Apply ⏱ 12 min

RESTful APIs in 100 Seconds // Build an API from Scratch with Node.js Express

What You Will Learn

How to build a RESTful API from scratch using Node.js and Express.js
How to create different endpoints for your API, including GET and POST requests
How to use middleware to parse JSON data in your API requests

Key Concepts

RESTful APIs are a way for two computers to talk to each other using a standardized set of rules. They organize data entities or resources into unique URLs, and clients can get data about a resource by making a request to that endpoint over HTTP. The request message has a specific format, including an HTTP verb, headers, and a body. The server responds with a status code, headers, and a response body, usually in JSON format. Another key concept is that RESTful APIs are stateless, meaning that the two parties don’t need to store any information about each other, and every request-response cycle is independent.

Code Examples

app.get('/t-shirt', (req, res) => {
  // Send a response back to the client
  res.json({ message: 'Hello World' });
})
// This code sets up a GET endpoint for the /t-shirt URL and sends a JSON response back to the client.

const express = require('express');
const app = express();
app.use(express.json());
// This code sets up an Express.js app and uses middleware to parse JSON data in the request body.

app.post('/t-shirt/:id', (req, res) => {
  const { id } = req.params;
  const { logo } = req.body;
  // This code handles a POST request to the /t-shirt/:id endpoint and extracts the ID and logo from the request parameters and body.

Lesson Summary

In this lesson, we learned how to build a RESTful API from scratch using Node.js and Express.js. We started by understanding what RESTful APIs are and how they work, including the different parts of a request and response message. We then moved on to building our own API, starting with a simple GET endpoint and then adding a POST endpoint to create new data. We also learned about middleware and how to use it to parse JSON data in our API requests. Throughout the lesson, we used Express.js to create our API and Insomnia to test it. By the end of the lesson, we had a fully functional RESTful API that we could use to retrieve and create data.

Practice Exercise

Create a new endpoint for your API that handles a GET request to /users and returns a JSON response with a list of user names. Use Express.js to create the endpoint and Insomnia to test it.

What Is Next

In the next lesson, we will learn about more advanced concepts in building RESTful APIs, including how to secure and deploy our API to a cloud platform. We will also explore tools like API Gateway and SwaggerHub to help us manage and document our API.

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