Hyperliquid WebSocket

Read-only, no key. Endpoints: wss://api.hyperliquid.xyz/ws (mainnet), wss://api.hyperliquid-testnet.xyz/ws (testnet). Prefer WebSocket over polling for anything continuous: fills, order updates, book and price watches.

Protocol

Subscribe: {"method": "subscribe", "subscription": {...}}. Unsubscribe with "method": "unsubscribe". The server acknowledges with {"channel": "subscriptionResponse", ...} then streams {"channel": "<type>", "data": ...}. Send {"method": "ping"} periodically (the SDKs do it for you; the server expects activity within about a minute) and expect {"channel": "pong"}.

Subscription types the desk uses: