mini-express

A lightweight Express-compatible framework built from scratch with Node.js core modules.

Features

• app.listen(port, cb) over Node http
• Routing: get, post, put, patch, delete
• Middleware system with app.use(...) and next()
• Route-specific middleware (app.get('/admin', auth, handler))
• Dynamic route params (/users/:id/books/:bookId)
• Request helpers: req.params, req.query, req.body
• Response helpers: res.status, res.send, res.json, res.redirect
• Async handler support with automatic promise rejection forwarding
• Centralized error middleware
• Nested routers (mini.Router() + app.use('/prefix', router))
• Static file middleware (mini.static(dir))
• JSON body parser (mini.json())
• Next.js-like file-based API routing (app.useFileRoutes, mini.fileRoutes)
• Built-in 404 JSON response
• TypeScript declarations (index.d.ts)

Install

npm install

Quick start

const mini = require('./index');

const app = mini();

app.use(mini.json());

app.get('/', (req, res) => {
  res.send('Hello from Mini Express');
});

app.get('/users/:id', (req, res) => {
  res.json({ id: req.params.id });
});

app.listen(3000, () => {
  console.log('http://localhost:3000');
});

File-based API routes

examples/api/users/[id].js maps to GET /api/users/:id.

const path = require('node:path');
const mini = require('./index');

const app = mini();
app.useFileRoutes(path.join(__dirname, 'api'), { basePath: '/api' });

Supported conventions:

• index.js => directory root route
• [id].js => dynamic param :id
• [...slug]/index.js => catch-all param :slug*
• named exports: get, post, put, patch, delete

Scripts

• npm test - run unit tests
• npm run typecheck - verify TypeScript usage
• npm start - run examples/basic.js

Examples

• examples/basic.js
• examples/router.js
• examples/auth.js
• examples/rest-api.js
• examples/file-routes.js
• examples/typescript.ts

Notes

This project intentionally keeps implementation simple and readable while following good structure and naming conventions.