Expressive HTTP middleware for node.js to make web applications and APIs more enjoyable to write. Koa's middleware stack flows in a stack-like manner, allowing you to perform actions downstream then filter and manipulate the response upstream. Koa's use of generators also greatly increases the readability and robustness of your application.
Only methods that are common to nearly all HTTP servers are integrated directly into Koa's small ~550 SLOC codebase. This includes things like content negotiation, normalization of node inconsistencies, redirection, and a few others.
Koa is not bundled with any middleware.
$ npm install koa
Koa requires node v4.0.0 or higher for (partial) ES2015 support.
- API documentation
- Badgeboard and list of official modules
- Examples
- Middleware list
- Wiki
- G+ Community
- Reddit Community
- Mailing list
- Guide
- FAQ
- 中文文档
- #koajs on freenode
- Kick-Off-Koa - An intro to koa via a set of self-guided workshops.
- Workshop - A workshop to learn the basics of koa, Express' spiritual successor.
- Introduction Screencast - An introduction to installing and getting started with Koa
const Koa = require('koa');
const app = new Koa();
// logger
app.use(function *(next){
const start = new Date;
yield next;
const ms = new Date - start;
console.log(`${this.method} ${this.url} - ${ms}`);
});
// response
app.use(function *(){
this.body = 'Hello World';
});
app.listen(3000);$ make test
See AUTHORS.
MIT