Merged with current main

Author: scottslewis

mcp-core/pom.xml

@@ -105,6 +105,7 @@
             <version>0.17.0-SNAPSHOT</version>
             <scope>test</scope>
         </dependency>
+
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-webmvc</artifactId>

mcp-core/src/main/java/io/modelcontextprotocol/client/LifecycleInitializer.java

@@ -287,7 +287,9 @@ public <T> Mono<T> withInitialization(String actionName, Function<Initialization
 					this.initializationRef.compareAndSet(newInit, null);
 					return Mono.error(new RuntimeException("Client failed to initialize " + actionName, ex));
 				})
-				.flatMap(operation);
+				.flatMap(res -> operation.apply(res)
+					.contextWrite(c -> c.put(McpAsyncClient.NEGOTIATED_PROTOCOL_VERSION,
+							res.initializeResult().protocolVersion())));
 		});
 	}
 
@@ -319,6 +321,8 @@ private Mono<McpSchema.InitializeResult> doInitialize(DefaultInitialization init
 			}
 
 			return mcpClientSession.sendNotification(McpSchema.METHOD_NOTIFICATION_INITIALIZED, null)
+				.contextWrite(
+						c -> c.put(McpAsyncClient.NEGOTIATED_PROTOCOL_VERSION, initializeResult.protocolVersion()))
 				.thenReturn(initializeResult);
 		}).flatMap(initializeResult -> {
 			initialization.cacheResult(initializeResult);

mcp-core/src/main/java/io/modelcontextprotocol/client/McpClient.java

@@ -13,9 +13,9 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-import io.modelcontextprotocol.common.McpTransportContext;
 import io.modelcontextprotocol.json.McpJsonDefaults;
 import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
+import io.modelcontextprotocol.common.McpTransportContext;
 import io.modelcontextprotocol.spec.McpClientTransport;
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.ClientCapabilities;

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientSseClientTransport.java

@@ -18,7 +18,6 @@
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import io.modelcontextprotocol.client.transport.ResponseSubscribers.ResponseEvent;
 import io.modelcontextprotocol.client.transport.customizer.McpAsyncHttpClientRequestCustomizer;
 import io.modelcontextprotocol.client.transport.customizer.McpSyncHttpClientRequestCustomizer;
@@ -28,7 +27,6 @@
 import io.modelcontextprotocol.json.TypeRef;
 import io.modelcontextprotocol.spec.HttpHeaders;
 import io.modelcontextprotocol.spec.McpClientTransport;
-import io.modelcontextprotocol.spec.McpError;
 import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.JSONRPCMessage;
 import io.modelcontextprotocol.spec.McpTransportException;

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/HttpClientStreamableHttpTransport.java

@@ -20,6 +20,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 
+import io.modelcontextprotocol.client.McpAsyncClient;
 import io.modelcontextprotocol.client.transport.ResponseSubscribers.ResponseEvent;
 import io.modelcontextprotocol.client.transport.customizer.McpAsyncHttpClientRequestCustomizer;
 import io.modelcontextprotocol.client.transport.customizer.McpSyncHttpClientRequestCustomizer;
@@ -194,7 +195,9 @@ private Publisher<Void> createDelete(String sessionId) {
 				.uri(uri)
 				.header("Cache-Control", "no-cache")
 				.header(HttpHeaders.MCP_SESSION_ID, sessionId)
-				.header(HttpHeaders.PROTOCOL_VERSION, this.latestSupportedProtocolVersion)
+				.header(HttpHeaders.PROTOCOL_VERSION,
+						ctx.getOrDefault(McpAsyncClient.NEGOTIATED_PROTOCOL_VERSION,
+								this.latestSupportedProtocolVersion))
 				.DELETE();
 			var transportContext = ctx.getOrDefault(McpTransportContext.KEY, McpTransportContext.EMPTY);
 			return Mono.from(this.httpRequestCustomizer.customize(builder, "DELETE", uri, null, transportContext));
@@ -265,7 +268,9 @@ private Mono<Disposable> reconnect(McpTransportStream<Disposable> stream) {
 				var builder = requestBuilder.uri(uri)
 					.header(HttpHeaders.ACCEPT, TEXT_EVENT_STREAM)
 					.header("Cache-Control", "no-cache")
-					.header(HttpHeaders.PROTOCOL_VERSION, this.latestSupportedProtocolVersion)
+					.header(HttpHeaders.PROTOCOL_VERSION,
+							connectionCtx.getOrDefault(McpAsyncClient.NEGOTIATED_PROTOCOL_VERSION,
+									this.latestSupportedProtocolVersion))
 					.GET();
 				var transportContext = connectionCtx.getOrDefault(McpTransportContext.KEY, McpTransportContext.EMPTY);
 				return Mono.from(this.httpRequestCustomizer.customize(builder, "GET", uri, null, transportContext));
@@ -440,7 +445,9 @@ public Mono<Void> sendMessage(McpSchema.JSONRPCMessage sentMessage) {
 					.header(HttpHeaders.ACCEPT, APPLICATION_JSON + ", " + TEXT_EVENT_STREAM)
 					.header(HttpHeaders.CONTENT_TYPE, APPLICATION_JSON)
 					.header(HttpHeaders.CACHE_CONTROL, "no-cache")
-					.header(HttpHeaders.PROTOCOL_VERSION, this.latestSupportedProtocolVersion)
+					.header(HttpHeaders.PROTOCOL_VERSION,
+							ctx.getOrDefault(McpAsyncClient.NEGOTIATED_PROTOCOL_VERSION,
+									this.latestSupportedProtocolVersion))
 					.POST(HttpRequest.BodyPublishers.ofString(jsonBody));
 				var transportContext = ctx.getOrDefault(McpTransportContext.KEY, McpTransportContext.EMPTY);
 				return Mono
@@ -814,9 +821,10 @@ public Builder supportedProtocolVersions(List<String> supportedProtocolVersions)
 		 */
 		public HttpClientStreamableHttpTransport build() {
 			HttpClient httpClient = this.clientBuilder.connectTimeout(this.connectTimeout).build();
-			return new HttpClientStreamableHttpTransport(jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper,
-					httpClient, requestBuilder, baseUri, endpoint, resumableStreams, openConnectionOnStartup,
-					httpRequestCustomizer, supportedProtocolVersions);
+			return new HttpClientStreamableHttpTransport(
+					jsonMapper == null ? McpJsonDefaults.getDefaultMcpJsonMapper() : jsonMapper, httpClient,
+					requestBuilder, baseUri, endpoint, resumableStreams, openConnectionOnStartup, httpRequestCustomizer,
+					supportedProtocolVersions);
 		}
 
