transcription_engine and model query parameters.
Engines
| Engine | Default model | Other models | Notes |
|---|---|---|---|
| Deepgram | nova-3 | nova-2, flux | Default engine. Broadest format support. |
| Telnyx | openai/whisper-tiny | — | On-network, lightweight |
latest_long | — | Multilingual, long-form | |
| Azure | azure/fast | — | Broad language/accent coverage |
| xAI | xai/grok-stt | — | Grok STT for real-time transcription |
| AssemblyAI | assemblyai/universal-streaming | — | Universal-Streaming for low-latency voice agents |
| Speechmatics | speechmatics/standard | — | High-accuracy real-time transcription with multilingual and bilingual packs |
| Soniox | soniox/stt-rt-v4 | — | Real-time transcription with automatic language detection |