Track length in milliseconds.
The current entity id (album/playlist/…), or null.
The current entity type, or null.
Whether playback is paused.
The current playable id, or null when nothing is playing.
Live-extrapolated playback position in milliseconds (see liveProgressMs).
The resolved track, when a resolver is configured and resolution succeeded.
A synchronous snapshot of what is playing right now, pulled from the last received state frame. Unlike the push events, this is available at any time (for example to answer an HTTP request) without waiting for the next frame.