diff --git a/AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/StateMachine/CodeGen/Data/HostedUIOptions.swift b/AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/StateMachine/CodeGen/Data/HostedUIOptions.swift
index 90460bb078..161bf320d4 100644
--- a/AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/StateMachine/CodeGen/Data/HostedUIOptions.swift
+++ b/AmplifyPlugins/Auth/Sources/AWSCognitoAuthPlugin/StateMachine/CodeGen/Data/HostedUIOptions.swift
@@ -56,11 +56,11 @@ extension HostedUIOptions: Codable {
         self.providerInfo = try values.decode(HostedUIProviderInfo.self, forKey: .providerInfo)
         self.preferPrivateSession = try values.decode(Bool.self, forKey: .preferPrivateSession)
         self.presentationAnchor = nil
-        self.nonce = try values.decode(String.self, forKey: .nonce)
-        self.language = try values.decode(String.self, forKey: .language)
-        self.loginHint = try values.decode(String.self, forKey: .loginHint)
-        self.prompt = try values.decode(String.self, forKey: .prompt)
-        self.resource = try values.decode(String.self, forKey: .resource)
+        self.nonce = try values.decodeIfPresent(String.self, forKey: .nonce)
+        self.language = try values.decodeIfPresent(String.self, forKey: .language)
+        self.loginHint = try values.decodeIfPresent(String.self, forKey: .loginHint)
+        self.prompt = try values.decodeIfPresent(String.self, forKey: .prompt)
+        self.resource = try values.decodeIfPresent(String.self, forKey: .resource)
     }
 
     func encode(to encoder: Encoder) throws {
@@ -68,11 +68,11 @@ extension HostedUIOptions: Codable {
         try container.encode(scopes, forKey: .scopes)
         try container.encode(providerInfo, forKey: .providerInfo)
         try container.encode(preferPrivateSession, forKey: .preferPrivateSession)
-        try container.encode(nonce, forKey: .nonce)
-        try container.encode(language, forKey: .language)
-        try container.encode(loginHint, forKey: .loginHint)
+        try container.encodeIfPresent(nonce, forKey: .nonce)
+        try container.encodeIfPresent(language, forKey: .language)
+        try container.encodeIfPresent(loginHint, forKey: .loginHint)
         try container.encodeIfPresent(prompt, forKey: .prompt)
-        try container.encode(resource, forKey: .resource)
+        try container.encodeIfPresent(resource, forKey: .resource)
     }
 }
 
diff --git a/AmplifyPlugins/Auth/Tests/AWSCognitoAuthPluginUnitTests/Support/HostedUIOptionsTests.swift b/AmplifyPlugins/Auth/Tests/AWSCognitoAuthPluginUnitTests/Support/HostedUIOptionsTests.swift
new file mode 100644
index 0000000000..76e5e37c4d
--- /dev/null
+++ b/AmplifyPlugins/Auth/Tests/AWSCognitoAuthPluginUnitTests/Support/HostedUIOptionsTests.swift
@@ -0,0 +1,269 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Amplify
+import XCTest
+@testable import AWSCognitoAuthPlugin
+
+class HostedUIOptionsTests: XCTestCase {
+
+    // MARK: - Decoding
+
+    /// - Given: A valid json payload with non-nil values depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The payload is decoded successfully
+    func testHostedUIOptionsDecodeWithNonNullValuesSuccess() {
+        let jsonString =
+        """
+        {
+            "scopes": [
+                "phone",
+                "email",
+                "openid",
+                "profile"
+            ],
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+            let hostedUIOptions = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTAssertEqual(hostedUIOptions.scopes.count, 4)
+            XCTAssertTrue(hostedUIOptions.scopes.contains("phone"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("email"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("openid"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("profile"))
+            XCTAssertEqual(hostedUIOptions.preferPrivateSession, true)
+            XCTAssertNil(hostedUIOptions.presentationAnchor)
+            XCTAssertNil(hostedUIOptions.providerInfo.authProvider)
+            XCTAssertEqual(hostedUIOptions.providerInfo.idpIdentifier, "dummyIdentifier")
+        } catch {
+            XCTFail("Decoding failed with error: \(error)")
+        }
+    }
+
+    /// - Given: A valid json payload with null values for optional fields depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The payload is decoded successfully
+    func testHostedUIOptionsDecodeWithNullValuesSuccess() {
+        let jsonString =
+        """
+        {
+            "scopes": [
+                "phone",
+                "email",
+                "openid",
+                "profile"
+            ],
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true,
+            "nonce": null,
+            "lang": null,
+            "login_hint": null,
+            "prompt": null,
+            "resource": null
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+            let hostedUIOptions = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTAssertEqual(hostedUIOptions.scopes.count, 4)
