Node.js API Tutorial

Creating APIs using Node.js is one of the most common tasks for backend developers. In this tutorial, you'll learn how to build a basic RESTful API using Node.js, Express.js, and MongoDB. This guide is beginner-friendly and ideal for those starting their journey into backend development.

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📚 What You'll Learn

• Setting up a Node.js project
• Creating a basic Express server
• Connecting MongoDB with Mongoose
• Creating RESTful routes (GET, POST, PUT, DELETE)
• Testing your API with Postman

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🔧 Prerequisites

Make sure you have the following installed:

• Node.js
• MongoDB (or use MongoDB Atlas)
• Postman (for testing API)

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1️⃣ Initialize Your Project

bash
1mkdir node-api-tutorial
2cd node-api-tutorial
3npm init -y
4``
5
6Then install dependencies:
7
8```bash
9npm install express mongoose dotenv

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2️⃣ Create Folder Structure

bash
1node-api-tutorial/
2├── controllers/
3├── models/
4├── routes/
5├── .env
6├── server.js

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3️⃣ Setup Basic Server (server.js)

js
1const express = require('express');
2const mongoose = require('mongoose');
3require('dotenv').config();
4
5const app = express();
6app.use(express.json());
7
8const PORT = process.env.PORT || 5000;
9
10// DB Connection
11mongoose.connect(process.env.MONGO_URI, {
12  useNewUrlParser: true,
13  useUnifiedTopology: true
14}).then(() => console.log("MongoDB Connected"))
15  .catch(err => console.error(err));
16
17// Routes
18const postRoutes = require('./routes/postRoutes');
19app.use('/api/posts', postRoutes);
20
21// Start Server
22app.listen(PORT, () => console.log(`Server running on port ${PORT}`));

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4️⃣ Create Post Model (models/Post.js)

js
1const mongoose = require('mongoose');
2
3const postSchema = new mongoose.Schema({
4  title: { type: String, required: true },
5  content: String
6}, { timestamps: true });
7
8module.exports = mongoose.model('Post', postSchema);

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5️⃣ Create Controller Functions (controllers/postController.js)

js
1const Post = require('../models/Post');
2
3exports.getAllPosts = async (req, res) => {
4  const posts = await Post.find();
5  res.json(posts);
6};
7
8exports.createPost = async (req, res) => {
9  const post = new Post(req.body);
10  await post.save();
11  res.status(201).json(post);
12};
13
14exports.getPost = async (req, res) => {
15  const post = await Post.findById(req.params.id);
16  res.json(post);
17};
18
19exports.updatePost = async (req, res) => {
20  const updatedPost = await Post.findByIdAndUpdate(req.params.id, req.body, { new: true });
21  res.json(updatedPost);
22};
23
24exports.deletePost = async (req, res) => {
25  await Post.findByIdAndDelete(req.params.id);
26  res.json({ message: 'Post deleted' });
27};

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6️⃣ Setup Routes (routes/postRoutes.js)

js
1const express = require('express');
2const router = express.Router();
3const postController = require('../controllers/postController');
4
5router.get('/', postController.getAllPosts);
6router.post('/', postController.createPost);
7router.get('/:id', postController.getPost);
8router.put('/:id', postController.updatePost);
9router.delete('/:id', postController.deletePost);
10
11module.exports = router;

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7️⃣ Setup Environment File (.env)

env
1PORT=5000
2MONGO_URI=mongodb://localhost:27017/node_api

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🧪 Test Your API

Open Postman and test the following endpoints:

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✅ Bonus Tips

• Use nodemon for auto-restart during development: npm install --save-dev nodemon
• Structure code using MVC pattern (Model, View, Controller)
• Add validation using express-validator
• Secure the API using JWT for authentication

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📚 Free Resources to Learn More

• Node.js Crash Course (Traversy Media)
• MongoDB University Free Courses
• Postman Learning Center

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Happy Coding! ⚡