koa-ratelimit

Rate limiter middleware for koa.

Installation

$ npm install koa-ratelimit

Example

const Koa = require('koa');
const ratelimit = require('koa-ratelimit');
const redis = require('ioredis');
const app = new Koa();
 
// apply rate limit 
 
app.use(ratelimit({
  db: new Redis(),
  duration: 60000,
  errorMessage: 'Sometimes You Just Have to Slow Down.',
  id: (ctx) => ctx.ip,
  headers: {
    remaining: 'Rate-Limit-Remaining',
    reset: 'Rate-Limit-Reset',
    total: 'Rate-Limit-Total'
  },
  max: 100
}));
 
// response middleware 
 
app.use(async (ctx) => {
  ctx.body = 'Stuff!';
});
 
app.listen(3000);
console.log('listening on port 3000');

Options

db redis connection instance
duration of limit in milliseconds [3600000]
errorMessage custom error message
id id to compare requests [ip]
headers custom header names
max max requests within duration [2500]
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