I'm sorry to hear you're encountering the error "failed to send transcription, room closed: channel closed." This usually happens when there's an attempt to send a transcription message to a room that has already been closed. Essentially, the communication channel for that room is no longer active, so the operation can't go through. In LiveKit, rooms can close automatically when everyone leaves, due to an idle timeout, or they can be closed explicitly using server APIs like

DeleteRoom

or

RemoveParticipant

. Once a room is closed, it’s important to know that no more data, including transcriptions, can be sent to it. To help prevent this error, I recommend checking the room's connection state before trying to publish any transcription data. You can use room event callbacks to keep track of the room’s status and gracefully stop transcription publishing if the room disconnects for reasons like

ROOM_CLOSED

or

ROOM_DELETED

. If you need any help setting this up, please feel free to ask—I’m here to help! Sources: libwebrtc/src/data_channel.rs | Connecting to LiveKit | LiveKit Docs