 	}

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/ServerParameters.java

@@ -13,7 +13,6 @@
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
-
 import io.modelcontextprotocol.util.Assert;
 
 /**

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/customizer/McpAsyncHttpClientRequestCustomizer.java

@@ -8,12 +8,12 @@
 import java.net.http.HttpRequest;
 
 import org.reactivestreams.Publisher;
-
-import io.modelcontextprotocol.common.McpTransportContext;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Schedulers;
 import reactor.util.annotation.Nullable;
 
+import io.modelcontextprotocol.common.McpTransportContext;
+
 /**
  * Customize {@link HttpRequest.Builder} before executing the request, in either SSE or
  * Streamable HTTP transport.

mcp-core/src/main/java/io/modelcontextprotocol/client/transport/customizer/McpSyncHttpClientRequestCustomizer.java

@@ -7,9 +7,10 @@
 import java.net.URI;
 import java.net.http.HttpRequest;
 
+import reactor.util.annotation.Nullable;
+
 import io.modelcontextprotocol.client.McpClient.SyncSpec;
 import io.modelcontextprotocol.common.McpTransportContext;
-import reactor.util.annotation.Nullable;
 
 /**
  * Customize {@link HttpRequest.Builder} before executing the request, either in SSE or

mcp-core/src/main/java/io/modelcontextprotocol/server/DefaultMcpStatelessServerHandler.java

@@ -4,16 +4,15 @@
 
 package io.modelcontextprotocol.server;
 
-import java.util.Map;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import io.modelcontextprotocol.common.McpTransportContext;
 import io.modelcontextprotocol.spec.McpError;
 import io.modelcontextprotocol.spec.McpSchema;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Mono;
 
+import java.util.Map;
+
 class DefaultMcpStatelessServerHandler implements McpStatelessServerHandler {
 
 	private static final Logger logger = LoggerFactory.getLogger(DefaultMcpStatelessServerHandler.class);

mcp-core/src/main/java/io/modelcontextprotocol/server/McpAsyncServer.java

@@ -4,8 +4,6 @@
 
 package io.modelcontextprotocol.server;
 
-import static io.modelcontextprotocol.spec.McpError.RESOURCE_NOT_FOUND;
-
 import java.time.Duration;
 import java.util.HashMap;
 import java.util.List;
@@ -16,9 +14,6 @@
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.function.BiFunction;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import io.modelcontextprotocol.json.McpJsonMapper;
 import io.modelcontextprotocol.json.TypeRef;
 import io.modelcontextprotocol.json.schema.JsonSchemaValidator;
@@ -43,9 +38,13 @@
 import io.modelcontextprotocol.util.DefaultMcpUriTemplateManagerFactory;
 import io.modelcontextprotocol.util.McpUriTemplateManagerFactory;
 import io.modelcontextprotocol.util.Utils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import static io.modelcontextprotocol.spec.McpError.RESOURCE_NOT_FOUND;
+
 /**
  * The Model Context Protocol (MCP) server implementation that provides asynchronous
  * communication using Project Reactor's Mono and Flux types.