diff --git a/server/src/index.ts b/server/src/index.ts index c967b60c7..73288f672 100644 --- a/server/src/index.ts +++ b/server/src/index.ts @@ -48,7 +48,8 @@ app.use((req, res, next) => { next(); }); -const webAppTransports: Map = new Map(); // Transports by sessionId +const webAppTransports: Map = new Map(); // Web app transports by web app sessionId +const serverTransports: Map = new Map(); // Server Transports by web app sessionId const createTransport = async (req: express.Request): Promise => { const query = req.query; @@ -137,8 +138,6 @@ const createTransport = async (req: express.Request): Promise => { } }; -let backingServerTransport: Transport | undefined; - app.get("/mcp", async (req, res) => { const sessionId = req.headers["mcp-session-id"] as string; console.log(`Received GET message for sessionId ${sessionId}`); @@ -161,12 +160,12 @@ app.get("/mcp", async (req, res) => { app.post("/mcp", async (req, res) => { const sessionId = req.headers["mcp-session-id"] as string | undefined; console.log(`Received POST message for sessionId ${sessionId}`); + let serverTransport: Transport | undefined; if (!sessionId) { try { console.log("New streamable-http connection"); try { - await backingServerTransport?.close(); - backingServerTransport = await createTransport(req); + serverTransport = await createTransport(req); } catch (error) { if (error instanceof SseError && error.code === 401) { console.error( @@ -180,12 +179,13 @@ app.post("/mcp", async (req, res) => { throw error; } - console.log("Connected MCP client to backing server transport"); + console.log("Connected MCP client to server transport"); const webAppTransport = new StreamableHTTPServerTransport({ sessionIdGenerator: randomUUID, onsessioninitialized: (sessionId) => { webAppTransports.set(sessionId, webAppTransport); + serverTransports.set(sessionId, serverTransport!); console.log("Created streamable web app transport " + sessionId); }, }); @@ -194,7 +194,7 @@ app.post("/mcp", async (req, res) => { mcpProxy({ transportToClient: webAppTransport, - transportToServer: backingServerTransport, + transportToServer: serverTransport, }); await (webAppTransport as StreamableHTTPServerTransport).handleRequest( @@ -229,10 +229,9 @@ app.post("/mcp", async (req, res) => { app.get("/stdio", async (req, res) => { try { console.log("New connection"); - + let serverTransport: Transport | undefined; try { - await backingServerTransport?.close(); - backingServerTransport = await createTransport(req); + serverTransport = await createTransport(req); } catch (error) { if (error instanceof SseError && error.code === 401) { console.error( @@ -250,26 +249,24 @@ app.get("/stdio", async (req, res) => { const webAppTransport = new SSEServerTransport("/message", res); webAppTransports.set(webAppTransport.sessionId, webAppTransport); - - console.log("Created web app transport"); + serverTransports.set(webAppTransport.sessionId, serverTransport); + console.log("Created client/server transports"); await webAppTransport.start(); - (backingServerTransport as StdioClientTransport).stderr!.on( - "data", - (chunk) => { - webAppTransport.send({ - jsonrpc: "2.0", - method: "notifications/stderr", - params: { - content: chunk.toString(), - }, - }); - }, - ); + + (serverTransport as StdioClientTransport).stderr!.on("data", (chunk) => { + webAppTransport.send({ + jsonrpc: "2.0", + method: "notifications/stderr", + params: { + content: chunk.toString(), + }, + }); + }); mcpProxy({ transportToClient: webAppTransport, - transportToServer: backingServerTransport, + transportToServer: serverTransport, }); console.log("Set up MCP proxy"); @@ -284,10 +281,9 @@ app.get("/sse", async (req, res) => { console.log( "New SSE connection. NOTE: The sse transport is deprecated and has been replaced by streamable-http", ); - + let serverTransport: Transport | undefined; try { - await backingServerTransport?.close(); - backingServerTransport = await createTransport(req); + serverTransport = await createTransport(req); } catch (error) { if (error instanceof SseError && error.code === 401) { console.error( @@ -305,13 +301,15 @@ app.get("/sse", async (req, res) => { const webAppTransport = new SSEServerTransport("/message", res); webAppTransports.set(webAppTransport.sessionId, webAppTransport); - console.log("Created web app transport"); + console.log("Created client transport"); + serverTransports.set(webAppTransport.sessionId, serverTransport); + console.log("Created server transport"); await webAppTransport.start(); mcpProxy({ transportToClient: webAppTransport, - transportToServer: backingServerTransport, + transportToServer: serverTransport, }); console.log("Set up MCP proxy");