Event tracking

Browser and Node clients share the same core methods:

• identify(userId, traits) sets the user and queues an identify-side effect according to the core client.
• setTraits / setTrait update traits without a new user id.
• reset() clears the identity. Flag state is dropped so the next user does not inherit flags.
• track(name, properties) queues a track event and returns immediately.
• trackDurable(name, properties) waits until the event is persisted locally.
• flush(timeoutMs) pushes the queue.
• shutdown(timeoutMs) flushes and stops.

On Node, track also accepts { event, userId, properties }. If userId is set, the client identifies first. withIdentity({ userId, anonymousId, traits }) returns a new client bound to that identity, which is the usual server pattern per request.

React applications should call useTrack() rather than importing a global client into a render.