpResponse<String>>(response)
+
+        assertEquals(456, response.statusCode(), "Expected 456")
+        val body = Json.decodeFromString(
+            HttpError.serializer(),
+            response.body(),
+        )
+
+        assertEquals(444, body.num)
+        assertEquals("this is an error message", body.msg)
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceConstraintsTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceConstraintsTest.kt
new file mode 100644
index 0000000000..0f5c9cff1c
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceConstraintsTest.kt
@@ -0,0 +1,552 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import kotlinx.serialization.cbor.Cbor
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import java.net.ServerSocket
+import java.net.http.HttpResponse
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertIs
+import kotlin.test.assertTrue
+
+/* Tests for checking constraint traits work */
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class ServiceConstraintsTest {
+    val closeGracePeriodMillis = TestParams.CLOSE_GRACE_PERIOD_MILLIS
+    val closeTimeoutMillis = TestParams.CLOSE_TIMEOUT_MILLIS
+    val gracefulWindow = TestParams.GRACEFUL_WINDOW
+    val requestBodyLimit = TestParams.REQUEST_BODY_LIMIT
+    val portListenerTimeout = TestParams.PORT_LISTENER_TIMEOUT
+
+    val port: Int = ServerSocket(0).use { it.localPort }
+    val baseUrl = "http://localhost:$port"
+
+    val projectDir: Path = Paths.get("build/service-constraints-test")
+
+    private lateinit var proc: Process
+
+    @BeforeAll
+    fun boot() {
+        proc = startService("netty", port, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(port, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+    }
+
+    @AfterAll
+    fun shutdown() = cleanupService(proc, gracefulWindow)
+
+    @Test
+    fun `checks required constraint providing all data`() {
+        val cbor = Cbor { }
+        val requiredInput = "Hello"
+        val notRequiredInput = "World"
+        val requestBytes = cbor.encodeToByteArray(
+            RequiredConstraintTestRequest.serializer(),
+            RequiredConstraintTestRequest(requiredInput, notRequiredInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/required-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks required constraint without providing non-required data`() {
+        val cbor = Cbor { }
+        val requiredInput = "Hello"
+        val requestBytes = cbor.encodeToByteArray(
+            RequiredConstraintTestRequest.serializer(),
+            RequiredConstraintTestRequest(requiredInput, null),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/required-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks required constraint without providing required data`() {
+        val cbor = Cbor { }
+        val nonRequiredInput = "World"
+        val requestBytes = cbor.encodeToByteArray(
+            RequiredConstraintTestRequest.serializer(),
+            RequiredConstraintTestRequest(null, nonRequiredInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/required-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`requiredInput` must be provided", body.message)
+    }
+
+    @Test
+    fun `checks length constraint providing correct data`() {
+        val cbor = Cbor { }
+        val greaterLengthInput = "1234567890"
+        val smallerLengthInput = listOf("1", "2", "3")
+        val betweenLengthInput = mapOf("1" to "2", "3" to "4")
+
+        val requestBytes = cbor.encodeToByteArray(
+            LengthConstraintTestRequest.serializer(),
+            LengthConstraintTestRequest(greaterLengthInput, smallerLengthInput, betweenLengthInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/length-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks length constraint violating greater than or equal to`() {
+        val cbor = Cbor { }
+        val greaterLengthInput = "1"
+        val smallerLengthInput = listOf("1", "2", "3")
+        val betweenLengthInput = mapOf("1" to "2", "3" to "4")
+
+        val requestBytes = cbor.encodeToByteArray(
+            LengthConstraintTestRequest.serializer(),
+            LengthConstraintTestRequest(greaterLengthInput, smallerLengthInput, betweenLengthInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/length-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("The size of `greaterLengthInput` must be greater than or equal to 3", body.message)
