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chore: Add createSession method in McpAsyncClient #676

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chore: Add createSession method in McpAsyncClient #676

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chore: Add createSession method in McpAsyncClient
He-Pin Nov 19, 2025
c9c59aa
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He-Pin Nov 19, 2025
6e158b6
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He-Pin Nov 19, 2025
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13 changes: 11 additions & 2 deletions mcp-core/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@
import org.slf4j.LoggerFactory;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.util.context.ContextView;

/**
* The Model Context Protocol (MCP) client implementation that provides asynchronous
Expand Down Expand Up @@ -314,13 +315,21 @@ public class McpAsyncClient {
};

this.initializer = new LifecycleInitializer(clientCapabilities, clientInfo, transport.protocolVersions(),
initializationTimeout, ctx -> new McpClientSession(requestTimeout, transport, requestHandlers,
notificationHandlers, con -> con.contextWrite(ctx)),
initializationTimeout, ctx -> createSession(ctx, requestTimeout, requestHandlers, notificationHandlers),
postInitializationHook);

this.transport.setExceptionHandler(this.initializer::handleException);
}

/**
* An extension point to create a custom McpClientSession with additional context.
*/
protected McpClientSession createSession(ContextView ctx, Duration requestTimeout,
Map<String, RequestHandler<?>> requestHandlers, Map<String, NotificationHandler> notificationHandlers) {
return new McpClientSession(requestTimeout, transport, requestHandlers, notificationHandlers,
con -> con.contextWrite(ctx));
}

/**
* Get the current initialization result.
* @return the initialization result.
Expand Down
10 changes: 7 additions & 3 deletions mcp-core/src/main/java/io/modelcontextprotocol/spec/McpClientSession.java
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Expand Up @@ -145,7 +145,11 @@ private void dismissPendingResponses() {
this.pendingResponses.clear();
}

private void handle(McpSchema.JSONRPCMessage message) {
/**
* An extension point for handling incoming JSON-RPC messages.
* @param message The incoming JSON-RPC message
*/
protected void handle(McpSchema.JSONRPCMessage message) {
if (message instanceof McpSchema.JSONRPCResponse response) {
logger.debug("Received response: {}", response);
if (response.id() != null) {
Expand Down Expand Up @@ -198,7 +202,7 @@ else if (message instanceof McpSchema.JSONRPCNotification notification) {
* @param request The incoming JSON-RPC request
* @return A Mono containing the JSON-RPC response
*/
private Mono<McpSchema.JSONRPCResponse> handleIncomingRequest(McpSchema.JSONRPCRequest request) {
protected Mono<McpSchema.JSONRPCResponse> handleIncomingRequest(McpSchema.JSONRPCRequest request) {
return Mono.defer(() -> {
var handler = this.requestHandlers.get(request.method());
if (handler == null) {
Expand Down Expand Up @@ -231,7 +235,7 @@ private MethodNotFoundError getMethodNotFoundError(String method) {
* @param notification The incoming JSON-RPC notification
* @return A Mono that completes when the notification is processed
*/
private Mono<Void> handleIncomingNotification(McpSchema.JSONRPCNotification notification) {
protected Mono<Void> handleIncomingNotification(McpSchema.JSONRPCNotification notification) {
return Mono.defer(() -> {
var handler = notificationHandlers.get(notification.method());
if (handler == null) {
Expand Down