Pulse STT

European streaming languages tagged Beta. The 7 European codes on the streaming endpoint (de, es, ru, it, fr, nl, pt) now carry a Beta badge on the Pulse model card.

Pre-recorded language list trimmed. Removed da, lv, et, mt from the batch language table (not offered on batch). New counts: 22 pre-recorded, 31 total, 21 streaming unchanged. multi-eu aggregator now covers 17 European codes and is pre-recorded only.

Documentation refresh for the streaming keywords query parameter.

Session limit raised to 10,000 keywords (from 100).

Intensifier guidance rewritten. Default is 1.0. Recommended tuning range is 1 to 3. Values above 5 push the model into hallucination and repetition; keep keywords at 1 and only raise a specific one if it is still being missed.

Small STT docs corrections surfaced by customer reports and post-#251 audit.

multi-indic restored on pre-recorded. Documented as a pre-recorded aggregator (India region only) covering en, hi, gu, mr, bn, or. Streaming still uses north_indic for the same coverage; multi-indic is not supported on the streaming endpoint. Aligns the docs with what the platform actually accepts on POST /waves/v1/stt/.

Pulse STT streaming finalizes each turn on trailing silence by default. When the speaker stops, the server emits is_final: true promptly instead of waiting for the model’s internal finalization cadence. Transcript accuracy is unchanged.

To restore the previous finalization behavior, set endpointing=false on the WebSocket URL:

Tamil, Telugu, Kannada, and Malayalam (plus the multi-south-indic aggregator) are now marked Beta on the Pulse model card and the STT overview. Accuracy improvements are ongoing. These codes remain India-region only (wss://api.smallest.ai/waves/v1/stt/live); the US endpoint continues to reject them with LANGUAGE_NOT_ENABLED_IN_REGION.

Also cleaned up stale multi (bare) language references in the pulse-stt-ws-overrides.yml enum, the pulse-stt API reference, and the voice-cloning-openapi.yaml language example. multi was replaced by the current multi-eu / multi-asian / north_indic / multi-south-indic aggregators when the streaming enum was revised. Pre-recorded aggregators (multi-eu, multi-asian) are unchanged.

The per-word confidence score is now documented across the Speech-to-Text API reference. These fields were already returned by the API — this makes them explicit in the reference.

• Sync REST (POST /waves/v1/stt): the words[] entries (returned when word_timestamps=true) carry word, start, end, and a confidence score from 0.0 to 1.0. The confidence field is now described in the Word schema, and the word_timestamps parameter documents the full per-word shape it surfaces.
• Streaming (WSS /waves/v1/stt/live): the words[] schema now lists confidence, plus speaker_confidence (returned alongside speaker when diarize=true).

The Pulse streaming Speech-to-Text API now supports four South Indian languages: Tamil (ta), Telugu (te), Kannada (kn), and Malayalam (ml). The multi-south-indic aggregator is also available for unknown South Indian audio — it auto-detects across the same four-language set plus English code-switching.

These five language values are served from the India region only — connect to wss://api.smallest.ai/waves/v1/stt/live?model=pulse (or the legacy wss://api.smallest.ai/waves/v1/pulse/get_text). Requesting any of them on the US host (wss://api.us.smallest.ai/...) returns an error:

The Pulse streaming Speech-to-Text API now supports four Asian languages: Japanese (ja), Cantonese (yue), Mandarin (zh), and Korean (ko). The multi-asian aggregator is also available for unknown East Asian audio — it auto-detects across the same four-language set.

These five language values are served from the US region only — connect to wss://api.us.smallest.ai/waves/v1/stt/live?model=pulse (or the legacy wss://api.us.smallest.ai/waves/v1/pulse/get_text) instead of the default wss://api.smallest.ai/... host. Requesting any of them on the default (ap-south-1) host closes the connection without a transcription frame.

The Pulse STT supported-languages story is now consistent end-to-end. Each surface labels its mode and points readers at the right neighbour:

• Overview page (/models/documentation/speech-to-text-pulse/overview): split the single Supported Languages table into two — Streaming (Real-Time, WebSocket) and Non-Streaming (Pre-Recorded, HTTP). Same 39-language set in both, matching the Pulse model card.
• API Reference — Pre-Recorded (HTTP): language query param now declares an explicit enum of 39 single-language codes (en, hi, es, …) plus multi-eu / multi-indic aggregators. Description labels the endpoint as Pre-Recorded and points at the streaming WebSocket endpoint for the live mode.
• API Reference — Streaming (WebSocket): same enum and labelling, applied via the AsyncAPI override so it renders correctly. The page-top Note labels it as Streaming and points at the HTTP endpoint for pre-recorded.

