Combine streaming with backfill

Beta

HyperCore APIs are in beta. Message fields, limits, and behavior may change, including breaking changes. To request access, contact [email protected].

Streams replay only recent blocks. If a fill stream returns a gap, or a client was offline longer than the replay window, the missing range has to come from another source.

Record every gap range (fromBlock to toBlock, inclusive) and any outage longer than the replay window.
Continue processing live data; don't block on the backfill.
Fill the missing range from a historical source, deduplicating on tid plus user.

HyperCore REST and historical data aren't part of the current beta. To recover a wallet's fills for a missed range, use Hyperliquid's userFillsByTime info request, and keep outages short so replay covers them.

Book streams don't need backfill: resubscribe and the snapshot gives you current state.