How to Build Your First REST API: Best Practices for New Developers

APIs (Application Programming Interfaces) power almost everything we use online today — from logging into apps with Google to fetching live weather data. Among them, REST APIs are the most popular choice because they are simple, scalable, and widely supported.

If you’re a new developer in the USA or UK, learning to build a REST API is one of the most valuable skills you can add to your toolkit. Not only does it improve your backend development knowledge, but it also makes you more employable in the tech industry.

In this article, we’ll walk you through how to build your first REST API, covering tools, setup, and best practices every new developer should know.

What is a REST API?

REST stands for Representational State Transfer, a standard architecture for building APIs. A REST API allows communication between a client (like a web app) and a server using HTTP methods such as:

• GET → Retrieve data.
• POST → Add new data.
• PUT/PATCH → Update existing data.
• DELETE → Remove data.

Example:
A GET request to https://api.example.com/users might return a list of users in JSON format.
If you’re new to coding, check our Beginner’s Guide to HTML Basics to strengthen your foundation.

Tools You’ll Need

Before building your first REST API, make sure you have these installed:

• Node.js & npm → Backend runtime & package manager.
• Express.js → Framework to simplify API creation.
• Postman or Thunder Client → Tools for testing APIs.
• VS Code → Recommended code editor.

Download Node.js from nodejs.org.

Step-by-Step Guide: Building Your First REST API

Let’s build a simple API for managing users.

Step 1: Initialize Your Project

Open your terminal and create a new folder:
bash

mkdir user-api
cd user-api
npm init -y
This sets up your project with a package.json file.

Step 2: Install Dependencies

Install Express.js:
bash

npm install express< /code>

Step 3: Create the Server

Create a file server.js:
javascript

const express = require('express');
const app = express();
const PORT = 5000;

app.use(express.json());

app.listen(PORT, () => {
console.log(`Server running on http://localhost:${PORT}`);
});

Run with:
bash

node server.js
You should see: Server running on http://localhost:5000.

Step 4: Add Routes

Add routes for CRUD operations:
javascript

let users = [
{ id: 1, name: "Alice" },
{ id: 2, name: "Bob" }
];

// GET all users
app.get('/users', (req, res) => {
res.json(users);
});

// POST new user
app.post('/users', (req, res) => {
const newUser = { id: users.length + 1, name: req.body.name };
users.push(newUser);
res.status(201).json(newUser);
});

// PUT update user
app.put('/users/:id', (req, res) => {
const id = parseInt(req.params.id);
const user = users.find(u => u.id === id);
if (user) {
user.name = req.body.name;
res.json(user);
} else {
res.status(404).json({ message: "User not found" });
}
});

// DELETE user
app.delete('/users/:id', (req, res) => {
users = users.filter(u => u.id !== parseInt(req.params.id));
res.json({ message: "User deleted" });
});

Step 5: Test with Postman

• GET → http://localhost:5000/users → Returns all users.
• POST → Add { “name”: “Charlie” }.
• PUT → Update a user’s name.
• DELETE → Remove a user by ID.

Congrats you just built your first REST API!
Once you’re comfortable with APIs, explore Top 15 Git Commands Every Developer Should Know.

Best Practices for New Developers

Building an API is just the start — writing scalable and secure APIs is the real goal.

1. Use Proper HTTP Status Codes

Always return meaningful responses:

• 200 OK → Success
• 201 Created → Resource added
• 400 Bad Request → Invalid input
• 404 Not Found → Resource doesn’t exist

2. Validate Input Data

Never trust client data. Use libraries like Joi or Express Validator to sanitize and validate input.
javascript

if (!req.body.name) {
return res.status(400).json({ error: "Name is required" });
}

3. Secure Your API

• Use HTTPS.
• Implement authentication (JWT, OAuth2).
• Limit requests with rate limiting.

For security basics, read Best Chrome Extensions for Web Developers.

4. Use Environment Variables

Never hardcode sensitive data like API keys. Use .env files with dotenv.

5. Version Your API

Keep your API future-proof by versioning:
/api/v1/users instead of /users.

6. Add Documentation

Use tools like Swagger or Postman Collections to document endpoints clearly.

Learn more at Swagger.io.

7. Handle Errors Gracefully

Always provide useful error messages without exposing sensitive server details.

8. Test Your API

Use Jest, Mocha, or Supertest for automated testing.

9. Optimize for Performance

• Use caching (Redis).
• Minimize database queries.
• Use pagination for large datasets.

10. Deploy Your API

Host your API on platforms like Heroku, Vercel, or AWS for public access.
Once deployed, you can integrate it into a project like How to Create a Portfolio Website with WordPress.

Common Mistakes to Avoid

• Ignoring error handling.
• Not using HTTPS.
• Overloading responses with unnecessary data.
• Forgetting API documentation.
• Hardcoding credentials.

FAQs – REST API for Beginners

Q1: What is the difference between REST API and GraphQL?
REST uses multiple endpoints; GraphQL allows flexible queries in one endpoint.

Q2: Do I need to know backend programming to build APIs?
Yes, at least basics of Node.js, Python, or PHP are necessary.

Q3: Can I build a REST API with Python instead of Node.js?
Absolutely! Python frameworks like Flask and Django REST Framework are excellent alternatives.

Q4: How long does it take to learn REST APIs?
Most beginners can build simple APIs in 2–4 weeks of practice.

Q5: Is REST API still relevant in 2025?
Yes! While GraphQL is growing, REST remains the most widely used standard.

Wrapping Up

You’ve just learned how to build your first REST API with Node.js and Express, along with the best practices to make it secure, scalable, and efficient.

Here’s a quick recap:

• Understand REST principles.
• Set up a Node.js + Express server.
• Create CRUD endpoints.
• Test using Postman.
• Follow best practices: security, validation, versioning, documentation.

Ready to dive deeper? Explore Node.js vs PHP: Which is Better for Beginners?.
Explore the MDN Guide on REST APIs for further reading.