api-rate-limiter

Rate limiter package for Express server API requests

API ✍

api-rate-limiter API

init(...)

Parameter	Description	Required	Default
payload.client	RedisClient instance (promisified)	✔	✘
payload.serverName	API server name	✔	✘

Sample:

   const RateLimiter = require('api-rate-limiter')
   
   const Promise = require('bluebird')
   const redis = require('redis')
   
   Promise.promisifyAll(redis.RedisClient.prototype)
   const redisClient = redis.createClient()
   
   RateLimiter.init({ client: redisClient, serverName: 'code-mentor-api' })

RateLimiter should be initialized before initializing API routes.

Errors

Error name	Description
RateLimiterInvalidRedisClientError	Error thrown in case of invalid redis client
RateLimiterInvalidServerNameError	Error thrown in case of invalid server name parameter

preventRateLimitAbuse(...)

Parameter	Description	Required	Default
payload.maxNumberOfRequests	Maximum allowed requests per time window	✔	✘
payload.rateLimitWindowInSeconds	Rate limit time window in seconds	✘	300 seconds

Sample:

  const express = require('express')
  const router = express.Router()

  const RateLimiter = require('api-rate-limiter')

  router.get('/',
    RateLimiter.preventRateLimitAbuse({ maxNumberOfRequests: 50,  rateLimitWindowInSeconds: 600 }),
    function (req, res, next) {
        ...request handler code
    })

Errors

Error name	Description
RateLimitExceededError	Error passed to the next() middleware function in case of rate limit abuse
RateLimiterMissingRedisClientError	Error thrown in case of missing redis client for rate limiter
RateLimiterMissingServerNameError	Error thrown in case of missing server name for rate limiter

HTTP Headers

Header	Description
X-RateLimit-Limit	Requests permitted to make per time window
X-RateLimit-Remaining	Requests remaining in the current time window
X-RateLimit-Reset	UNIX timestamp detailing when the rate limit will reset

Sample:

X-RateLimit-Limit: 50
X-RateLimit-Remaining: 42
X-RateLimit-Reset: 1541169284467