The Pulse STT WebSocket API reference now correctly renders both control-message operations on docs.smallest.ai:

• sendFinalize — payload {"type":"finalize"} — flushes the current audio buffer and emits an is_final: true transcript while keeping the session open. Useful for per-turn finalization in agentic pipelines.
• sendCloseStream — payload {"type":"close_stream"} — flushes any buffered audio, emits the terminal is_final: true + is_last: true transcript, then closes the session.

The unified Speech-to-Text WebSocket API reference page now documents both control messages with their correct semantics:

• sendFinalize — turn-boundary signal. Flushes the current audio buffer, runs ITN, and emits one is_final: true transcript for that turn. The WebSocket stays open for the next user turn. Use this once per turn in any multi-turn flow.
• sendClose — session-end signal. Flushes remaining audio, emits the terminal is_final: true + is_last: true transcript, then closes the WebSocket. Use this once at the end of the session.

The Speech-to-Text API now lives at the unified path /waves/v1/stt/, mirroring the unified TTS shape. The model is selected via the ?model= query parameter. Two models are live today:

• ?model=pulse: multilingual (17 streaming + 26 pre-recorded languages), HTTP + WebSocket streaming.
• ?model=pulse-pro: leaderboard-ranked English STT (5.42% ESB avg WER, tied #2 on the public Open ASR Leaderboard). HTTP only.

The full Pulse STT feature set is now available on both HTTP (pre-recorded) and WebSocket (realtime) modes with consistent flag names and response shapes.

What this means in practice:

• Same query parameters and request body fields work the same way on POST /waves/v1/pulse/get_text (pre-recorded) and wss://api.smallest.ai/waves/v1/pulse/get_text (realtime).
• Speaker diarization, word timestamps, sentence-level utterances, emotion detection, gender detection, keyword boosting, redaction, punctuation, and inverse text normalisation all behave identically across modes.
• The full per-feature documentation is on the Features pages.

The legacy numerals query parameter on the Pulse STT WebSocket has been removed from the API reference, navigation, and feature pages. The 2026-05-06 deprecation note on this changelog feed flagged this for two weeks; today’s clean-up drops it from the documented surface area.

What changed in the docs

• numerals removed from the Pulse WS AsyncAPI spec + v4 override.
• The “Numeric formatting” feature page and its nav entry are gone.
• The “Convert numerals” cards on realtime/features.mdx and pre-recorded/features.mdx are gone.
• The ITN feature page no longer lists numerals in its precedence table.

The pre-recorded REST endpoint (POST /waves/v1/pulse/get_text) now lists the encoding query parameter alongside the streaming WebSocket. Same 6-value enum: linear16, linear32, alaw, mulaw, opus, ogg_opus. Default is linear16.

When omitted, the server falls back to detecting the format from the file’s container header (works for .wav, .mp3, .flac, .ogg, .m4a, .webm).

The age_detection query parameter and the corresponding top-level age field in the response have been removed from the Pulse STT pre-recorded HTTP API (POST /waves/v1/pulse/get_text). Gender detection (gender_detection / gender) and emotion detection (emotion_detection / emotions) are unaffected.

Specs and reference docs updated:

The numerals query parameter on the Pulse STT WebSocket API still works and continues to behave as documented. For new integrations we now recommend itn_normalize=true instead — it covers digits as well as dates, currencies, phone numbers, and other spoken-form entities, and gives more consistent results across languages.

Existing code that uses numerals does not need to change.

The pre-rename AsyncAPI spec for wss://api.smallest.ai/waves/v1/asr has been removed. This is the final piece of the legacy STT WebSocket cleanup. Pulse STT (wss://api.smallest.ai/waves/v1/pulse/get_text) has been the supported real-time STT surface throughout; the older channel was already unlinked from the v4 API reference navigation and was kept only for historical SDK generation.

The Pulse STT Performance page (/models/documentation/speech-to-text-pulse/benchmarks/performance) now reflects the canonical benchmark comparison across four datasets:

• FLEURS — pre-recorded (29 languages)
• FLEURS — streaming (8 languages)
• ESB — streaming (9 English domains)
• WildASR — streaming (8 robustness conditions)
• Internal English perturbation suite (12 categories)

The legacy WebSocket reference at wss://api.smallest.ai/waves/v1/lightning/get_text has been removed from the docs. Pulse STT (wss://api.smallest.ai/waves/v1/pulse/get_text) is the supported real-time STT surface; the legacy endpoint was already unlinked from the v4 API reference navigation and was only kept for historical reference.

Files removed: