🚀 @ajay9299/rate-limiter

A simple and flexible Token Bucket based Rate Limiter middleware for Express.js.

📦 Installation

npm install @ajay9299/rate-limiter

⚡ Quick Start

import express from 'express';
import { RateLimiter } from '@ajay9299/rate-limiter';

const app = express();
const limiter = new RateLimiter();

app.use(
  limiter.middleware(
    (req) => req.ip, // keyGenerator
    () => 5,         // capacity (max tokens)
    () => 1          // refill rate (tokens per second)
  )
);

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

⚙️ Configuration

middleware parameters:

| Parameter | Type | Description | | ------------ | ----------------- | ----------------------- | | keyGenerator | (req) => string | Unique key per user/IP | | capacity | (req) => number | Max tokens in bucket | | refillRate | (req) => number | Tokens added per second |

🧠 How it works

• Each request consumes 1 token
• Tokens refill over time
• If no tokens → request is rejected (429)

📌 Per Route Rate Limiting

app.use(
  '/user',
  limiter.middleware(
    (req) => `${req.ip}:user`,
    () => 10,
    () => 2
  )
);

app.use(
  '/post',
  limiter.middleware(
    (req) => `${req.ip}:post`,
    () => 5,
    () => 1
  )
);

🔥 Advanced Key Example

(req) => `${req.ip}:${req.baseUrl}:${req.method}`

🚧 Future Enhancements

• Redis support (distributed rate limiting)
• Sliding window algorithm
• Rate limit headers
• Auto cleanup of buckets

📄 License

ISC