POST /api/v2/recording/recordings/{recordingId}/transcription not starting

Trying to kick off transcription programmatically. Hit POST /api/v2/recording/recordings/{recordingId}/transcription with an empty body but get a 400 Bad Request.

{ "error_code": "invalid_request", "message": "Body is required" }

What payload does it actually want?

You need to send an empty JSON object {} instead of a completely empty body. The API parser is strict about receiving valid JSON.

{}