CtrlK
BlogDocsLog inGet started
Tessl Logo

api-rate-limiting

Implements API rate limiting using token bucket, sliding window, and Redis-based algorithms to protect against abuse. Use when securing public APIs, implementing tiered access, or preventing denial-of-service attacks.

Install with Tessl CLI

npx tessl i github:secondsky/claude-skills --skill api-rate-limiting
What are skills?

Overall
score

89%

Review — 89%

Does it follow best practices?

Validation — 13 / 16 Passed

Validation for skill structure

SKILL.md
Review
Evals

API Rate Limiting

Protect APIs from abuse using rate limiting algorithms with per-user and per-endpoint strategies.

Algorithms

AlgorithmProsCons
Token BucketHandles bursts, smoothMemory per user
Sliding WindowAccurateMemory intensive
Fixed WindowSimpleBoundary spikes

Token Bucket (Node.js)

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;
  }
}

Express Middleware

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);

Response Headers

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 45
X-RateLimit-Reset: 1705320000
Retry-After: 60

Tiered Limits

TierRequests/Hour
Free100
Pro1,000
Enterprise10,000

Best Practices

  • Use Redis for distributed rate limiting
  • Include proper headers in responses
  • Return 429 status with Retry-After
  • Implement tiered limits for different plans
  • Monitor rate limit metrics
  • Test under load
Repository
github.com/secondsky/claude-skills
Last updated
Created

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.

Claim skill