ok.
Order no longer resting. Query orderStatus by client ID before deciding what to send next. Successful cancels return "success" in the corresponding statuses entry.
Errors affecting the whole action use:
Cancel responses describe gateway state. Older on-chain publications can still execute until replaced or expired. Continue tracking fills for canceled and replaced IDs.
While a maker has pending order changes,
orderStatus, openOrders, frontendOpenOrders, and historicalOrders return HTTP 503 with Order state persistence pending. WebSocket info requests return the same message as a post error. This response does not mean the order is absent. Keep retrying the query with backoff; normal order reads resume when the change is durable or authoritative recovery has resolved it. Other makers remain queryable.
Invalid or unsupported /info requests return HTTP 422. Unsupported WebSocket requests/subscriptions return an error response or channel. Book price aggregation, aggregated fill history, and unsupported Hyperliquid trading/funding actions fail explicitly.