The http Module

A minimal server

http.createServer takes a callback that runs for every incoming request.

import http from "node:http";

const server = http.createServer((req, res) => {
  res.writeHead(200, { "Content-Type": "text/plain" });
  res.end("Hello, Node server!");
});

server.listen(3000, () => {
  console.log("Listening on http://localhost:3000");
});

Output:

Listening on http://localhost:3000

Routing manually

Without a framework, you branch on req.method and req.url yourself.

const server = http.createServer((req, res) => {
  if (req.method === "GET" && req.url === "/") {
    res.end("Home page");
  } else if (req.method === "GET" && req.url === "/about") {
    res.end("About page");
  } else {
    res.writeHead(404);
    res.end("Not found");
  }
});

Frameworks exist for a reason

Manual routing gets messy fast — frameworks like Express layer clean routing, middleware, and parsing on top of this same http module.

Quick check: What does res.end() do?

• Starts the server
• Sends the response and closes it
• Deletes the request