Rate limiting design

Skill AtulPurohit/Antigravity-Awesome-Skills/skills/rate-limiting-design

Design and implement rate limiting strategies to protect APIs and services from abuse while maintaining quality of service.From its SKILL.md

Install

npx -y skills add AtulPurohit/Antigravity-Awesome-Skills --skill rate-limiting-design

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

2 things to look at

no licenseNo license file was found in the repository. Code published without one is not open source by default, so using it at work is a question for whoever answers licensing questions where you are.
3 stars3 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

SKILL.md

2.1 KB, 433 tokens by cl100k_base, as published. Nobody here has run it

Rate Limiting Designer

Purpose

Protect APIs and services from abuse, ensure fair usage, and maintain system stability under high load.

Rate Limiting Algorithms

Fixed Window

Simplest: Count requests per time window
Problem: Allows 2x burst at window boundary

Window: 10 requests per minute
Key: user:123:2026-07-10-10:30

Sliding Window (Recommended)

def check_rate_limit(user_id: str, limit: int, window: int) -> bool:
    now = time.time()
    window_start = now - window
    key = f"ratelimit:{user_id}"
    
    # Remove expired entries
    redis.zremrangebyscore(key, '-inf', window_start)
    
    # Count in current window
    count = redis.zcard(key)
    if count >= limit:
        return False
    
    # Add current request
    redis.zadd(key, {str(now): now})
    redis.expire(key, window)
    return True

Token Bucket

Best for: Allowing bursts up to bucket capacity
Bucket: 100 tokens, refill 10/second
Each request: costs 1 token
Burst allowed: up to 100 requests instantly

Response Headers

X-RateLimit-Limit: 100        # Limit per window
X-RateLimit-Remaining: 45     # Requests remaining
X-RateLimit-Reset: 1625000000 # Unix timestamp of window reset
Retry-After: 60               # Seconds until retry allowed (429 only)

Tiered Rate Limits

Anonymous: 20 requests/minute
Free tier: 100 requests/minute
Pro tier: 1000 requests/minute
Enterprise: Custom

Outputs

Rate limiting middleware implementation
Per-endpoint limit configuration
Response header standards
Bypass allowlist for internal services
Monitoring and alerting for rate limit events

What ships with it

Read from the repository

Just SKILL.md. No reference files, no scripts.