Node.jsDébutant 6 min·Updated: 2026-09-07

Build a RESTful API with Node.js and Express (Production Architecture)

Learn to build scalable, production-ready REST APIs using the classic Node.js Express framework.

Concepts & Theory

Express provides lightweight routing abstractions for HTTP verbs (GET, POST, PUT, DELETE) and JSON serialization.

Middlewares compose pipeline interceptors for authentication, request parsing, and rate limiting.

Using standard HTTP response status codes (200, 201, 400, 404, 500) ensures seamless API consumer integration.

Code Example

Run in Playground

JAVASCRIPTPROJET CARTHAGE

const express = require('express');
const app = express();
const PORT = process.env.PORT || 3000;

// Middleware pour parser les corps JSON
app.use(express.json());

// Base de données simulée en mémoire
let exercices = [
  { id: 1, titre: "Boucles Python", langage: "python" },
  { id: 2, titre: "Promesses JS", langage: "javascript" }
];

// GET /api/exercices - Liste complète
app.get('/api/exercices', (req, res) => {
  res.json({ success: true, count: exercices.length, data: exercices });
});

// POST /api/exercices - Création
app.post('/api/exercices', (req, res) => {
  const { titre, langage } = req.body;
  if (!titre || !langage) {
    return res.status(400).json({ error: "Le titre et le langage sont obligatoires." });
  }

  const nouvelExercice = { id: Date.now(), titre, langage };
  exercices.push(nouvelExercice);
  res.status(201).json({ success: true, data: nouvelExercice });
});

app.listen(PORT, () => {
  console.log(`Serveur API Carthage en écoute sur http://localhost:${PORT}`);
});

Common Pitfalls & Mistakes

✗ Omitting express.json() middleware

Incorrect / Error

app.post("/api", (req, res) => {
  console.log(req.body); // undefined
});

Idiomatic / Correct

app.use(express.json());

Without the body parser middleware, `req.body` remains undefined on incoming JSON POST requests.

Frequently Asked Questions

What is the difference between PUT and PATCH in a REST API?▾

PUT replaces the entire entity representation, whereas PATCH performs partial field modifications.

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Concepts & Theory

Express provides lightweight routing abstractions for HTTP verbs (GET, POST, PUT, DELETE) and JSON serialization.

Middlewares compose pipeline interceptors for authentication, request parsing, and rate limiting.

Using standard HTTP response status codes (200, 201, 400, 404, 500) ensures seamless API consumer integration.