feat: support Streamable HTTP transport for downstream (#32)

package.json

@@ -23,7 +23,7 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "@modelcontextprotocol/sdk": "^1.9.0",
+    "@modelcontextprotocol/sdk": "^1.10.2",
     "@radix-ui/react-accordion": "^1.2.3",
     "@radix-ui/react-slot": "^1.1.2",
     "@shadcn/ui": "^0.0.4",

pnpm-lock.yaml

@@ -9,8 +9,8 @@ importers:
   .:
     dependencies:
       '@modelcontextprotocol/sdk':
-        specifier: ^1.9.0
-        version: 1.9.0
+        specifier: ^1.10.2
+        version: 1.10.2
       '@radix-ui/react-accordion':
         specifier: ^1.2.3
         version: 1.2.3(@types/react-dom@19.0.4(@types/react@19.0.12))(@types/react@19.0.12)(react-dom@19.1.0(react@19.1.0))(react@19.1.0)
@@ -867,8 +867,8 @@ packages:
   '@jridgewell/trace-mapping@0.3.9':
     resolution: {integrity: sha512-3Belt6tdc8bPgAtbcmdtNJlirVoTmEb5e2gC94PnkwEW9jI6CAHUeoG85tjWP5WquqfavoMtMwiG4P926ZKKuQ==}
 
-  '@modelcontextprotocol/sdk@1.9.0':
-    resolution: {integrity: sha512-Jq2EUCQpe0iyO5FGpzVYDNFR6oR53AIrwph9yWl7uSc7IWUMsrmpmSaTGra5hQNunXpM+9oit85p924jWuHzUA==}
+  '@modelcontextprotocol/sdk@1.10.2':
+    resolution: {integrity: sha512-rb6AMp2DR4SN+kc6L1ta2NCpApyA9WYNx3CrTSZvGxq9wH71bRur+zRqPfg0vQ9mjywR7qZdX2RGHOPq3ss+tA==}
     engines: {node: '>=18'}
 
   '@next/env@15.2.4':
@@ -4268,7 +4268,7 @@ snapshots:
       '@jridgewell/resolve-uri': 3.1.2
       '@jridgewell/sourcemap-codec': 1.5.0
 
-  '@modelcontextprotocol/sdk@1.9.0':
+  '@modelcontextprotocol/sdk@1.10.2':
     dependencies:
       content-type: 1.0.5
       cors: 2.8.5

src/server.ts

@@ -4,7 +4,12 @@ import path from 'path';
 import { initMcpServer } from './services/mcpService.js';
 import { initMiddlewares } from './middlewares/index.js';
 import { initRoutes } from './routes/index.js';
-import { handleSseConnection, handleSseMessage } from './services/sseService.js';
+import {
+  handleSseConnection,
+  handleSseMessage,
+  handleMcpPostRequest,
+  handleMcpOtherRequest,
+} from './services/sseService.js';
 import { migrateUserData } from './utils/migration.js';
 import { initializeDefaultUser } from './models/User.js';
 
@@ -34,6 +39,9 @@ export class AppServer {
           console.log('MCP server initialized successfully');
           this.app.get('/sse/:group?', (req, res) => handleSseConnection(req, res));
           this.app.post('/messages', handleSseMessage);
+          this.app.post('/mcp/:group?', handleMcpPostRequest);
+          this.app.get('/mcp/:group?', handleMcpOtherRequest);
+          this.app.delete('/mcp/:group?', handleMcpOtherRequest);
         })
         .catch((error) => {
           console.error('Error initializing MCP server:', error);

src/services/sseService.ts

@@ -1,9 +1,13 @@
 import { Request, Response } from 'express';
+import { randomUUID } from 'node:crypto';
+import { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
 import { SSEServerTransport } from '@modelcontextprotocol/sdk/server/sse.js';
+import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
+import { isInitializeRequest } from '@modelcontextprotocol/sdk/types.js';
 import { getMcpServer } from './mcpService.js';
 import { loadSettings } from '../config/index.js';
 
-const transports: { [sessionId: string]: { transport: SSEServerTransport; group: string } } = {};
+const transports: { [sessionId: string]: { transport: Transport; group: string } } = {};
 
 export const getGroup = (sessionId: string): string => {
   return transports[sessionId]?.group || '';
@@ -44,13 +48,72 @@ export const handleSseMessage = async (req: Request, res: Response): Promise<voi
   req.query.group = group;
   console.log(`Received message for sessionId: ${sessionId} in group: ${group}`);
   if (transport) {
-    await transport.handlePostMessage(req, res);
+    await (transport as SSEServerTransport).handlePostMessage(req, res);
   } else {
     console.error(`No transport found for sessionId: ${sessionId}`);
     res.status(400).send('No transport found for sessionId');
   }
 };
 
+export const handleMcpPostRequest = async (req: Request, res: Response): Promise<void> => {
+  console.log('Handling MCP post request');
+  const sessionId = req.headers['mcp-session-id'] as string | undefined;
+  const group = req.params.group;
+  const settings = loadSettings();
+  const routingConfig = settings.systemConfig?.routing || {
+    enableGlobalRoute: true,
+    enableGroupNameRoute: true,
+  };
+  if (!group && !routingConfig.enableGlobalRoute) {
+    res.status(403).send('Global routes are disabled. Please specify a group ID.');
+    return;
+  }
+
+  let transport: StreamableHTTPServerTransport;
+  if (sessionId && transports[sessionId]) {
+    transport = transports[sessionId].transport as StreamableHTTPServerTransport;
+  } else if (!sessionId && isInitializeRequest(req.body)) {
+    transport = new StreamableHTTPServerTransport({
+      sessionIdGenerator: () => randomUUID(),
+      onsessioninitialized: (sessionId) => {
+        transports[sessionId] = { transport, group };
+      },
+    });
+
+    transport.onclose = () => {
+      if (transport.sessionId) {
+        delete transports[transport.sessionId];
+      }
+    };
+
+    await getMcpServer().connect(transport);
+  } else {
+    res.status(400).json({
+      jsonrpc: '2.0',
+      error: {
+        code: -32000,
+        message: 'Bad Request: No valid session ID provided',
+      },
+      id: null,
+    });
+    return;
+  }
+
+  await transport.handleRequest(req, res, req.body);
+};
+
+export const handleMcpOtherRequest = async (req: Request, res: Response) => {
+  console.log('Handling MCP other request');
+  const sessionId = req.headers['mcp-session-id'] as string | undefined;
+  if (!sessionId || !transports[sessionId]) {
+    res.status(400).send('Invalid or missing session ID');
+    return;
+  }
+
+  const { transport } = transports[sessionId];
+  await (transport as StreamableHTTPServerTransport).handleRequest(req, res);
+};
+
 export const getConnectionCount = (): number => {
   return Object.keys(transports).length;
 };