TypeScript MCP server

1/**
2 * ArXiv MCP Server - Main Entry Point
3 *
4 * This file serves as the entry point for the ArXiv MCP Server Actor.
5 * It sets up a proxy server that forwards requests to the locally running
6 * ArXiv MCP server, which provides a Model Context Protocol (MCP) interface
7 * for AI assistants to search and access arXiv papers.
8 */
9
10// Apify SDK - toolkit for building Apify Actors (Read more at https://docs.apify.com/sdk/js/)
11import { Actor, log } from 'apify';
12import { stdioToSse } from './lib/server.js';
13import { getLogger } from './lib/getLogger.js';
14
15// This is an ESM project, and as such, it requires you to specify extensions in your relative imports
16// Read more about this here: https://nodejs.org/docs/latest-v18.x/api/esm.html#mandatory-file-extensions
17// Note that we need to use `.js` even when inside TS files
18// import { router } from './routes.js';
19
20// Configuration constants for the MCP server
21// Command to run the ArXiv MCP server using uv package manager
22// TODO: Do not forget to install the MCP server in the Dockerfile
23const MCP_COMMAND = 'uv tool run arxiv-mcp-server';
24
25// Check if the Actor is running in standby mode
26const STANDBY_MODE = process.env.APIFY_META_ORIGIN === 'STANDBY';
27const SERVER_PORT = parseInt(process.env.ACTOR_WEB_SERVER_PORT || '', 10);
28
29// Logger configuration
30const LOG_LEVEL = 'info';
31const OUTPUT_TRANSPORT = 'sse';
32
33// Initialize the Apify Actor environment
34// The init() call configures the Actor for its environment. It's recommended to start every Actor with an init()
35await Actor.init();
36
37// Charge for Actor start
38await Actor.charge({ eventName: 'actor-start' });
39
40if (!STANDBY_MODE) {
41    // If the Actor is not in standby mode, we should not run the MCP server
42    const msg = 'This Actor is not meant to be run directly. It should be run in standby mode.';
43    log.error(msg);
44    await Actor.exit({ statusMessage: msg });
45}
46
47const logger = getLogger({
48    logLevel: LOG_LEVEL,
49    outputTransport: OUTPUT_TRANSPORT,
50});
51await stdioToSse({
52    port: SERVER_PORT,
53    stdioCmd: MCP_COMMAND,
54    logger,
55});