+    }
+
+    @Test
+    fun `checks length constraint violating smaller than or equal to`() {
+        val cbor = Cbor { }
+        val greaterLengthInput = "123456789"
+        val smallerLengthInput = listOf("1", "2", "3", "4", "5", "6")
+        val betweenLengthInput = mapOf("1" to "2", "3" to "4")
+
+        val requestBytes = cbor.encodeToByteArray(
+            LengthConstraintTestRequest.serializer(),
+            LengthConstraintTestRequest(greaterLengthInput, smallerLengthInput, betweenLengthInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/length-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("The size of `smallerLengthInput` must be less than or equal to 3", body.message)
+    }
+
+    @Test
+    fun `checks length constraint violating between`() {
+        val cbor = Cbor { }
+        val greaterLengthInput = "123456789"
+        val smallerLengthInput = listOf("1", "2")
+        val betweenLengthInput = mapOf("1" to "2", "3" to "4", "5" to "6", "7" to "8")
+
+        val requestBytes = cbor.encodeToByteArray(
+            LengthConstraintTestRequest.serializer(),
+            LengthConstraintTestRequest(greaterLengthInput, smallerLengthInput, betweenLengthInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/length-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("The size of `betweenLengthInput` must be between 1 and 2 (inclusive)", body.message)
+    }
+
+    @Test
+    fun `checks pattern constraint providing correct data`() {
+        val cbor = Cbor { }
+        val patternInput1 = "qwertyuiop"
+        val patternInput2 = "qwe123rty"
+
+        val requestBytes = cbor.encodeToByteArray(
+            PatternConstraintTestRequest.serializer(),
+            PatternConstraintTestRequest(patternInput1, patternInput2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/pattern-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks pattern constraint providing incorrect pattern 1`() {
+        val cbor = Cbor { }
+        val patternInput1 = "qwertyuiop1"
+        val patternInput2 = "qwe123rty"
+
+        val requestBytes = cbor.encodeToByteArray(
+            PatternConstraintTestRequest.serializer(),
+            PatternConstraintTestRequest(patternInput1, patternInput2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/pattern-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("Value `qwertyuiop1` does not match required pattern: `^[A-Za-z]+\$`", body.message)
+    }
+
+    @Test
+    fun `checks pattern constraint providing incorrect pattern 2`() {
+        val cbor = Cbor { }
+        val patternInput1 = "qwertyuiop"
+        val patternInput2 = "qwerty"
+
+        val requestBytes = cbor.encodeToByteArray(
+            PatternConstraintTestRequest.serializer(),
+            PatternConstraintTestRequest(patternInput1, patternInput2),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/pattern-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("Value `qwerty` does not match required pattern: `[1-9]+`", body.message)
+    }
+
+    @Test
+    fun `checks range constraint providing correct data`() {
+        val cbor = Cbor { }
+        val betweenInput = 3
+        val greaterInput = (-1).toDouble()
+        val smallerInput = 8.toFloat()
+
+        val requestBytes = cbor.encodeToByteArray(
+            RangeConstraintTestRequest.serializer(),
+            RangeConstraintTestRequest(betweenInput, greaterInput, smallerInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/range-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks range constraint violating greater than or equal to`() {
+        val cbor = Cbor { }
+        val betweenInput = 3
+        val greaterInput = (-100).toDouble()
+        val smallerInput = 8.toFloat()
+
+        val requestBytes = cbor.encodeToByteArray(
+            RangeConstraintTestRequest.serializer(),
+            RangeConstraintTestRequest(betweenInput, greaterInput, smallerInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/range-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`greaterInput` must be greater than or equal to -10", body.message)
+    }
+
+    @Test
+    fun `checks range constraint violating smaller than or equal to`() {
