Frames may carry arbitrary extra fields.
OptionalchannelThe channel the frame targets.
OptionaleventThe event name (for data frames).
OptionalpayloadThe payload (for data frames).
OptionaltypeThe frame kind (event, subscribe, unsubscribe); absent frames are treated as data.
The wire frame exchanged with clients (and the isomorphic
@stone-js/realtimeclient): atype, achannel, and for data frames aneventandpayload.