Create a Node.js server for app hosting

A Node.js deployment rarely fails because of the language: it fails because the main file cannot be found, a dependency is missing or the server listens on an unreachable address. Start from a minimal server with no dependencies, confirm it runs locally, then add your logic. You will then be able to tell a platform problem from a code problem.

Minimal structure

Two files are enough: the entry point and the manifest.

my-app/
  index.js
  package.json

The HTTP server

The code below uses only the standard library. It reads the port from the environment, listens on every interface and exposes a health route.

const http = require("node:http");

const port = Number(process.env.PORT) || 3000;

const server = http.createServer((req, res) => {
  if (req.url === "/health") {
    res.writeHead(200, { "content-type": "application/json" });
    res.end(JSON.stringify({ status: "ok" }));
    return;
  }
  res.writeHead(200, { "content-type": "text/plain; charset=utf-8" });
  res.end("Hello from Node.js\n");
});

server.listen(port, "0.0.0.0", () => {
  console.log(`listening on ${port}`);
});

process.on("SIGTERM", () => server.close(() => process.exit(0)));

0.0.0.0 is essential: with 127.0.0.1 the server accepts only local connections and stays unreachable from outside. The 3000 fallback is for local development only; on the platform, PORT is provided.

The package.json

{
  "name": "my-app",
  "version": "1.0.0",
  "private": true,
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "engines": {
    "node": ">=20"
  }
}

main and the start script must point to the real file. If you rename index.js to server.js, update all three: the file name, main and the start command.

Deploy

1. Upload the files or clone the repository into the service.
2. Run npm install if a package.json declares dependencies.
3. Confirm the start command is node index.js (or npm start).
4. Start, then read the console: the listening on ... line must appear.
5. Call /health from outside to confirm the port is exposed.

Do not upload node_modules: the platform installs declared dependencies. However, always commit package-lock.json for reproducible installs.

Common errors

A minimal server that answers on /health is the best diagnostic base: as long as it works, the problem is in your code, not the platform.