+        val cbor = Cbor { }
+        val betweenInput = 3
+        val greaterInput = (-1).toDouble()
+        val smallerInput = 10.toFloat()
+
+        val requestBytes = cbor.encodeToByteArray(
+            RangeConstraintTestRequest.serializer(),
+            RangeConstraintTestRequest(betweenInput, greaterInput, smallerInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/range-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`smallerInput` must be less than or equal to 9", body.message)
+    }
+
+    @Test
+    fun `checks range constraint violating between`() {
+        val cbor = Cbor { }
+        val betweenInput = -1
+        val greaterInput = (-1).toDouble()
+        val smallerInput = 8.toFloat()
+
+        val requestBytes = cbor.encodeToByteArray(
+            RangeConstraintTestRequest.serializer(),
+            RangeConstraintTestRequest(betweenInput, greaterInput, smallerInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/range-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`betweenInput` must be between 0 and 5 (inclusive)", body.message)
+    }
+
+    @Test
+    fun `checks unique items constraint providing correct data`() {
+        val cbor = Cbor { }
+        val notUniqueInput = listOf("1", "2", "3", "4", "5", "1", "2", "3", "3", "4", "5")
+        val uniqueInput = listOf("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11")
+
+        val requestBytes = cbor.encodeToByteArray(
+            UniqueItemsConstraintTestRequest.serializer(),
+            UniqueItemsConstraintTestRequest(notUniqueInput, uniqueInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/unique-items-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks unique items constraint providing non unique list`() {
+        val cbor = Cbor { }
+        val notUniqueInput = listOf("1", "2", "3", "4", "5", "1", "2", "3", "3", "4", "5")
+        val uniqueInput = listOf("1", "2", "3", "4", "5", "1", "2", "3", "3", "4", "5")
+
+        val requestBytes = cbor.encodeToByteArray(
+            UniqueItemsConstraintTestRequest.serializer(),
+            UniqueItemsConstraintTestRequest(notUniqueInput, uniqueInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/unique-items-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`uniqueItemsListInput` must contain only unique items, duplicate values are not allowed", body.message)
+    }
+
+    @Test
+    fun `checks unique items constraint providing unique nested list`() {
+        val cbor = Cbor { }
+        val nestedUniqueItemsListInput = listOf(listOf("1"), listOf("2", "3"), listOf("4"), listOf("5", "6", "7"))
+
+        val requestBytes = cbor.encodeToByteArray(
+            NestedUniqueItemsConstraintTestRequest.serializer(),
+            NestedUniqueItemsConstraintTestRequest(nestedUniqueItemsListInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/nested-unique-items-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(201, response.statusCode(), "Expected 201")
+    }
+
+    @Test
+    fun `checks unique items constraint providing non-unique nested list`() {
+        val cbor = Cbor { }
+        val nestedUniqueItemsListInput = listOf(listOf("1"), listOf("2", "2"), listOf("4"), listOf("5", "6", "7"))
+
+        val requestBytes = cbor.encodeToByteArray(
+            NestedUniqueItemsConstraintTestRequest.serializer(),
+            NestedUniqueItemsConstraintTestRequest(nestedUniqueItemsListInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/nested-unique-items-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`member` must contain only unique items, duplicate values are not allowed", body.message)
+    }
+
+    @Test
+    fun `checks unique items constraint providing non-unique nested nested list`() {
+        val cbor = Cbor { }
+        val doubleNestedUniqueItemsListInput = listOf(
+            listOf(listOf("0"), listOf("1", "2"), listOf("6"), listOf("9", "10", "11")),
+            listOf(listOf("2"), listOf("7", "2"), listOf("4"), listOf("5", "6", "5")),
+            listOf(listOf("1"), listOf("1", "2"), listOf("4"), listOf("5", "6", "7")),
+        )
+
+        val requestBytes = cbor.encodeToByteArray(
+            DoubleNestedUniqueItemsConstraintTestRequest.serializer(),
+            DoubleNestedUniqueItemsConstraintTestRequest(doubleNestedUniqueItemsListInput),
