koa-ratelimit

Rate limiter middleware for koa

koa-ratelimit

Rate limiter middleware for koa.

Installation

$ npm install koa-ratelimit

Example

var ratelimit = require('koa-ratelimit');
var redis = require('redis');
var koa = require('koa');
var app = koa();
 
// apply rate limit 
 
app.use(ratelimit({
  db: redis.createClient(),
  duration: 60000,
  max: 100,
  id: function (context) {
    return context.ip;
  },
  headers: {
    remaining: 'Rate-Limit-Remaining',
    reset: 'Rate-Limit-Reset',
    total: 'Rate-Limit-Total'
  }
}));
 
// response middleware 
 
app.use(function *(){
  this.body = 'Stuff!';
});
 
app.listen(3000);
console.log('listening on port 3000');

Options

db redis connection instance
max max requests within duration [2500]
duration of limit in milliseconds [3600000]
id id to compare requests [ip]
headers custom header names
remaining remaining number of requests ['X-RateLimit-Remaining']
reset reset timestamp ['X-RateLimit-Reset']
total total number of requests ['X-RateLimit-Limit']

Responses

Example 200 with header fields:

HTTP/1.1 200 OK
X-Powered-By: koa
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 99
X-RateLimit-Reset: 1384377793
Content-Type: text/plain; charset=utf-8
Content-Length: 6
Date: Wed, 13 Nov 2013 21:22:13 GMT
Connection: keep-alive
 
Stuff!

Example 429 response:

HTTP/1.1 429 Too Many Requests
X-Powered-By: koa
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 0
X-RateLimit-Reset: 1384377716
Content-Type: text/plain; charset=utf-8
Content-Length: 39
Retry-After: 7
Date: Wed, 13 Nov 2013 21:21:48 GMT
Connection: keep-alive
 
Rate limit exceeded, retry in 8 seconds