Tag: programming

Build Your First REST API with Node.js

REST APIs are the backbone of modern web and mobile applications. If you’re learning backend development, building a REST API using Node.js is one of the best places to start.

In this guide, you’ll learn how to build your first REST API in Node.js using Express.js, with simple examples you can run locally.

Prerequisites

Before starting, make sure you have:

  • Basic JavaScript knowledge
  • Node.js installed
  • A code editor (VS Code recommended)

Check Node.js installation:

node -v
npm -v

What Is a REST API?

A REST API allows applications to communicate with each other using HTTP methods:

  • GET – Fetch data
  • POST – Create data
  • PUT – Update data
  • DELETE – Remove data

REST APIs usually return data in JSON format.

Step 1: Create a New Node.js Project

Create a folder and initialize your project:

mkdir my-first-api
cd my-first-api
npm init -y

This creates a package.json file.

Step 2: Install Required Packages

We’ll use Express.js, a popular Node.js framework.

npm install express

Optional (for auto restart):

npm install nodemon --save-dev

Step 3: Create the Server File

Create a file named index.js:

const express = require('express');
const app = express();

app.use(express.json());

const PORT = 3000;

app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

Run the server:

node index.js

Visit 👉 http://localhost:3000

Step 4: Create Your First API Route

Add a GET API:

app.get('/', (req, res) => {
  res.json({ message: 'Welcome to my first REST API!' });
});

Now open the browser:

http://localhost:3000/

You’ll see JSON output

Step 5: Create a GET API (Fetch Data)

Let’s return a list of users:

app.get('/users', (req, res) => {
  const users = [
    { id: 1, name: 'John' },
    { id: 2, name: 'Sara' }
  ];
  res.json(users);
});

URL:

GET /users

Step 6: Create a POST API (Add Data)

app.post('/users', (req, res) => {
  const user = req.body;
  res.status(201).json({
    message: 'User created',
    user
  });
});

Test using Postman or Thunder Client:

POST /users
{
  "name": "Alex"
}

Step 7: Create PUT API (Update Data)

app.put('/users/:id', (req, res) => {
  res.json({
    message: `User ${req.params.id} updated`
  });
});

Step 8: Create DELETE API

app.delete('/users/:id', (req, res) => {
  res.json({
    message: `User ${req.params.id} deleted`
  });
});

Step 9: Test Your API

You can test APIs using:

  • Postman
  • Thunder Client (VS Code extension)
  • curl command

Suggested Project Structure (Beginner)

my-first-api
│
|--- index.js
|--- package.json
|--- node_modules

As your app grows, you can separate routes, controllers, and services.

Best Practices for Node.js REST APIs

  • Use environment variables
  • Validate input
  • Use async/await
  • Add logging

Frequently Asked Questions

Is Node.js good for REST APIs?

Yes, Node.js is widely used…

Which framework is best for Node.js REST API?

Express.js is the most popular…

Can beginners learn REST API in Node.js?

Absolutely…