MCP Server Starter

import { createServer } from "node:net"; import { setTimeout } from "node:timers/promises"; /** * Find an available port on the system */ export async function getAvailablePort(): Promise<number> { return new Promise((resolve, reject) => { const server = createServer(); server.listen(0, () => { const address = server.address(); if (address !== null && typeof address !== "string") { const port = address.port; server.close(() => { resolve(port); }); } else { server.close(); reject(new Error("Failed to get port from server")); } }); server.on("error", (err) => { reject(err); }); }); } /** * Wait for a port to become available (server is listening) */ export async function waitForPort( port: number, host = "localhost", options: { timeout?: number; interval?: number } = {} ): Promise<void> { const { timeout = 10000, interval = 100 } = options; const startTime = Date.now(); while (Date.now() - startTime < timeout) { try { await new Promise<void>((resolve, reject) => { const socket = createServer().listen(port, host); socket.on("error", (err: NodeJS.ErrnoException) => { if (err.code === "EADDRINUSE") { // Port is in use, which means server is ready resolve(); } else { reject(err); } }); socket.on("listening", () => { // Port was free, server not ready yet socket.close(() => { reject(new Error("Port not in use")); }); }); }); // If we get here, port is in use (server is ready) return; } catch { // Port not ready yet, wait and retry await setTimeout(interval); } } throw new Error(`Timeout waiting for port ${String(port)} to be ready`); } /** * Check if a port is available */ export async function isPortAvailable(port: number, host = "localhost"): Promise<boolean> { return new Promise((resolve) => { const server = createServer(); server.listen(port, host, () => { server.close(() => { resolve(true); }); }); server.on("error", (err: NodeJS.ErrnoException) => { if (err.code === "EADDRINUSE") { resolve(false); } else { resolve(true); } }); }); }