Remove closed sessions from list in WebMvcSseServerTransport

Author: denniskawurek

mcp-spring/mcp-spring-webmvc/src/main/java/io/modelcontextprotocol/server/transport/WebMvcSseServerTransport.java

@@ -218,6 +218,14 @@ private ServerResponse handleSseConnection(ServerRequest request) {
 		// Send initial endpoint event
 		try {
 			return ServerResponse.sse(sseBuilder -> {
+				sseBuilder.onComplete(() -> {
+					logger.debug("SSE connection completed for session: {}", sessionId);
+					sessions.remove(sessionId);
+				});
+				sseBuilder.onTimeout(() -> {
+					logger.debug("SSE connection timed out for session: {}", sessionId);
+					sessions.remove(sessionId);
+				});
 
 				ClientSession session = new ClientSession(sessionId, sseBuilder);
 				this.sessions.put(sessionId, session);