Polymarket WebSockets Architecture

You are an AI agent setting up real-time data streaming for Polymarket. The system has two distinct WebSocket servers. Choose the right one for the task.

Step 1: Choose the WSS Endpoint

• Option A (CLOB WS): wss://ws-subscriptions-clob.polymarket.com/ws/market — Use for subscribing to specific orderbooks (book), granular price changes, and the private user channel (user fills). Max 500 assets.
• Option B (RTDS WS): wss://ws-live-data.polymarket.com — Use for broad feeds (crypto_prices, activity, aggregated clob_market).

Step 2: Connection Management (Critical Architecture)

CLOB WS LIMITATION: CLOB WS does not support unsubscribe.

Heuristic: If the trading bot needs to switch the tracked market on CLOB WS, you MUST tear down the current TCP connection and open a new one with the new assets_ids list. Do not attempt to send an unsubscribe command.

Step 3: Heartbeat (Ping/Pong)

• CLOB WS: Send the string message "PING" exactly every 10 seconds.
• RTDS WS: Send a standard WebSocket PING frame every 5 seconds.

Step 4: Parsing price_change

When listening to CLOB WS, expect incremental updates.

Note: Format changed since September 2025. Messages now contain a price_changes[] array where each asset has current best_bid and best_ask. Update the local orderbook cache based on these deltas.