ratelimiter

Rate limiter for nodejs backed by redis.

Installation

$ npm install ratelimiter

Example

Example Connect middleware implementation limiting against a user._id:

var id = req.user._id;
var limit = new Limiter({ id: id, db: db });
limit.get(function(err, limit){
  if (err) return next(err);

  res.set('X-RateLimit-Limit', limit.total);
  res.set('X-RateLimit-Remaining', limit.remaining);
  res.set('X-RateLimit-Reset', limit.reset);

  // all good
  debug('remaining %s/%s %s', limit.remaining, limit.total, id);
  if (limit.remaining) return next();

  // not good
  var delta = (limit.reset * 1000) - Date.now() | 0;
  var after = limit.reset - (Date.now() / 1000) | 0;
  res.set('Retry-After', after);
  res.send(429, 'Rate limit exceeded, retry in ' + ms(delta, { long: true }));
});

Options

• id the identifier to limit against (typically a user id)
• db redis connection instance
• max max requests within duration [2500]
• duration of limit in milliseconds [3600000]

License

MIT