# Polka — Micro Web Server for Node.js

> Polka is a fast, minimal Node.js web server that provides Express-compatible routing in a package under 5 KB, making it suitable for microservices and lightweight HTTP handlers.

## Install

Save as a script file and run:

# Polka — Micro Web Server for Node.js

## Quick Use
```bash
npm install polka
```
```javascript
const polka = require("polka");

polka()
  .get("/", (req, res) => {
    res.end("Hello from Polka!");
  })
  .listen(3000, () => {
    console.log("Running on localhost:3000");
  });
```

## Introduction
Polka is a micro web server for Node.js that delivers Express-like routing in a tiny footprint. It uses a Trouter-based path matcher for fast route resolution and maintains API compatibility with Express middleware, so existing middleware like cors, helmet, and body-parser work out of the box.

## What Polka Does
- Routes HTTP requests with Express-compatible method handlers (get, post, put, delete)
- Resolves routes using Trouter, a lightweight trie-based path matcher
- Supports middleware via `.use()` with the same (req, res, next) signature as Express
- Handles parameterized routes and wildcard patterns
- Returns a native http.Server, allowing direct access to Node.js server methods

## Architecture Overview
Polka wraps Node.js's built-in http.createServer with a thin routing layer. Incoming requests are matched against a trie of registered routes via the Trouter library. Matched handlers execute in sequence with middleware running first. There is no built-in body parser, template engine, or view layer — Polka provides only the router and middleware pipeline, keeping the total package size under 5 KB.

## Self-Hosting & Configuration
- Requires Node.js 12 or later
- Install with `npm install polka`
- Attach middleware with `.use()` before defining routes
- Call `.listen(port)` to start; returns a native http.Server instance
- Deploy behind a reverse proxy (Nginx, Caddy) for TLS and load balancing

## Key Features
- Under 5 KB total size, with no dependencies beyond Trouter
- Express-compatible middleware signature for ecosystem compatibility
- Trie-based routing is faster than Express's linear route matching
- Returns a standard http.Server for direct integration with Node.js APIs
- Supports async handlers via returned Promises or async functions

## Comparison with Similar Tools
- **Express** — the standard Node.js framework; Polka is 30-50x smaller with faster routing
- **Fastify** — schema-based validation and plugin system; Polka is simpler and smaller
- **Koa** — async-first with context objects; Polka keeps the Express req/res signature
- **Hono** — multi-runtime edge framework; Polka targets Node.js specifically
- **uWebSockets.js** — C++ backed for raw speed; Polka uses standard Node.js http

## FAQ
**Q: Can I use Express middleware with Polka?**
A: Yes. Polka supports the standard (req, res, next) middleware signature, so most Express middleware works without changes.

**Q: Does Polka support TypeScript?**
A: Type definitions are available via `@types/polka` on npm.

**Q: Is Polka suitable for production?**
A: Yes. Its small surface area and use of native http.Server make it production-ready when paired with a reverse proxy.

**Q: How does Polka handle errors?**
A: Polka provides an `onError` handler and a `onNoMatch` handler for 404s. Middleware can call `next(err)` to trigger error handling.

## Sources
- https://github.com/lukeed/polka
- https://github.com/lukeed/polka#readme

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Source: https://tokrepo.com/en/workflows/asset-2fbab3e6
Author: Script Depot