WIP: Add session ID to exchange

Signed-off-by: Dariusz Jędrzejczyk <[email protected]>

Author: chemicL

mcp/src/main/java/io/modelcontextprotocol/server/McpAsyncServerExchange.java

@@ -27,6 +27,8 @@
  */
 public class McpAsyncServerExchange {
 
+	private final String sessionId;
+
 	private final McpSession session;
 
 	private final McpSchema.ClientCapabilities clientCapabilities;
@@ -55,13 +57,16 @@ public class McpAsyncServerExchange {
 	 * @param clientCapabilities The client capabilities that define the supported
 	 * features and functionality.
 	 * @param clientInfo The client implementation information.
+	 * @deprecated Use
+	 * {@link #McpAsyncServerExchange(String, McpSession, McpSchema.ClientCapabilities, McpSchema.Implementation, McpTransportContext)}
 	 */
+	@Deprecated
 	public McpAsyncServerExchange(McpSession session, McpSchema.ClientCapabilities clientCapabilities,
 			McpSchema.Implementation clientInfo) {
 		this.session = session;
 		this.clientCapabilities = clientCapabilities;
 		this.clientInfo = clientInfo;
-		this.transportContext = new DefaultMcpTransportContext();
+		this.transportContext = McpTransportContext.EMPTY;
 	}
 
 	/**
@@ -73,8 +78,9 @@ public McpAsyncServerExchange(McpSession session, McpSchema.ClientCapabilities c
 	 * transport
 	 * @param clientInfo The client implementation information.
 	 */
-	public McpAsyncServerExchange(McpSession session, McpSchema.ClientCapabilities clientCapabilities,
+	public McpAsyncServerExchange(String sessionId, McpSession session, McpSchema.ClientCapabilities clientCapabilities,
 			McpSchema.Implementation clientInfo, McpTransportContext transportContext) {
+		this.sessionId = sessionId;
 		this.session = session;
 		this.clientCapabilities = clientCapabilities;
 		this.clientInfo = clientInfo;
@@ -101,6 +107,10 @@ public McpTransportContext transportContext() {
 		return this.transportContext;
 	}
 
+	public String sessionId() {
+		return this.sessionId;
+	}
+
 	/**
 	 * Create a new message using the sampling capabilities of the client. The Model
 	 * Context Protocol (MCP) provides a standardized way for servers to request LLM

mcp/src/main/java/io/modelcontextprotocol/server/McpSyncServerExchange.java

@@ -28,6 +28,10 @@ public McpSyncServerExchange(McpAsyncServerExchange exchange) {
 		this.exchange = exchange;
 	}
 
+	public String sessionId() {
+		return this.exchange.sessionId();
+	}
+
 	/**
 	 * Get the client capabilities that define the supported features and functionality.
 	 * @return The client capabilities

mcp/src/main/java/io/modelcontextprotocol/spec/McpServerSession.java

@@ -246,7 +246,8 @@ private Mono<Void> handleIncomingNotification(McpSchema.JSONRPCNotification noti
 		return Mono.defer(() -> {
 			if (McpSchema.METHOD_NOTIFICATION_INITIALIZED.equals(notification.method())) {
 				this.state.lazySet(STATE_INITIALIZED);
-				exchangeSink.tryEmitValue(new McpAsyncServerExchange(this, clientCapabilities.get(), clientInfo.get()));
+				exchangeSink.tryEmitValue(new McpAsyncServerExchange(this.id, this, clientCapabilities.get(),
+						clientInfo.get(), McpTransportContext.EMPTY));
 				return this.initNotificationHandler.handle();
 			}
 

mcp/src/main/java/io/modelcontextprotocol/spec/McpStreamableServerSession.java

@@ -118,7 +118,7 @@ public Mono<Void> responseStream(McpSchema.JSONRPCRequest jsonrpcRequest, McpSer
 									error.message(), error.data())));
 			}
 			return requestHandler
-				.handle(new McpAsyncServerExchange(stream, clientCapabilities.get(), clientInfo.get(),
+				.handle(new McpAsyncServerExchange(this.id, stream, clientCapabilities.get(), clientInfo.get(),
 						transportContext), jsonrpcRequest.params())
 				.map(result -> new McpSchema.JSONRPCResponse(McpSchema.JSONRPC_VERSION, jsonrpcRequest.id(), result,
 						null))
@@ -137,7 +137,7 @@ public Mono<Void> accept(McpSchema.JSONRPCNotification notification) {
 			}
 			McpStreamableServerSessionStream listeningStream = this.listeningStreamRef.get();
 			return notificationHandler.handle(
-					new McpAsyncServerExchange(
+					new McpAsyncServerExchange(this.id,
 							listeningStream != null ? listeningStream : MissingMcpTransportSession.INSTANCE,
 							this.clientCapabilities.get(), this.clientInfo.get(), transportContext),
 					notification.params());