OptionalcapabilitiesOptionalisfalse for groups/channels: native drafts are attempted only when not false.
OptionalshutdownAborted when the transport shuts down (bot.stop()): the stream is cancelled and
touches the target no more — no flush, no discard, no rate-limit wait.
Optionaloptions: SendOptionsOptionaleditOptionaldeleteDeletes a message this stream sent (used by onCancel: 'discard').
OptionaldraftOptionalopts: DraftOptionsOptionaltyping
The sink streamText renders into.
ctx.stream()builds one from the bot; tests and custom integrations can provide their own.