DeepThrottle

A rate limiting library for HTTP APIs built with FastAPI. Supports multiple rate limiting algorithms that can be swapped via configuration.

Algorithms

Algorithm	How it works
Token Bucket	Tokens refill at a fixed rate. Each request consumes a token. Denied when empty.
Leaky Bucket	Requests queue up and leak out at a fixed rate. Denied when queue is full.
Sliding Window Counter	Counts requests in a rolling time window using weighted overlap between adjacent windows.

Project Structure

DeepThrottle/
├── src/deepthrottle/
│   ├── __main__.py
│   ├── __init__.py
│   ├── api/
│   │   └── routes.py          # FastAPI endpoints and middleware
│   ├── algorithms/
│   │   ├── token_bucket.py    # Token bucket implementation
│   │   ├── leaky_bucket.py    # Leaky bucket implementation
│   │   └── sliding_window_counter.py  # Sliding window implementation
│   └── services/
│       ├── ratelimiter_services.py    # RateLimiter wrapper + AlgorithmType enum
│       └── benchmark.py    # Benchmarking
├── pyproject.toml
└── README.md

Setup

Requires Python 3.13+

# install dependencies
uv sync

# run the server
uvicorn deepthrottle.api.routes:app --reload

Endpoints

Method	Path	Description
middleware	http	Validate API key and rate limit requests
GET	/health	Health check
GET	/check/{key}	Get rate limit state for a key (planned)
POST	/create	Create a rate limiter for a given key
DELETE	/delete/{key}	Delete a rate limiter for a given key

Usage

from deepthrottle.services.ratelimiter_services import RateLimiter, AlgorithmType

limiter = RateLimiter(AlgorithmType.TOKEN_BUCKET, rate=10.0, capacity=100)
tokens, allowed, wait_time = limiter.allow()