Advanced MCP Features

#!/usr/bin/env node import { createServer } from 'http' import { randomBytes } from 'node:crypto' import { styleText } from 'node:util' import { execa } from 'execa' import getPort from 'get-port' import httpProxy from 'http-proxy' const { createProxyServer } = httpProxy const [, , ...args] = process.argv const [transport] = args const serverPort = await getPort({ port: Array.from({ length: 1000 }, (_, i) => i + 10000), exclude: [process.env.PORT].filter(Boolean).map(Number), }) const clientPort = await getPort({ port: Array.from({ length: 1000 }, (_, i) => i + 9000), exclude: [process.env.PORT, serverPort].filter(Boolean).map(Number), }) const sessionToken = randomBytes(32).toString('hex') // Spawn mcp-inspector as a sidecar process const inspectorProcess = execa('mcp-inspector', [], { env: { ...process.env, SERVER_PORT: serverPort, CLIENT_PORT: clientPort, MCP_PROXY_AUTH_TOKEN: sessionToken, MCP_AUTO_OPEN_ENABLED: 'false', ALLOWED_ORIGINS: [ `http://localhost:${clientPort}`, `http://127.0.0.1:${clientPort}`, `http://localhost:${process.env.PORT}`, `http://127.0.0.1:${process.env.PORT}`, ].join(','), }, stdio: ['inherit', 'pipe', 'inherit'], // capture stdout }) /* Starting MCP inspector... ⚙️ Proxy server listening on localhost:10039 🔑 Session token: 27d8e2e73dfdc8051ba0c1cc38e07a0623680184167543ccfd33c61f2d3819b3 Use this token to authenticate requests or set DANGEROUSLY_OMIT_AUTH=true to disable auth 🚀 MCP Inspector is up and running at: http://localhost:9038/?MCP_PROXY_PORT=10039&MCP_PROXY_AUTH_TOKEN=27d8e2e73dfdc8051ba0c1cc38e07a0623680184167543ccfd33c61f2d3819b3 */ // Wait for the inspector to be up before starting the proxy server function waitForInspectorReady() { return new Promise((resolve) => { inspectorProcess.stdout.on('data', (data) => { const str = data.toString() if (str.includes(clientPort)) resolve() // Suppress specific logs from inspector if ( /server listening/i.test(str) || /inspector is up/i.test(str) || /session token/i.test(str) || /DANGEROUSLY_OMIT_AUTH/i.test(str) || /up and running/i.test(str) || /localhost/i.test(str) || /auto-open is disabled/i.test(str) ) { return } process.stdout.write(str) // print all other inspector logs }) }) } await waitForInspectorReady() const proxy = createProxyServer({ target: `http://localhost:${clientPort}`, ws: true, changeOrigin: true, }) const server = createServer((req, res) => { if (req.url === '/' || req.url.startsWith('/?')) { const url = new URL(req.url, `http://localhost:${clientPort}`) const transport = 'stdio' const command = 'npm' const args = `--silent --prefix "${process.cwd()}" run dev:mcp` url.searchParams.set('transport', transport) url.searchParams.set('serverCommand', command) url.searchParams.set('serverArgs', args) url.searchParams.set('MCP_PROXY_AUTH_TOKEN', sessionToken) url.searchParams.set( 'MCP_PROXY_FULL_ADDRESS', `http://localhost:${serverPort}`, ) url.searchParams.set('MCP_REQUEST_MAX_TOTAL_TIMEOUT', 1000 * 60 * 15) url.searchParams.set('MCP_SERVER_REQUEST_TIMEOUT', 1000 * 60 * 5) const correctedUrl = url.pathname + url.search if (correctedUrl !== req.url) { res.writeHead(302, { Location: correctedUrl }) res.end() return } } proxy.web(req, res, {}, (err) => { res.writeHead(502, { 'Content-Type': 'text/plain' }) res.end('Proxy error: ' + err.message) }) }) server.on('upgrade', (req, socket, head) => { proxy.ws(req, socket, head) }) server.listen(process.env.PORT, () => { // Enhanced, colorized logs const proxyUrl = `http://localhost:${process.env.PORT}` console.log( styleText('cyan', `🐨 Proxy server running: `) + styleText('green', proxyUrl), ) console.log( styleText('gray', `- Client port: `) + styleText('magenta', clientPort.toString()), ) console.log( styleText('gray', `- Server port: `) + styleText('yellow', serverPort.toString()), ) }) // Ensure proper cleanup function cleanup() { if (inspectorProcess && !inspectorProcess.killed) { inspectorProcess.kill() } proxy.close() server.close(() => { console.log('HTTP server closed') }) } process.on('exit', cleanup) process.on('SIGINT', () => { cleanup() process.exit(0) }) process.on('SIGTERM', () => { cleanup() process.exit(0) })