Transcription

The <Transcription> verb enables real-time speech-to-text transcription for the call.

ATTRIBUTE	DESCRIPTION	OPTIONS	DEFAULT
language	Language to use for speech recognition. See languages in transcription_engine_config.		en
interimResults	Whether to send also interim results. If set to false, only final results will be sent. Applies to transcriptionEngine A only.		false
transcriptionEngine	Engine to use for speech recognition. Available engines: Google (default), Telnyx, Deepgram. Each engine supports different models and languages - see model attribute and examples below. Legacy values "A" (maps to Google) and "B" (maps to Telnyx) are supported for backward compatibility.	Google, Telnyx, Deepgram, A, B	Google
transcriptionTracks	Indicates which leg of the call will be transcribed. Use inbound for the leg that requested the transcription, outbound for the other leg, and both for both legs of the call.	inbound, outbound, both	inbound
transcriptionCallback	URL that tells Telnyx where to make its GET or POST requests with transcription data.		-
transcriptionCallbackMethod	HTTP request type used for transcriptionCallback.	GET, POST	POST
model	Optional model to use with the specified transcription engine. If not specified, the engine's default model will be used. See transcription models in transcription_engine_config.		-

Example 1: Basic transcription using Google (default)

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Transcription language="en" interimResults="true" transcriptionCallback="/transcription" />
  </Start>
</Response>

Example 2: Google with phone call optimized model

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Transcription
      transcriptionEngine="Google"
      model="phone_call"
      language="en-US"
      interimResults="true"
      transcriptionCallback="/transcription" />
  </Start>
</Response>

Example 3: Telnyx engine with Whisper model

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Transcription
      transcriptionEngine="Telnyx"
      model="openai/whisper-large-v3-turbo"
      language="es"
      transcriptionCallback="/transcription" />
  </Start>
</Response>

Example 4: Deepgram with Nova-3 model

<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Transcription
      transcriptionEngine="Deepgram"
      model="deepgram/nova-3"
      language="fr"
      transcriptionCallback="/transcription" />
  </Start>
</Response>

transcription-callback

{
    "AccountSid": params.user_id,
    "CallSid" => call_sid,
    "CallSidLegacy" => call_sid,
    "Transcript" => params.transcript,
    "IsFinal" => params.is_final,
    "Confidence" => params.confidence
}

ATTRIBUTE	DESCRIPTION
AccountSid	A unique identifier for the account generating this call.
CallSid	A unique identifier for this call, generated by Telnyx.
CallSidLegacy	A unique identifier for the call sent to keep backward compatibility.
Transcript	The result of the transcription.
IsFinal	Indicates if the provided transcription is final, supported by engine A only
Confidence	Indicates the level of confidence in the accuracy of the transcription. Possible value 1 (high confidence) - 0 (low confidence), supported by engine A only