Building REST APIs with Node.js

# Building REST APIs with Node.js A REST API exposes data and actions over HTTP using standard methods — GET, POST, PUT, DELETE — mapped to resources like `/students` or `/courses`. ## A Minimal Server ```javascript const http = require("http"); const server = http.createServer((req, res) => { if (req.url === "/courses" && req.method === "GET") { res.writeHead(200, { "Content-Type": "application/json" }); res.end(JSON.stringify([{ id: 1, name: "Full Stack" }])); } }); server.listen(3000); ``` Raw Node.js works but gets unwieldy fast, which is why frameworks like Express exist. ## Resource-Based Routes ``` GET /courses → list all courses GET /courses/:id → get one course POST /courses → create a course PUT /courses/:id → update a course DELETE /courses/:id → delete a course ``` Following this convention makes the API predictable for anyone consuming it. ## Status Codes Matter Returning `200` for everything, including errors, makes an API hard to consume. Use `201` for created resources, `400` for bad input, `404` for missing resources, and `500` for server errors. ## Request Validation Never trust incoming data. Validate request bodies before touching a database — a missing or malformed field should return a clear `400` error, not crash the server. ## Structuring a Real Project Separate routes, controllers (business logic), and data access into different layers. This keeps route files thin and makes logic testable independent of HTTP. ## Conclusion REST API design is mostly about consistency — predictable routes, correct status codes, and clear error responses matter more than clever code.