+        )
+
+        val response = sendRequest(
+            "$baseUrl/double-nested-unique-items-constraint",
+            "POST",
+            requestBytes,
+            "application/cbor",
+            "application/cbor",
+        )
+        assertIs<HttpResponse<ByteArray>>(response)
+        assertEquals(400, response.statusCode(), "Expected 400")
+
+        val body = cbor.decodeFromByteArray(
+            ErrorResponse.serializer(),
+            response.body(),
+        )
+        assertEquals(400, body.code)
+        assertEquals("`member` must contain only unique items, duplicate values are not allowed", body.message)
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceDataClasses.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceDataClasses.kt
new file mode 100644
index 0000000000..6ea3bb88ac
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceDataClasses.kt
@@ -0,0 +1,76 @@
+package com.test
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ErrorResponse(val code: Int, val message: String)
+
+@Serializable
+data class MalformedPostTestRequest(val input1: Int, val input2: String)
+
+@Serializable
+data class PostTestRequest(val input1: String, val input2: Int)
+
+@Serializable
+data class PostTestResponse(val output1: String? = null, val output2: Int? = null)
+
+@Serializable
+data class AuthTestRequest(val input1: String)
+
+@Serializable
+data class ErrorTestRequest(val input1: String)
+
+@Serializable
+data class HttpError(val msg: String, val num: Int)
+
+@Serializable
+data class RequiredConstraintTestRequest(val requiredInput: String? = null, val notRequiredInput: String? = null)
+
+@Serializable
+data class LengthConstraintTestRequest(
+    val greaterLengthInput: String,
+    val smallerLengthInput: List<String>,
+    val betweenLengthInput: Map<String, String>,
+)
+
+@Serializable
+data class PatternConstraintTestRequest(val patternInput1: String, val patternInput2: String)
+
+@Serializable
+data class RangeConstraintTestRequest(val betweenInput: Int, val greaterInput: Double, val smallerInput: Float)
+
+@Serializable
+data class UniqueItemsConstraintTestRequest(val notUniqueItemsListInput: List<String>, val uniqueItemsListInput: List<String>)
+
+@Serializable
+data class NestedUniqueItemsConstraintTestRequest(val nestedUniqueItemsListInput: List<List<String>>)
+
+@Serializable
+data class DoubleNestedUniqueItemsConstraintTestRequest(val doubleNestedUniqueItemsListInput: List<List<List<String>>>)
+
+@Serializable
+data class HttpLabelTestOutputResponse(val output: String)
+
+@Serializable
+data class HttpQueryTestOutputResponse(val output: String)
+
+@Serializable
+data class HttpStructurePayloadTestStructure(
+    val content1: String,
+    val content2: Int,
+    val content3: Float,
+)
+
+@Serializable
+data class TimestampTestRequestResponse(
+    val default: Double,
+    val dateTime: String,
+    val httpDate: String,
+    val epochSeconds: Double,
+)
+
+@Serializable
+data class JsonNameTestRequest(val requestName: String)
+
+@Serializable
+data class JsonNameTestResponse(val responseName: String)
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceEngineFactoryTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceEngineFactoryTest.kt
new file mode 100644
index 0000000000..560412f1f5
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceEngineFactoryTest.kt
@@ -0,0 +1,51 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import org.junit.jupiter.api.TestInstance
+import java.net.ServerSocket
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class ServiceEngineFactoryTest {
+    val closeGracePeriodMillis = TestParams.CLOSE_GRACE_PERIOD_MILLIS
+    val closeTimeoutMillis = TestParams.CLOSE_TIMEOUT_MILLIS
+    val gracefulWindow = TestParams.GRACEFUL_WINDOW
+    val requestBodyLimit = TestParams.REQUEST_BODY_LIMIT
+    val portListenerTimeout = TestParams.PORT_LISTENER_TIMEOUT
+
+    val projectDir: Path = Paths.get("build/service-cbor-test")
+
+    @Test
+    fun `checks service with netty engine`() {
+        val nettyPort: Int = ServerSocket(0).use { it.localPort }
+        val nettyProc = startService("netty", nettyPort, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(nettyPort, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+        cleanupService(nettyProc, gracefulWindow)
