Sinch Voice API: Choosing between v1 and v2
For all new projects, please use Voice API v2. This is especially important for projects involving:

- AI capabilities like Streams and Voice Relay
- Voice campaigns like Batch calling


You should only use the older Voice API v1 if one of the following is a strict requirement:

- The project must be in General Availability (GA).
- The project requires In-App voice or Conferencing (until these features are available in v2).


## TextMessage

#### Payload Schema

- **command** (string, required)
- **text** (string, required)
Transcribed text from the voice channel. This is the speech-to-text output of the incoming audio.
- **sttLanguage** (string, required)
BCP-47 language tag used for speech-to-text transcription of the inbound audio.
- **isCorrection** (boolean, required)
Indicates whether this message corrects a previous transcription.


This occurs when additional speech is detected after a pause, refining the earlier transcription result.