Building a Sub-200ms Polymarket & Crypto WebSocket Listener in Python

#python #ai #web3 #quant

Building a Sub-200ms Polymarket WebSocket Listener in Python

In modern prediction markets and quantitative finance, speed is everything. Capturing arbitrage opportunities before manual traders react requires a sub-second streaming pipeline.

In this tutorial, we will build a production-ready asynchronous Python WebSocket listener that parses live orderbook changes on Polymarket in under 200ms.

1. Prerequisites

Python 3.10+
websockets, aiohttp, asyncio

pip install websockets aiohttp

2. Core Asynchronous WebSocket Architecture

import asyncio
import json
import websockets

CLOB_WS_URL = "wss://ws-subscriptions-clob.polymarket.com/ws/market"

async def subscribe_orderbook(token_id):
    async with websockets.connect(CLOB_WS_URL) as ws:
        subscribe_msg = {
            "type": "market",
            "assets_ids": [token_id]
        }
        await ws.send(json.dumps(subscribe_msg))
        print(f"Connected to Polymarket WS Stream for token {token_id[:10]}...")

        while True:
            msg = await ws.recv()
            data = json.loads(msg)
            # Process sub-200ms price update
            print("Live Orderbook Update:", data)

if __name__ == "__main__":
    asyncio.run(subscribe_orderbook("75212375517444662942705581008505477009916343680049771629804936585862986754319"))

3. Production Turnkey SDK

If you want the complete production-grade SDK with automated 48h market batch scanning, EIP-712 security guardrails, and automated limit order placement, check out the YieldStream Quant API Kit on our storefront:

👉 YieldStream Quant API Kit Pro SDK