"use strict"; var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { if (k2 === undefined) k2 = k; var desc = Object.getOwnPropertyDescriptor(m, k); if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) { desc = { enumerable: true, get: function() { return m[k]; } }; } Object.defineProperty(o, k2, desc); }) : (function(o, m, k, k2) { if (k2 === undefined) k2 = k; o[k2] = m[k]; })); var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) { Object.defineProperty(o, "default", { enumerable: true, value: v }); }) : function(o, v) { o["default"] = v; }); var __importStar = (this && this.__importStar) || function (mod) { if (mod && mod.__esModule) return mod; var result = {}; if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); __setModuleDefault(result, mod); return result; }; Object.defineProperty(exports, "__esModule", { value: true }); const node_crypto_1 = require("node:crypto"); const mcp_js_1 = require("../../server/mcp.js"); const streamableHttp_js_1 = require("../../server/streamableHttp.js"); const z = __importStar(require("zod/v4")); const types_js_1 = require("../../types.js"); const express_js_1 = require("../../server/express.js"); // Create an MCP server with implementation details const getServer = () => { const server = new mcp_js_1.McpServer({ name: 'json-response-streamable-http-server', version: '1.0.0' }, { capabilities: { logging: {} } }); // Register a simple tool that returns a greeting server.registerTool('greet', { description: 'A simple greeting tool', inputSchema: { name: z.string().describe('Name to greet') } }, async ({ name }) => { return { content: [ { type: 'text', text: `Hello, ${name}!` } ] }; }); // Register a tool that sends multiple greetings with notifications server.registerTool('multi-greet', { description: 'A tool that sends different greetings with delays between them', inputSchema: { name: z.string().describe('Name to greet') } }, async ({ name }, extra) => { const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms)); await server.sendLoggingMessage({ level: 'debug', data: `Starting multi-greet for ${name}` }, extra.sessionId); await sleep(1000); // Wait 1 second before first greeting await server.sendLoggingMessage({ level: 'info', data: `Sending first greeting to ${name}` }, extra.sessionId); await sleep(1000); // Wait another second before second greeting await server.sendLoggingMessage({ level: 'info', data: `Sending second greeting to ${name}` }, extra.sessionId); return { content: [ { type: 'text', text: `Good morning, ${name}!` } ] }; }); return server; }; const app = (0, express_js_1.createMcpExpressApp)(); // Close sessions that have been idle for IDLE_MS, and keep at most MAX_SESSIONS open const IDLE_MS = 30 * 60000; const MAX_SESSIONS = 1000; const sessions = new Map(); // Count open responses so a long-running request is not treated as idle const trackResponse = (session, res) => { if (!res.socket || res.destroyed) return; session.open++; res.on('close', () => { session.open--; session.lastActive = Date.now(); }); }; // Close sessions with nothing open and no activity for IDLE_MS setInterval(() => { const cutoff = Date.now() - IDLE_MS; for (const { transport, open, lastActive } of sessions.values()) { if (open === 0 && lastActive < cutoff) transport.close().catch(console.error); } }, 60000).unref(); app.post('/mcp', async (req, res) => { console.log('Received MCP request:', req.body); try { // Check for existing session ID const sessionId = req.headers['mcp-session-id']; const session = sessionId ? sessions.get(sessionId) : undefined; let transport; if (session) { // Reuse existing transport transport = session.transport; trackResponse(session, res); } else if (!sessionId && (0, types_js_1.isInitializeRequest)(req.body)) { // New initialization request - use JSON response mode if (sessions.size >= MAX_SESSIONS) { res.status(503).json({ jsonrpc: '2.0', error: { code: -32000, message: 'Too many open sessions' }, id: null }); return; } transport = new streamableHttp_js_1.StreamableHTTPServerTransport({ sessionIdGenerator: () => (0, node_crypto_1.randomUUID)(), enableJsonResponse: true, // Enable JSON response mode onsessioninitialized: sessionId => { // Store the transport by session ID when session is initialized // This avoids race conditions where requests might come in before the session is stored console.log(`Session initialized with ID: ${sessionId}`); sessions.set(sessionId, { transport, open: 0, lastActive: Date.now() }); } }); // Set up onclose handler to clean up transport when closed transport.onclose = () => { const sid = transport.sessionId; if (sid && sessions.has(sid)) { console.log(`Transport closed for session ${sid}, removing from sessions map`); sessions.delete(sid); } }; // Connect the transport to the MCP server BEFORE handling the request const server = getServer(); await server.connect(transport); await transport.handleRequest(req, res, req.body); return; // Already handled } else if (sessionId) { // Unknown or expired session ID - the client should start a new session res.status(404).json({ jsonrpc: '2.0', error: { code: -32001, message: 'Session not found' }, id: null }); return; } else { // Invalid request - no session ID and not an initialization request res.status(400).json({ jsonrpc: '2.0', error: { code: -32000, message: 'Bad Request: No valid session ID provided' }, id: null }); return; } // Handle the request with existing transport - no need to reconnect await transport.handleRequest(req, res, req.body); } catch (error) { console.error('Error handling MCP request:', error); if (!res.headersSent) { res.status(500).json({ jsonrpc: '2.0', error: { code: -32603, message: 'Internal server error' }, id: null }); } } }); // Handle GET requests for SSE streams according to spec app.get('/mcp', async (req, res) => { // Since this is a very simple example, we don't support GET requests for this server // The spec requires returning 405 Method Not Allowed in this case res.status(405).set('Allow', 'POST').send('Method Not Allowed'); }); // Start the server const PORT = 3000; app.listen(PORT, error => { if (error) { console.error('Failed to start server:', error); process.exit(1); } console.log(`MCP Streamable HTTP Server listening on port ${PORT}`); }); // Handle server shutdown process.on('SIGINT', async () => { console.log('Shutting down server...'); process.exit(0); }); //# sourceMappingURL=jsonResponseStreamableHttp.js.map