handle session termination

src/examples/server/simpleStreamableHttp.ts

@@ -255,6 +255,15 @@ app.post('/mcp', async (req: Request, res: Response) => {
         }
       });
 
+      // Set up onclose handler to clean up transport when closed
+      transport.onclose = () => {
+        const sid = transport.sessionId;
+        if (sid && transports[sid]) {
+          console.log(`Transport closed for session ${sid}, removing from transports map`);
+          delete transports[sid];
+        }
+      };
+
       // Connect the transport to the MCP server BEFORE handling the request
       // so responses can flow back through the same transport
       await server.connect(transport);
@@ -312,6 +321,27 @@ app.get('/mcp', async (req: Request, res: Response) => {
   await transport.handleRequest(req, res);
 });
 
+// Handle DELETE requests for session termination (according to MCP spec)
+app.delete('/mcp', async (req: Request, res: Response) => {
+  const sessionId = req.headers['mcp-session-id'] as string | undefined;
+  if (!sessionId || !transports[sessionId]) {
+    res.status(400).send('Invalid or missing session ID');
+    return;
+  }
+
+  console.log(`Received session termination request for session ${sessionId}`);
+
+  try {
+    const transport = transports[sessionId];
+    await transport.handleRequest(req, res);
+  } catch (error) {
+    console.error('Error handling session termination:', error);
+    if (!res.headersSent) {
+      res.status(500).send('Error processing session termination');
+    }
+  }
+});
+
 // Start the server
 const PORT = 3000;
 app.listen(PORT, () => {
@@ -343,6 +373,18 @@ app.listen(PORT, () => {
 // Handle server shutdown
 process.on('SIGINT', async () => {
   console.log('Shutting down server...');
+
+  // Close all active transports to properly clean up resources
+  for (const sessionId in transports) {
+    try {
+      console.log(`Closing transport for session ${sessionId}`);
+      await transports[sessionId].close();
+      delete transports[sessionId];
+    } catch (error) {
+      console.error(`Error closing transport for session ${sessionId}:`, error);
+    }
+  }
   await server.close();
+  console.log('Server shutdown complete');
   process.exit(0);
 });