---
title: "Changes to Transcription start"
method: POST
path: "/calls/{call_control_id}/actions/transcription_start"
---

# Changes to Transcription start

`POST /calls/{call_control_id}/actions/transcription_start`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 6 of 89 revisions.

- **2026-10-21** `a2e3f7a0ec7b`: 51 info
- **2026-10-19** `a1c38ee7cad5`: 2 info
- **2026-10-15** `a72569d69430`: 1 breaking, 9 info
- **2026-05-18** `c260e29f1496`: 3 info
- **2026-05-14** `50870cc05614`: 3 info
- **2026-05-08** `30cb1ddce91b`: 4 info

## Changes

- **2026-10-21** `a2e3f7a0ec7b`: 51 info
  - added the new `ar` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `be` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `bg` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `bn` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ca` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `cmn` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `cmn-Hans` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `cmn-Hant` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `cs` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `da` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `de` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `el` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `en-AU` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `en-GB` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `en-US` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `eo` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `es` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `et` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `fa` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `fi` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `fr` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `he` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `hi` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `hr` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `hu` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ia` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `id` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `it` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ja` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ko` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `lt` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `lv` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `mr` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ms` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `nl` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `no` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `pl` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `pt` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ro` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - added the new `ru` enum value to the request property `transcription_engine_config/oneOf[subschema #7: Transcription engine Speechmatics config]/language`
  - …11 more
- **2026-10-19** `a1c38ee7cad5`: 2 info
  - added `deepgram/nova-2-medical, deepgram/nova-2-phonecall, deepgram/nova-3-medical, deepgram/flux, deepgram/flux-multi` discriminator mapping keys to the `transcription_engine_config/oneOf[#/components/schemas/TranscriptionEngineDeepgramConfig]/` request property
  - added `#/components/schemas/DeepgramNova2SpecialtyConfig, #/components/schemas/DeepgramNova3MedicalConfig, #/components/schemas/DeepgramFluxConfig, #/components/schemas/DeepgramFluxMultiConfig` to the `transcription_engine_config/oneOf[#/components/schemas/TranscriptionEngineDeepgramConfig]/` request property `oneOf` list
- **2026-10-15** `a72569d69430`: 1 breaking, 9 info
  - removed `#/components/schemas/DeepgramNova2Config, #/components/schemas/DeepgramNova3Config` from the `transcription_engine_config` request property `oneOf` list
  - the `transcription_model` request property default value changed from `assemblyai/universal-streaming` to `assemblyai/universal-3-5-pro`
  - added `Parakeet, Humain, Reson8, Cohere` discriminator mapping keys to the `transcription_engine_config` request property
  - removed `deepgram/nova-2, deepgram/nova-3` discriminator mapping keys from the `transcription_engine_config` request property
  - added the new `Cohere` enum value to the request property `transcription_engine`
  - added the new `Humain` enum value to the request property `transcription_engine`
  - added the new `Parakeet` enum value to the request property `transcription_engine`
  - added the new `Reson8` enum value to the request property `transcription_engine`
  - added the new `assemblyai/universal-3-5-pro` enum value to the request property `transcription_engine_config/oneOf[subschema #5: Transcription engine AssemblyAI config -> subschema #6: Transcription engine AssemblyAI config]/transcription_model`
  - added `#/components/schemas/TranscriptionEngineDeepgramConfig, #/components/schemas/TranscriptionEngineParakeetConfig, #/components/schemas/TranscriptionEngineHumainConfig, #/components/schemas/TranscriptionEngineReson8Config, #/components/schemas/TranscriptionEngineCohereConfig` to the `transcription_engine_config` request property `oneOf` list
- **2026-05-18** `c260e29f1496`: 3 info
  - added `Soniox` discriminator mapping keys to the `transcription_engine_config` request property
  - added the new `Soniox` enum value to the request property `transcription_engine`
  - added `#/components/schemas/TranscriptionEngineSonioxConfig` to the `transcription_engine_config` request property `oneOf` list
- **2026-05-14** `50870cc05614`: 3 info
  - added `Speechmatics` discriminator mapping keys to the `transcription_engine_config` request property
  - added the new `Speechmatics` enum value to the request property `transcription_engine`
  - added `#/components/schemas/TranscriptionEngineSpeechmaticsConfig` to the `transcription_engine_config` request property `oneOf` list
- **2026-05-08** `30cb1ddce91b`: 4 info
  - added `xAI, AssemblyAI` discriminator mapping keys to the `transcription_engine_config` request property
  - added the new `AssemblyAI` enum value to the request property `transcription_engine`
  - added the new `xAI` enum value to the request property `transcription_engine`
  - added `#/components/schemas/TranscriptionEngineXaiConfig, #/components/schemas/TranscriptionEngineAssemblyaiConfig` to the `transcription_engine_config` request property `oneOf` list

---

[Operation](https://skmtc.dev/team-telnyx/apis/telnyx-api/docs/calls/:call_control_id/actions/transcription_start/post.md) - [API](https://skmtc.dev/team-telnyx/apis/telnyx-api.md) - [Page](https://skmtc.dev/team-telnyx/apis/telnyx-api/changes/calls/:call_control_id/actions/transcription_start/post)