Lorem Ipsum MCP Server

#!/usr/bin/env node import { Client } from "@modelcontextprotocol/sdk/client/index.js"; import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { EventSource } from "eventsource"; import { setTimeout } from "node:timers"; import util from "node:util"; import yargs from "yargs"; import { hideBin } from "yargs/helpers"; import { InMemoryEventStore } from "../InMemoryEventStore.js"; import { proxyServer } from "../proxyServer.js"; import { startHTTPStreamServer } from "../startHTTPStreamServer.js"; import { startSSEServer } from "../startSSEServer.js"; import { StdioClientTransport } from "../StdioClientTransport.js"; util.inspect.defaultOptions.depth = 8; if (!("EventSource" in global)) { // @ts-expect-error - figure out how to use --experimental-eventsource with vitest global.EventSource = EventSource; } const argv = await yargs(hideBin(process.argv)) .scriptName("mcp-proxy") .command("$0 <command> [args...]", "Run a command with MCP arguments") .positional("command", { demandOption: true, describe: "The command to run", type: "string", }) .positional("args", { array: true, describe: "The arguments to pass to the command", type: "string", }) .env("MCP_PROXY") .options({ debug: { default: false, describe: "Enable debug logging", type: "boolean", }, endpoint: { describe: "The endpoint to listen on", type: "string", }, port: { default: 8080, describe: "The port to listen on", type: "number", }, server: { choices: ["sse", "stream"], default: "sse", describe: "The server type to use (sse or stream)", type: "string", }, }) .help() .parseAsync(); const connect = async (client: Client) => { const transport = new StdioClientTransport({ args: argv.args, command: argv.command, env: process.env as Record<string, string>, onEvent: (event) => { if (argv.debug) { console.debug("transport event", event); } }, stderr: "pipe", }); await client.connect(transport); }; const proxy = async () => { const client = new Client( { name: "mcp-proxy", version: "1.0.0", }, { capabilities: {}, }, ); await connect(client); const serverVersion = client.getServerVersion() as { name: string; version: string; }; const serverCapabilities = client.getServerCapabilities() as { capabilities: Record<string, unknown>; }; console.info("starting the %s server on port %d", argv.server, argv.port); const createServer = async () => { const server = new Server(serverVersion, { capabilities: serverCapabilities, }); proxyServer({ client, server, serverCapabilities, }); return server; }; if (argv.server === "sse") { await startSSEServer({ createServer, endpoint: argv.endpoint || ("/sse" as `/${string}`), port: argv.port, }); } else { await startHTTPStreamServer({ createServer, endpoint: argv.endpoint || ("/stream" as `/${string}`), eventStore: new InMemoryEventStore(), port: argv.port, }); } }; const main = async () => { process.on("SIGINT", () => { console.info("SIGINT received, shutting down"); setTimeout(() => { process.exit(0); }, 1000); }); try { await proxy(); } catch (error) { console.error("could not start the proxy", error); setTimeout(() => { process.exit(1); }, 1000); } }; await main();