Presence

Presence v2 runs over /sync/stream alongside bucket pings.

import { track, untrack, presenceState, onPresence, subscribePresence } from "@nizhal/db-collection";

echo.track("myNotes", { ownerId }, { status: "online", device: "ipad" });

const off = onPresence("myNotes", { ownerId }, (diff) => {
  // diff.joins / diff.leaves with presence_ref
});

echo.untrack("myNotes", { ownerId });

Server enforces heartbeat timeout via presence config on createNizhalServer. State and diffs are bucket-scoped — same scope rules as data sync.

Presence does not carry row data and is not authoritative for convergence — cursor pull is.

React Native

Same API on createNizhalNitroClient. WS reconnect re-establishes presence after catch-up pull.