Transcription start

POST 
/calls/:call_control_id/actions/transcription_start

Start real-time transcription. Transcription will stop on call hang-up, or can be initiated via the Transcription stop command.

Expected Webhooks (see callback schema below):

• call.transcription

Path Parameters

call_control_id stringrequired

Unique identifier and token for controlling the call

application/json

Body

required

Transcription start request

transcription_engine string

Possible values: [A, B]

Default value: A

Engine to use for speech recognition. A - Google, B - Telnyx.

transcription_engine_config

object

oneOf

• Transcription engine A config
• Transcription engine B config

language Google transcription engine list of languages (string)

Possible values: [af, sq, am, ar, hy, az, eu, bn, bs, bg, my, ca, yue, zh, hr, cs, da, nl, en, et, fil, fi, fr, gl, ka, de, el, gu, iw, hi, hu, is, id, it, ja, jv, kn, kk, km, ko, lo, lv, lt, mk, ms, ml, mr, mn, ne, no, fa, pl, pt, pa, ro, ru, rw, sr, si, sk, sl, ss, st, es, su, sw, sv, ta, te, th, tn, tr, ts, uk, ur, uz, ve, vi, xh, zu]

Default value: en

Language to use for speech recognition

interim_results boolean

Whether to send also interim results. If set to false, only final results will be sent.

enable_speaker_diarization boolean

Enables speaker diarization.

min_speaker_count int32

Default value: 2

Defines minimum number of speakers in the conversation.

max_speaker_count int32

Default value: 6

Defines maximum number of speakers in the conversation.

profanity_filter boolean

Enables profanity_filter.

use_enhanced boolean

Enables enhanced transcription, this works for models phone_call and video.

model string

Possible values: [latest_long, latest_short, command_and_search, phone_call, video, default, medical_conversation, medical_dictation]

The model to use for transcription.

hints string[]

Default value: ``

Hints to improve transcription accuracy.

speech_context

object[]

Speech context to improve transcription accuracy.

Array [

phrases string[]

Default value: ``

boost number

Possible values: <= 20

Default value: 1

Boost factor for the speech context.

]

Speech context to improve transcription accuracy.

language Telnyx transcription engine list of languages (string)

Possible values: [en, zh, de, es, ru, ko, fr, ja, pt, tr, pl, ca, nl, ar, sv, it, id, hi, fi, vi, he, uk, el, ms, cs, ro, da, hu, ta, no, th, ur, hr, bg, lt, la, mi, ml, cy, sk, te, fa, lv, bn, sr, az, sl, kn, et, mk, br, eu, is, hy, ne, mn, bs, kk, sq, sw, gl, mr, pa, si, km, sn, yo, so, af, oc, ka, be, tg, sd, gu, am, yi, lo, uz, fo, ht, ps, tk, nn, mt, sa, lb, my, bo, tl, mg, as, tt, haw, ln, ha, ba, jw, su, auto_detect]

Default value: en

Language to use for speech recognition

transcription_model string

Possible values: [openai/whisper-tiny, openai/whisper-large-v3-turbo]

Default value: openai/whisper-tiny

The model to use for transcription.

client_state string

Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string.

transcription_tracks string

Default value: inbound

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. Will default to inbound.

command_id string

Use this field to avoid duplicate commands. Telnyx will ignore any command with the same command_id for the same call_control_id.

200: Successful response upon making a call control command.

application/json

• Schema
• Example (from schema)

Schema

data

object

result string

{
  "data": {
    "result": "ok"
  }
}

default: Unexpected error

application/json

• Schema
• Example (from schema)

Schema

errors

Error[]

Array [

code integerrequired

title stringrequired

detail string

source

object

pointer json-pointer

JSON pointer (RFC6901) to the offending entity.

parameter string

Indicates which query parameter caused the error.

meta object

]

{
  "errors": [
    {
      "code": "string",
      "title": "string",
      "detail": "string",
      "source": {
        "pointer": "string",
        "parameter": "string"
      },
      "meta": {}
    }
  ]
}

Request samples

• cURL

---

curl -L 'https://api.telnyx.com/v2/calls/:call_control_id/actions/transcription_start' \
-H 'Content-Type: application/json' \
-H 'Accept: application/json' \
-H 'Authorization: Bearer <TOKEN>' \
-d '{
  "language": "en",
  "client_state": "aGF2ZSBhIG5pY2UgZGF5ID1d",
  "command_id": "891510ac-f3e4-11e8-af5b-de00688a4901"
}'

Response samples

• 200
• default

---

{
  "data": {
    "result": "ok"
  }
}

{
  "errors": [
    {
      "code": "string",
      "title": "string",
      "detail": "string",
      "source": {
        "pointer": "string",
        "parameter": "string"
      },
      "meta": {}
    }
  ]
}