+    }
+
+    @Test
+    fun `checks service with cio engine`() {
+        val cioPort: Int = ServerSocket(0).use { it.localPort }
+        val cioProc = startService("cio", cioPort, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(cioPort, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+        cleanupService(cioProc, gracefulWindow)
+    }
+
+    @Test
+    fun `checks service with jetty jakarta engine`() {
+        val jettyPort: Int = ServerSocket(0).use { it.localPort }
+        val jettyProc = startService("jetty-jakarta", jettyPort, closeGracePeriodMillis, closeTimeoutMillis, requestBodyLimit, projectDir)
+        val ready = waitForPort(jettyPort, portListenerTimeout)
+        assertTrue(ready, "Service did not start within $portListenerTimeout s")
+        cleanupService(jettyProc, gracefulWindow)
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceFileTest.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceFileTest.kt
new file mode 100644
index 0000000000..ffa3a5275b
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/ServiceFileTest.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.test
+
+import java.nio.file.Path
+import java.nio.file.Paths
+import kotlin.io.path.exists
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+class ServiceFileTest {
+    val packageName = "com.cbor"
+    val packagePath = packageName.replace('.', '/')
+
+    val projectDir: Path = Paths.get("build/service-cbor-test")
+
+    @Test
+    fun `generates service and all necessary files`() {
+        assertTrue(projectDir.resolve("build.gradle.kts").exists())
+        assertTrue(projectDir.resolve("settings.gradle.kts").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/Main.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/Routing.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/config/ServiceFrameworkConfig.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/framework/ServiceFramework.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/plugins/ContentTypeGuard.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/plugins/ErrorHandler.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/utils/Logging.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/auth/Authentication.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/auth/Validation.kt").exists())
+
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/model/PostTestRequest.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/model/PostTestResponse.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/serde/PostTestOperationSerializer.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/serde/PostTestOperationDeserializer.kt").exists())
+        assertTrue(projectDir.resolve("src/main/kotlin/$packagePath/operations/PostTestOperation.kt").exists())
+    }
+}
diff --git a/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/utils.kt b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/utils.kt
new file mode 100644
index 0000000000..d4027c18f3
--- /dev/null
+++ b/tests/codegen/service-codegen-tests/src/test/kotlin/com/test/utils.kt
@@ -0,0 +1,248 @@
+package com.test
+
+import aws.smithy.kotlin.runtime.InternalApi
+import aws.smithy.kotlin.runtime.auth.awscredentials.Credentials
+import aws.smithy.kotlin.runtime.auth.awssigning.AwsSignatureType
+import aws.smithy.kotlin.runtime.auth.awssigning.AwsSignedBodyHeader
+import aws.smithy.kotlin.runtime.auth.awssigning.AwsSigningAlgorithm
+import aws.smithy.kotlin.runtime.auth.awssigning.AwsSigningAttributes
+import aws.smithy.kotlin.runtime.auth.awssigning.DefaultAwsSigner
+import aws.smithy.kotlin.runtime.auth.awssigning.HashSpecification
+import aws.smithy.kotlin.runtime.collections.attributesOf
+import aws.smithy.kotlin.runtime.http.HttpBody
+import aws.smithy.kotlin.runtime.http.HttpMethod
+import aws.smithy.kotlin.runtime.http.auth.AwsHttpSigner
+import aws.smithy.kotlin.runtime.http.auth.SignHttpRequest
+import aws.smithy.kotlin.runtime.http.request.HttpRequestBuilder
+import aws.smithy.kotlin.runtime.http.request.headers
+import aws.smithy.kotlin.runtime.http.request.url
+import aws.smithy.kotlin.runtime.net.url.Url
+import aws.smithy.kotlin.runtime.time.Instant
+import kotlinx.coroutines.runBlocking
+import kotlinx.serialization.json.JsonElement
+import org.gradle.testkit.runner.GradleRunner
