Api Rate Limiting

class TokenBucket {  constructor(capacity, refillRate) {    this.capacity = capacity;    this.tokens = capacity;    this.refillRate = refillRate; // tokens per second    this.lastRefill = Date.now();  }
  consume() {    this.refill();    if (this.tokens >= 1) {      this.tokens--;      return true;    }    return false;  }
  refill() {    const now = Date.now();    const elapsed = (now - this.lastRefill) / 1000;    this.tokens = Math.min(this.capacity, this.tokens + elapsed * this.refillRate);    this.lastRefill = now;  }}

const rateLimit = require('express-rate-limit');
const limiter = rateLimit({  windowMs: 15 * 60 * 1000, // 15 minutes  max: 100,  standardHeaders: true,  message: { error: 'Too many requests, try again later' }});
app.use('/api/', limiter);