fix(mcp): refactor all mcp servers to use multi-session sse transport

packages/klz-payload-mcp/src/index.ts

@@ -7,6 +7,7 @@ import {
     Tool,
 } from "@modelcontextprotocol/sdk/types.js";
 import axios from "axios";
+import crypto from "crypto";
 import https from "https";
 
 const PAYLOAD_URL = process.env.PAYLOAD_URL || "https://klz-cables.com";
@@ -588,17 +589,34 @@ async function run() {
         console.error('KLZ Payload MCP server is running on stdio');
     } else {
         const app = express();
-        let transport: SSEServerTransport | null = null;
+        const transports = new Map<string, SSEServerTransport>();
+
+        app.use((req, _res, next) => {
+            console.error(`${req.method} ${req.url}`);
+            next();
+        });
 
         app.get('/sse', async (req: Request, res: Response) => {
-            console.error('New SSE connection established');
-            transport = new SSEServerTransport('/message', res);
+            const sessionId = crypto.randomUUID();
+            console.error(`New SSE connection: ${sessionId}`);
+            const transport = new SSEServerTransport(`/message/${sessionId}`, res);
+            transports.set(sessionId, transport);
+
+            req.on('close', () => {
+                console.error(`SSE connection closed: ${sessionId}`);
+                transports.delete(sessionId);
+            });
+
             await server.connect(transport);
         });
 
-        app.post('/message', async (req: Request, res: Response) => {
+        app.post('/message/:sessionId', async (req: Request, res: Response) => {
+            const sessionId = req.params.sessionId;
+            const transport = transports.get(sessionId as string);
+
             if (!transport) {
-                res.status(400).send('No active SSE connection');
+                console.error(`No transport found for session: ${sessionId}`);
+                res.status(400).send('No active SSE connection for this session');
                 return;
             }
             await transport.handlePostMessage(req, res);