+import java.io.IOException
+import java.net.Socket
+import java.net.URI
+import java.net.http.HttpClient
+import java.net.http.HttpRequest
+import java.net.http.HttpResponse
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.Locale
+import java.util.concurrent.TimeUnit
+import kotlin.test.assertTrue
+import kotlin.test.fail
+
+internal object TestParams {
+    const val CLOSE_GRACE_PERIOD_MILLIS: Long = 5_000L
+    const val CLOSE_TIMEOUT_MILLIS: Long = 1_000L
+    const val GRACEFUL_WINDOW: Long = CLOSE_GRACE_PERIOD_MILLIS + CLOSE_TIMEOUT_MILLIS
+    const val REQUEST_BODY_LIMIT: Long = 10L * 1024 * 1024
+    const val PORT_LISTENER_TIMEOUT: Long = 60L
+}
+
+internal fun startService(
+    engineFactory: String = "netty",
+    port: Int = 8080,
+    closeGracePeriodMillis: Long = 1000,
+    closeTimeoutMillis: Long = 1000,
+    requestBodyLimit: Long = 10L * 1024 * 1024,
+    projectDir: Path,
+): Process {
+    if (!Files.exists(projectDir.resolve("gradlew"))) {
+        GradleRunner.create()
+            .withProjectDir(projectDir.toFile())
+            .withArguments(
+                "wrapper",
+                "--quiet",
+            )
+            .build()
+    }
+
+    val gradleCmd = if (isWindows()) "gradlew.bat" else "./gradlew"
+    val baseCmd = if (isWindows()) listOf("cmd", "/c", gradleCmd) else listOf(gradleCmd)
+
+    return ProcessBuilder(
+        baseCmd + listOf(
+            "--no-daemon",
+            "--quiet",
+            "run",
+            "--args=--engineFactory $engineFactory " +
+                "--port $port " +
+                "--closeGracePeriodMillis ${closeGracePeriodMillis.toInt()} " +
+                "--closeTimeoutMillis ${closeTimeoutMillis.toInt()} " +
+                "--requestBodyLimit $requestBodyLimit",
+        ),
+    )
+        .directory(projectDir.toFile())
+        .redirectErrorStream(true)
+        .start()
+}
+
+internal fun cleanupService(proc: Process, gracefulWindow: Long = 5_000L) {
+    val okExitCodes = if (isWindows()) {
+        setOf(0, 1, 143, -1, -1073741510)
+    } else {
+        setOf(0, 143)
+    }
+
+    try {
+        proc.destroy()
+        val exited = proc.waitFor(gracefulWindow, TimeUnit.MILLISECONDS)
+
+        if (!exited) {
+            proc.destroyForcibly()
+            fail("Service did not shut down within $gracefulWindow ms")
+        }
+
+        assertTrue(
+            proc.exitValue() in okExitCodes,
+            "Service exited with ${proc.exitValue()} – shutdown not graceful?",
+        )
+    } catch (e: Exception) {
+        proc.destroyForcibly()
+        throw e
+    }
+}
+
+private fun isWindows() = System.getProperty("os.name").lowercase().contains("windows")
+
+internal fun waitForPort(port: Int, timeoutSec: Long = 180): Boolean {
+    val deadline = System.currentTimeMillis() + TimeUnit.SECONDS.toNanos(timeoutSec)
+    while (System.currentTimeMillis() < deadline) {
+        try {
+            Socket("localhost", port).use {
+                return true // Port is available
+            }
+        } catch (e: IOException) {
+            Thread.sleep(100)
+        }
+    }
+    return false
+}
+
+data class AwsSigningOptions(
+    val credentials: Credentials,
+    val service: String, // e.g., "execute-api", "s3", "es", "kinesis"
+    val region: String?, // e.g., "us-west-2" (null when using SigV4A)
+    val algorithm: AwsSigningAlgorithm, // AwsSigningAlgorithm.SIGV4 or SIGV4A
+    val signatureType: AwsSignatureType = AwsSignatureType.HTTP_REQUEST_VIA_HEADERS,
+    val signedBodyHeader: AwsSignedBodyHeader = AwsSignedBodyHeader.NONE,
+    val useDoubleUriEncode: Boolean = true,
+    val normalizeUriPath: Boolean = true,
+)
+
+@OptIn(InternalApi::class)
+internal fun sendRequest(
+    url: String,
+    method: String,
+    data: Any? = null,
+    contentType: String? = null,
+    acceptType: String? = null,
+    bearerToken: String? = null,
+    headers: Map<String, String> = emptyMap(),
+    awsSigning: AwsSigningOptions? = null,
+): HttpResponse<*> {
+    require(!(awsSigning != null && bearerToken != null)) {
+        "Cannot use bearerToken and awsSigning together."
+    }
+    val httpMethod = method.uppercase(Locale.ROOT)
+    require(!(httpMethod in setOf("GET", "HEAD") && data != null)) {
+        "GET/HEAD with a body is not supported."
