Skip to main content
The best WebSocket market-data API keeps live state and replays history on the same socket, handles gaps, and recovers from disconnects without corrupting the local book. 0xArchive does that for Hyperliquid and Lighter, from trades and L2 depth to per-order L4 streams. Subscribe to live updates or replay an exact historical window through one connection, with the same channel names and the same message shapes. Every order, trade, and fill, one API.

One Socket, Live And Replay

Streaming capability0xArchive
Live subscriptionsReal-time order books, trades, funding, OI, and liquidations for Hyperliquid and Lighter
Exact-window replayReplay any historical window on the same socket, in original sequence
L4 order-book streamsPer-order Hyperliquid book updates for live local-state maintenance
Channel selectionPick venue family, symbol, and channel with consistent message shapes
Gap handlingSequence and gap events so the client knows when to rebuild local state
Tier-aware limitsSubscription counts scale by plan, from Free through Enterprise

Where To Start

Streaming needStart
Connect and keep aliveWebSocket connection
Live subscriptionsWebSocket real-time streams
Channel selectionWebSocket channels
Replay and backtestingWebSocket backtesting
L4 local book workflowsWebSocket L4 order book
Limits and tiersWebSocket tier limits

How To Choose A WebSocket Vendor

Ask four questions of any streaming API before writing the client:
QuestionWhy it decides
Does replay use the live message shapes?If replay is a separate REST format, the backtest exercises a different parser than production
Are gaps announced or silent?A client that cannot tell a quiet market from a dropped sequence corrupts its local book
How fast can a window replay?Replay speed sets iteration time; 0xArchive scales it by plan, 10x on Free through 300x on Scale and from 500x on Enterprise
Where does the key travel?Header or token auth keeps keys out of URLs, logs, and browser history
The first question eliminates the most vendors: live-only feeds force you to record your own history before the first backtest can run.

When To Use 0xArchive

The same socket that streams live Hyperliquid and Lighter updates also replays an exact historical window in original sequence, so a backtest and a live client run identical code paths. L4 streams carry per-order Hyperliquid book updates for local-state maintenance, and every channel emits sequence and gap events so the client knows exactly when to discard and rebuild. Secrets stay in an environment or backend-controlled path, never in prompt text or browser URLs. Every channel and replay window is available on every tier, including Free; plans change subscription counts and replay speed, not which streams you can open. 0xArchive is not the right fit when the stream you need belongs to a centralized exchange; it carries Hyperliquid and Lighter. Every order, trade, and fill. One API.

Next Step

Start with WebSocket connection, choose the channel in WebSocket channels, then add WebSocket tier limits and a gap-recovery rule before running a live client. For order-level streams, run one WebSocket L4 order book test, then compare plans.
Last modified on July 4, 2026