+            XCTAssertTrue(hostedUIOptions.scopes.contains("phone"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("email"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("openid"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("profile"))
+            XCTAssertEqual(hostedUIOptions.preferPrivateSession, true)
+            XCTAssertNil(hostedUIOptions.presentationAnchor)
+            XCTAssertNil(hostedUIOptions.providerInfo.authProvider)
+            XCTAssertEqual(hostedUIOptions.providerInfo.idpIdentifier, "dummyIdentifier")
+        } catch {
+            XCTFail("Decoding failed with error: \(error)")
+        }
+    }
+
+    /// - Given: A valid json payload with valid values for optional fields depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The payload is decoded successfully
+    func testHostedUIOptionsDecodeWithOptionalValuesSuccess() {
+        let jsonString =
+        """
+        {
+            "scopes": [
+                "phone",
+                "email",
+                "openid",
+                "profile"
+            ],
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true,
+            "nonce": "dummyNonce",
+            "lang": "en",
+            "login_hint": "username",
+            "prompt": "login consent",
+            "resource": "myapp://"
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+            let hostedUIOptions = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTAssertEqual(hostedUIOptions.scopes.count, 4)
+            XCTAssertTrue(hostedUIOptions.scopes.contains("phone"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("email"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("openid"))
+            XCTAssertTrue(hostedUIOptions.scopes.contains("profile"))
+            XCTAssertEqual(hostedUIOptions.preferPrivateSession, true)
+            XCTAssertNil(hostedUIOptions.presentationAnchor)
+            XCTAssertNil(hostedUIOptions.providerInfo.authProvider)
+            XCTAssertEqual(hostedUIOptions.providerInfo.idpIdentifier, "dummyIdentifier")
+            XCTAssertEqual(hostedUIOptions.nonce, "dummyNonce")
+            XCTAssertEqual(hostedUIOptions.language, "en")
+            XCTAssertEqual(hostedUIOptions.loginHint, "username")
+            XCTAssertEqual(hostedUIOptions.prompt, "login consent")
+            XCTAssertEqual(hostedUIOptions.resource, "myapp://")
+        } catch {
+            XCTFail("Decoding failed with error: \(error)")
+        }
+    }
+
+    /// - Given: A valid json payload with null value for scopes field depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The operation should throw an error
+    func testHostedUIOptionsDecodeWithNullScopesFailure() {
+        let jsonString =
+        """
+        {
+            "scopes": null,
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+
+            _ = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTFail("Decoding should not succeed")
+        } catch {
+            XCTAssertNotNil(error)
+            guard case DecodingError.valueNotFound = error else {
+                XCTFail("Error should be of type valueNotFound")
+                return
+            }
+        }
+    }
+
+    /// - Given: A valid json payload with invalid value type for scopes field depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The operation should throw an error
+    func testHostedUIOptionsDecodeWithInvalidScopesFailure() {
+        let jsonString =
+        """
+        {
+            "scopes": "email",
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+
+            _ = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTFail("Decoding should not succeed")
+        } catch {
+            XCTAssertNotNil(error)
+            guard case DecodingError.typeMismatch = error else {
+                XCTFail("Error should be of type typeMismatch")
+                return
+            }
+        }
+    }
+
+    /// - Given: A valid json payload with missing key for scopes field depicting a `HostedUIOptions`
+    /// - When: The payload is decoded
+    /// - Then: The operation should throw an error
+    func testHostedUIOptionsDecodeWithMissingScopesFailure() {
+        let jsonString =
+        """
+        {
+            "providerInfo": {
+                "idpIdentifier": "dummyIdentifier"
+            },
+            "preferPrivateSession": true
+        }
+        """
+
+        do {
+            let data = jsonString.data(using: .utf8)
+            guard let data else {
+                XCTFail("Input JSON is invalid")
+                return
+            }
+
+            _ = try JSONDecoder().decode(
+                HostedUIOptions.self, from: data
+            )
+
+            XCTFail("Decoding should not succeed")
+        } catch {
+            XCTAssertNotNil(error)
+            guard case DecodingError.keyNotFound = error else {
+                XCTFail("Error should be of type typeMismatch")
+                return
+            }
+        }
+    }
+}