+    }
+
+    val client = HttpClient.newHttpClient()
+
+    val uri = URI.create(url)
+    val defaultPort = if (uri.scheme.equals("https", true)) 443 else 80
+    val hostHeader = buildString {
+        append(uri.host)
+        if (uri.port != -1 && uri.port != defaultPort) append(":${uri.port}")
+    }
+    val baseHeaders = linkedMapOf<String, String>().apply {
+        put("Host", hostHeader)
+        contentType?.let { put("Content-Type", it) }
+        acceptType?.let { put("Accept", it) }
+        putAll(headers)
+        bearerToken?.let { put("Authorization", "Bearer $it") }
+    }
+
+    val bodyPublisher = when (data) {
+        null -> HttpRequest.BodyPublishers.noBody()
+        is ByteArray -> HttpRequest.BodyPublishers.ofByteArray(data)
+        is String -> HttpRequest.BodyPublishers.ofString(data)
+        is JsonElement -> HttpRequest.BodyPublishers.ofString(data.toString())
+        else -> error("Unsupported body type: ${data::class.qualifiedName}")
+    }
+
+    val signedHeaders = if (awsSigning != null) {
+        requireNotNull(awsSigning.region) { "awsSigning.region is required." }
+
+        val unsigned = awsSigning.signedBodyHeader == AwsSignedBodyHeader.NONE
+        val signer = AwsHttpSigner(
+            AwsHttpSigner.Config().apply {
+                this.signer = DefaultAwsSigner
+                this.service = awsSigning.service
+                this.isUnsignedPayload = unsigned
+                this.algorithm = awsSigning.algorithm
+            },
+        )
+
+        val ktorReq = HttpRequestBuilder().apply {
+            this.method = HttpMethod.parse(httpMethod)
+            url(Url.parse(url))
+            headers {
+                baseHeaders.forEach { (k, v) -> append(k, v) }
+            }
+            if (!unsigned) {
+                body = when {
+                    data is ByteArray -> HttpBody.fromBytes(data)
+                    data is String -> HttpBody.fromBytes(data.toByteArray())
+                    data == null -> HttpBody.Empty
+                    else -> error("Unsupported body type: ${data::class.qualifiedName}")
+                }
+            }
+        }
+
+        val attrs = attributesOf {
+            Credentials to awsSigning.credentials
+            AwsSigningAttributes.SigningRegion to awsSigning.region
+            AwsSigningAttributes.SigningDate to Instant.now()
+            if (unsigned) {
+                AwsSigningAttributes.HashSpecification to HashSpecification.UnsignedPayload
+                AwsSigningAttributes.SignedBodyHeader to AwsSignedBodyHeader.X_AMZ_CONTENT_SHA256
+            } else {
+                AwsSigningAttributes.HashSpecification to HashSpecification.CalculateFromPayload
+                AwsSigningAttributes.SignedBodyHeader to AwsSignedBodyHeader.X_AMZ_CONTENT_SHA256
+            }
+        }
+
+        runBlocking {
+            signer.sign(SignHttpRequest(ktorReq, awsSigning.credentials, attrs))
+        }
+
+        ktorReq.headers.build().entries().associate { (k, vs) -> k to vs.joinToString(",") }
+    } else {
+        baseHeaders
+    }
+
+    val builder = HttpRequest.newBuilder().uri(uri)
+    signedHeaders.forEach { (k, v) ->
+        if (!k.equals("Host", ignoreCase = true)) {
+            builder.header(k, v)
+        }
+    }
+    val request = builder.method(httpMethod, bodyPublisher).build()
+
+    val bodyHandler =
+        if (acceptType?.contains("json", true) == true ||
+            acceptType?.startsWith("text", true) == true
+        ) {
+            HttpResponse.BodyHandlers.ofString()
+        } else {
+            HttpResponse.BodyHandlers.ofByteArray()
+        }
+
+    return client.send(request, bodyHandler)
+}
diff --git a/tests/codegen/waiter-tests/build.gradle.kts b/tests/codegen/waiter-tests/build.gradle.kts
index 72b244a6c9..992a4d471e 100644
--- a/tests/codegen/waiter-tests/build.gradle.kts
+++ b/tests/codegen/waiter-tests/build.gradle.kts
@@ -38,7 +38,7 @@ kotlin.sourceSets.getByName("main") {
 
 tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
     dependsOn(tasks.generateSmithyProjections)
-    kotlinOptions {
+    compilerOptions {
         // generated code has warnings unfortunately
         allWarningsAsErrors = false
     }