Trading market data
All reads below are JSON requests to the same endpoint:
The type field selects the operation.
Discover outcomes with Predict
Use the Predict Outcomes API for outcome labels, questions, lifecycle status, Hyperliquid identifiers, hl_settle_fraction, current YES and NO marks, trades, statistics, holders, and timeseries. Subscribe to the Predict realtime API for matching live state.
Use Hyperliquid directly when you need the full order book, venue-wide mids, candles, or raw exchange messages. The direct-trading reference intentionally does not expose Hyperliquid outcome-metadata requests.
Use Hyperliquid exchangeStatus only for exchange time and special operating state.
Prices and activity
Derive best bid, best ask, midpoint, and spread from the first levels of l2Book. Unlike some prediction exchanges, Hyperliquid does not expose separate outcome routes for each derived price.
Snapshot handling
HTTP l2Book and WebSocket l2Book messages are replacement snapshots. Replace the local book atomically. They are not sequenced deltas, so a compatibility gateway that promises delta semantics must calculate and sequence those deltas itself.
Start with Get order book, then use the separate reference page for each additional read operation.