Crypto Price WebSocket Project

Real-time BTC/ETH/BNB price streaming via Binance WebSocket → FastAPI server → clients.

Live Demo

👉 https://crypto-websocket-fastapi.onrender.com/

Open the link to see the live crypto dashboard.

Architecture

Binance WSS ──► binance_listener() ──► asyncio.Queue ──► broadcaster()
                                                               │
                                               ┌──────────────┘
                                               ▼
                                    ConnectionManager.broadcast()
                                               │
                              ┌────────────────┼────────────────┐
                              ▼                ▼                ▼
                          Client A         Client B         Client C

Features

Feature	Details
Multiple pairs	BTC/USDT, ETH/USDT, BNB/USDT
Local WS server	ws://localhost:8000/ws
REST API	GET /price?symbol=BTCUSDT, GET /prices
Rate limiting	30 req/min on REST endpoints
Connection limit	Max 50 concurrent WS clients
Graceful disconnects	Dead clients removed automatically
asyncio.Queue	Fan-out message bus
Auto-reconnect	Exponential back-off on Binance drop
Demo UI	Browser dashboard at http://localhost:8000
Docker	Single docker compose up

Run Locally (without Docker)

pip install -r requirements.txt
uvicorn main:app --reload

Open http://localhost:8000 for the live dashboard.

Run with Docker

docker compose up --build

API Reference

WebSocket

Local:

ws://localhost:8000/ws

Production:

wss://crypto-websocket-fastapi.onrender.com/ws

{
  "symbol": "BTCUSDT",
  "last_price": 68421.5,
  "change_pct": 1.23,
  "timestamp": "2024-11-01T10:00:00Z"
}

REST

Method	Path	Description
GET	/price?symbol=BTCUSDT	Latest price for one symbol
GET	/prices	All latest prices
GET	/health	Server health + client count

Test the WebSocket (CLI)

# Install wscat
npm install -g wscat

# Local
wscat -c ws://localhost:8000/ws

# Production
wscat -c wss://crypto-websocket-fastapi.onrender.com/ws

Test the REST API

# Local
curl http://localhost:8000/price?symbol=ETHUSDT

# Production
curl https://crypto-websocket-fastapi.onrender.com/price?symbol=ETHUSDT

📌 Notes

• Uses secure WebSocket (wss://) in production
• Designed using producer-consumer pattern (asyncio.Queue)
• Backend acts as both:
  • WebSocket client (Binance)
  • WebSocket server (clients)

👨‍💻 Author

Laraib Ahmed

• GitHub: https://github.com/Laraib-1629