Getting ahead a bit, let's set up a very basic server, which will answer all the requests by sending back a 'Server alive!' string. For this, we will need to follow three steps:

1. Use require() to import the http module of Node—we'll see more on modules in the next section; for the time being, just assume that require() is equivalent to import.
2. Then, use the createServer() method to set up our server.
3. After that, provide a function that will answer all requests by sending back a text/plain fixed answer.

The following code represents the most basic possible server, and will let us know whether everything has worked correctly. I have named the file miniserver.js. The line in bold does all the work, which we'll go over in the next section:

// Source file: src/miniserver.js

/* @flow */
"use strict";

const http = require("http");

http
    .createServer((req, res) => {
        res.writeHead(200, { "Content-Type": "text/plain" });
        res.end("Server alive!");
    })
    .listen(8080, "localhost");

console.log("Mini server ready at http://localhost:8080/");