How do you structure an Express router module?

Import Express, create a Router, attach your route handlers to it, and export it for the main app to mount.

// users.js
import express from 'express';
const router = express.Router();

// Define route handlers
router.get('/', function(req, res) {
    res.send('List all users');
});

router.get('/:id', function(req, res) {
    res.send('Get user ' + req.params.id);
});

router.post('/', function(req, res) {
    res.send('Create user');
});

// Export the router
export default router;

In main app:

import usersRouter from './users.js';
app.use('/users', usersRouter);

Result:

• GET /users → List all users
• GET /users/123 → Get user 123
• POST /users → Create user

Tip: The URL prefix (/users) is set when mounting the router, not in the router itself.