The built-in http module creates servers and makes HTTP requests without external dependencies.

Creating a Server 

  import http from 'http';

const server = http.createServer((req, res) => {
    const { method, url } = req;

    if (method === 'GET' && url === '/') {
        res.writeHead(200, { 'Content-Type': 'text/plain' });
        res.end('Welcome!');
    } else if (method === 'GET' && url === '/api/users') {
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify([{ id: 1, name: 'Alice' }]));
    } else {
        res.writeHead(404, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'Not Found' }));
    }
});

server.listen(3000, () => console.log('Server on port 3000'));

Parsing Request Body 

  function parseBody(req) {
    return new Promise((resolve, reject) => {
        let body = '';
        req.on('data', chunk => body += chunk);
        req.on('end', () => {
            try {
                resolve(body ? JSON.parse(body) : {});
            } catch (err) {
                reject(err);
            }
        });
        req.on('error', reject);
    });
}

server.on('request', async (req, res) => {
    if (req.method === 'POST' && req.url === '/api/users') {
        try {
            const user = await parseBody(req);
            res.writeHead(201, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ id: Date.now(), ...user }));
        } catch {
            res.writeHead(400, { 'Content-Type': 'application/json' });
            res.end(JSON.stringify({ error: 'Invalid JSON' }));
        }
    }
});

Making HTTP Requests 

  import http from 'http';

const options = {
    hostname: 'api.example.com',
    port: 80,
    path: '/users/1',
    method: 'GET',
    headers: { 'Accept': 'application/json' }
};

const req = http.request(options, (res) => {
    let data = '';
    res.on('data', chunk => data += chunk);
    res.on('end', () => console.log(JSON.parse(data)));
});

req.on('error', (err) => console.error(err));
req.end();

Using fetch in Node.js (18+)

Node.js 18+ includes the global fetch API:

  const response = await fetch('https://api.example.com/users');
const users = await response.json();
console.log(users);

Status Codes Reference

Code Meaning
200 OK
201 Created
400 Bad Request
401 Unauthorized
404 Not Found
500 Internal Server Error

HTTPS 

  import https from 'https';
import fs from 'fs';

const options = {
    key: fs.readFileSync('key.pem'),
    cert: fs.readFileSync('cert.pem')
};

https.createServer(options, (req, res) => {
    res.end('Secure connection');
}).listen(443);

For production APIs, use Express (next chapter) instead of raw http — it simplifies routing, middleware, and error handling.