caching-proxy-python

Flask and FastAPI based caching proxy server with TTL, clear cache and X-Cache headers

Caching Proxy Server in Python

This project is a simple proxy server with caching support using Flask and FastAPI.
It forwards requests to an origin server and caches responses, adding headers to indicate cache status (X-Cache: HIT / MISS).

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📁 Files

• caching_proxy.py: Flask-based version
• proxy_fastapi.py: FastAPI version

It acts as a middle layer between the client and an origin server, caching GET responses and returning X-Cache: HIT or MISS.

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🚀 Features

✅ Caching for GET requests
✅ Auto-expiry using TTL
✅ X-Cache response header
✅ Clear Cache with /clear-cache endpoint
✅ Persistent caching using pickle
✅ Support for POST/PUT/DELETE passthrough (FastAPI)

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🛠️ Installation

1. Clone the Repo

git clone https://github.com/YOUR_USERNAME/caching-proxy-python.git
cd caching-proxy-python

2. Create Virtual Environment (optional but recommended)

python -m venv venv
source venv/bin/activate  # macOS/Linux
venv\Scripts\activate     # Windows

3. Install Dependencies

(Separate installations) For Flask version:

pip install flask requests

For FastAPI version:

pip install fastapi uvicorn httpx

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💻 Requirements

Install dependencies using:

pip install flask fastapi uvicorn requests

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▶️ How to Run

Flask Proxy version:

python caching_proxy.py --origin http://dummyjson.com --port 3000 --ttl 60

Then open in browser:

http://localhost:3000/products

You’ll get:

X-Cache: MISS on first call

X-Cache: HIT on subsequent calls

X-Cache: MISS again after TTL expires

To clear cache:

http://localhost:3000/clear-cache

FastAPI Proxy version:

python proxy_fastapi.py --origin http://dummyjson.com --port 3000 --ttl 60

Open in browser:

http://localhost:3000/products

FastAPI also supports:

POST/PUT/DELETE passthrough (with X-Cache: BYPASS)

Built-in docs: http://localhost:3000/docs

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Supported Endpoints

GET /products → fetch product data (cached)

POST /posts → add a new post (forwarded)

PUT /posts/1 → update a post (forwarded)

DELETE /posts/1 → delete a post (forwarded)

GET /clear-cache → clears the cache manually

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Sample CURL Commands

GET (cached):

curl http://127.0.0.1:3000/products

First time: X-Cache: MISS Next time: X-Cache: HIT

POST:

curl -X POST http://127.0.0.1:3000/posts -H "Content-Type: application/json" -d "{\"title\": \"New Post\"}"

PUT:

curl -X PUT http://127.0.0.1:3000/posts/1 -H "Content-Type: application/json" -d "{\"title\": \"Updated Post\"}"

DELETE:

curl -X DELETE http://127.0.0.1:3000/posts/1

Clear cache:

curl http://127.0.0.1:3000/clear-cache

Auto Expiry (TTL) The server automatically expires cache entries after 60 seconds (FastAPI version).

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🚀 Project Page

https://github.com/rhakia/caching-proxy-python

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Inspired by

Roadmap.sh's Caching Proxy Python project idea.

https://roadmap.sh/projects/caching-server