Expressive middleware for node.js using generators via co to make writing web applications and REST APIs more enjoyable to write.
Only methods that are common to nearly all HTTP servers are integrated directly into Koa's small ~400 SLOC codebase. This includes things like content-negotiation, normalization of node inconsistencies, redirection, and a few others.
No middleware are bundled with koa. If you prefer to only define a single dependency for common middleware, much like Connect, you may use koa-common.
$ npm install koa
To use Koa you must be running node 0.11.4 or higher for generator support, and must run node(1)
--harmony-generators flag. If you don't like typing this, add an alias to your shell profile:
alias node='node --harmony-generators'
var koa = ;var app = ;// loggerapp;// responseapp;app;
$ make test
Average latency with one middleware:
Average latency with 400 noop middleware:
If you like silly benchmarks, here's the requests per second:
1 middleware 8083.45 5 middleware 7449.95 10 middleware 7166.66 15 middleware 6992.18 20 middleware 6650.28 30 middleware 6113.57 50 middleware 5117.46
With 50 middleware (likely much more than you'll need), that's 307,020 requests per minute, and 18,421,200 per hour, 442 million per day, so unless you're a facebook and can't manage to spin up more than one process to scale horizontally you'll be fine ;)