Fastify is a web server framework for Node.js that is an alternative to Express.

Benefits include:

• one of the fastest Node-based web servers
• supports JSON Schema for validating requests
• uses Pino for logging
• maintains a TypeScript type declaration file so usage can be type checked
• provides a good developer experience

To install Fastify in a project, enter npm install fastify.

To enable serving static files, enter npm install fastify-static.

To enable accessing environment-specific environment files, enter npm install dotenv. Then create a .env file that defines environment variables with lines like MONGO_URL=some-url. A different version of this file can be created for each environment, such as dev, test, stage, and production.

To run the server in watch mode, install nodemon by entering npm install -g nodemon. Then run the app using the nodemon command instead of node.

To use ECMAScript Modules (ESM), edit package.json and add the line "type": "module",. This enables using the following syntax to import a JavaScript file from another one:

import './some-name.js'; // file extension is required

Set MONGO_URL to mongodb+srv://{username}:{password}@cluster0.3efbd.mongodb.net/myFirstDatabase?retryWrites=true&w=majority

Here is code for an example server.

import dotenv from 'dotenv';
import {fastify} from 'fastify';
import fastifyStatic from 'fastify-static';
import path from 'path';
import {fileURLToPath} from 'url';

// Normally these names are defined by Node.js.
// But when "type" is set to "module" in package.json,
// these go away.
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const PORT = 1919;

// Load environment variables from the .env file into process.env.
// For example, process.env.MONGO_URL.
dotenv.config();

const app = fastify();

async function startApp() {
  try {
    // Serve static files from the "public" directory.
    app.register(fastifyStatic, {
      root: path.join(__dirname, 'public')
    });

    // Define "/" route.
    app.get('/', {}, (request, reply) => {
      reply.send({foo: 'bar'}); // sets Content-Type to application/json
    });

    await app.listen(PORT);
    console.log('listening on port', PORT);
  } catch (e) {
    console.error(e);
  }
}

startApp();