fastapi-easylimiter 0.2.2

High-performance async rate limiter for FastAPI with Redis or native in-memory backend

fastapi-easylimiter

Simple ASGI async rate-limiting middleware for FastAPI with Redis or in-memory caching.

Simple design

• Async rate limiting
• Cache
  • Redis
  • In-Memory (single worker dev)
• Path Based Rules
• Multi-rule prefix matching
  • Can do global ratelimits and per-route
• Standard rate-limit headers
  • X-RateLimit-Limit
  • X-RateLimit-Remaining
  • X-RateLimit-Reset
  • Retry-After on 429 responses
• Proxy Aware
  • Uses 'X-Forwarded-For' only when the sender is trusted
  • Rejects spoofed XFF headers

Installation

pip install fastapi-easylimiter

---

Usage

from fastapi import FastAPI
from fastapi_easylimiter import AsyncRedisBackend, InMemoryBackend, RateLimiterMiddleware
import redis.asyncio as redis_async

app = FastAPI()

REDIS_URL = "redis://localhost:6379/0"

# Redis backend (recommended for multi-instance deployments)
redis_client = redis_async.from_url(REDIS_URL, decode_responses=True)
backend = AsyncRedisBackend(redis_client)

# Or for single-instance/local development:
# backend = InMemoryBackend()

rules = {
    "/api/": {"limit": 60, "period": 60},
    "/api/users": {"limit": 1, "period": 2},
}

app.add_middleware(
    RateLimiterMiddleware,
    rules=rules,
    backend=backend,
    trusted_proxies=["127.0.0.1"]
)

Rules are automatically sorted longest-first as seen in the code example.

A request to /api/users/me will match:

• /api/users
• /api

Both rules count independently.

If ANY rule is exceeded → request becomes 429.

Contributing

Contributions and forks are always welcome! Feel free to adapt, improve, or extend this middleware for your own needs. This was purely made out of personal necessity.

Support