Build HTTP APIs with routing, middleware, validation, controllers, and error handling.
Lessons
Keep core Express APIs and patterns at your fingertips.
Express Cheatsheet is easiest to learn by reading the example, changing it, and observing the result.
import express from 'express';
const app = express();
app.use(express.json());
app.get('/api/lessons', (req, res) => {
res.json([{ slug: 'express-routing', title: 'Express Routing' }]);
});
app.post('/api/lessons', (req, res) => {
res.status(201).json({ created: true, title: req.body.title });
});
app.listen(process.env.PORT || 3000);Practice the Express Cheatsheet example in a small scratch file, then explain what changed and why.