SnowLuma/.pnpm-store/v11/files/73/759dd97909882b4b4044ed66c1a38b29b849ac7aea38527cfcccf4ac8fd79a36ceb884c799637756aa61100dc932f8eaf7bb0d16564947250521f4c9517f8b

import { randomUUID } from 'node:crypto';
import { McpServer } from '../../server/mcp.js';
import { StreamableHTTPServerTransport } from '../../server/streamableHttp.js';
import * as z from 'zod/v4';
import { isInitializeRequest } from '../../types.js';
import { createMcpExpressApp } from '../../server/express.js';
// Create an MCP server with implementation details
const getServer = () => {
    const server = new 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 = 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 && 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 StreamableHTTPServerTransport({
                sessionIdGenerator: () => 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);
});
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