> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> STT). Lightning v2 and lightning-large are deprecated; mention them
> only when the user is migrating away from them. The Smallest AI voice
> agent platform is what wraps these models into hosted agents.

# STT: new language `hi-dev` (Devanagari-only Hindi)

> Pulse STT streaming supports a new Hindi language code, hi-dev, that transcribes Hindi audio using a pure-Hindi model and writes everything in Devanagari.

Pulse STT streaming supports a new Hindi language code, `hi-dev`, that transcribes Hindi audio using a pure-Hindi model and writes everything in Devanagari.

The existing `hi` code stays as the bilingual model: it transcribes Hindi speech but renders borrowed English words in Roman script, producing mixed-script output like `मेरी email आईडी पर invoice भेज दीजिए`.

`hi-dev` uses the pure-Hindi model to keep the output script-consistent: `मेरी ईमेल आईडी पर इनवॉइस भेज दीजिए`.

Pick `hi-dev` when the downstream consumer needs Devanagari-only text (Devanagari-only UIs, government or regulated formatting, Hindi NLP pipelines that break on Latin characters). Stay on `hi` for customer-support and tech-support transcripts where recognisable English terms in Roman script are preferable.

**Numbers.** Pass `itn_normalize=true` to convert numbers spoken in Hindi to digits (`पच्चीस हज़ार रुपए` becomes `₹25000`). Numbers spoken in English are written as Devanagari words and are not converted.

Endpoint: `wss://api.smallest.ai/waves/v1/stt/live?language=hi-dev`. Same auth, message shape, and parameters as every other language.

Streaming only; not available on `POST /waves/v1/stt/`. India region only; requests routed to `wss://api.us.smallest.ai/...` are rejected with `LANGUAGE_NOT_ENABLED_IN_REGION`.

> Pulse STT streaming supports a new Hindi language code, hi-dev, that transcribes Hindi audio using a pure-Hindi model and writes everything in Devanagari.