--- url: >- https://adk.nht.io/api/@nhtio/adk/batteries/interfaces/TransformersJsSttAdapterOptions.md description: Constructor options for the transformers.js STT adapter. --- # Interface: TransformersJsSttAdapterOptions Defined in: [src/batteries/specialists/stt/transformers\_js/types.ts:105](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L105) Constructor options for the transformers.js STT adapter. ## Remarks `model` is required — no default, since Whisper-family models are multi-hundred-megabyte downloads and this battery never triggers one silently (the loud-config rule shared with every on-device battery). ## Extends * [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md) ## Properties | Property | Type | Description | Inherited from | Defined in | | ------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `chunkLengthS?` | `number` | The length of audio chunks to process, in seconds, forwarded to the pipeline call. Default `30`. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:120](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L120) | | `createPipeline?` | [`CreateTransformersJsSttPipeline`](../type-aliases/CreateTransformersJsSttPipeline.md) | Override the pipeline factory. Default: `pipeline('automatic-speech-recognition', …)` via dynamic import. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:114](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L114) | | `decodeAudio?` | [`DecodeAudioFn`](../specialists/_shared/type-aliases/DecodeAudioFn.md) | Override the audio-decode step (encoded container bytes → mono PCM). Default: [@nhtio/adk/batteries/specialists/\_shared!defaultDecodeAudio](../specialists/_shared/variables/defaultDecodeAudio.md). | - | [src/batteries/specialists/stt/transformers\_js/types.ts:125](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L125) | | `device?` | | `"auto"` | `"gpu"` | `"cpu"` | `"wasm"` | `"webgpu"` | `"cuda"` | `"dml"` | `"coreml"` | `"webnn"` | `"webnn-npu"` | `"webnn-gpu"` | `"webnn-cpu"` | Inference device forwarded to `pipeline()`. Default: transformers.js environment default. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:116](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L116) | | `dtype?` | | `"auto"` | `"fp32"` | `"fp16"` | `"q8"` | `"int8"` | `"uint8"` | `"q4"` | `"bnb4"` | `"q4f16"` | `"q2"` | `"q2f16"` | `"q1"` | `"q1f16"` | Quantization/precision dtype forwarded to `pipeline()`. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:118](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L118) | | `isAvailable?` | () => `boolean` | Override the availability probe. Default: `true` whenever the peer is importable (env-neutral). | - | [src/batteries/specialists/stt/transformers\_js/types.ts:135](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L135) | | `model` | `string` | The Whisper (or compatible) ASR model id, e.g. `onnx-community/whisper-base`. Required. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:107](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L107) | | `modelSource?` | [`TransformersJsSttModelSource`](../type-aliases/TransformersJsSttModelSource.md) | Custom model-source resolver (OPFS / separate source / bundled bytes). When set, model files load through it behind the global-`env` mutex; otherwise straight from HF (unchanged). See [TransformersJsSttModelSource](../type-aliases/TransformersJsSttModelSource.md). | - | [src/batteries/specialists/stt/transformers\_js/types.ts:131](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L131) | | `onCompiling?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | Engine/graph/shader compilation after download, before the first token. A COARSE marker: the on-device runtimes (LiteRT `Engine.create`, transformers.js `from_pretrained`) expose the boundary — download done, opaque WebGPU/WASM graph build about to run — but NOT a progress stream, so `progress` is usually absent. Often the slowest part of a cold start; without this it was invisible. | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onCompiling`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-oncompiling) | [src/batteries/llm/chat\_common/lifecycle.ts:89](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L89) | | `onComplete?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | After the turn's output is parsed + persisted, before `ack` (fires per turn). | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onComplete`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-oncomplete) | [src/batteries/llm/chat\_common/lifecycle.ts:95](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L95) | | `onError?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | A load or generation failure (paired with `nack`). | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onError`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-onerror) | [src/batteries/llm/chat\_common/lifecycle.ts:97](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L97) | | `onGenerating?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | Immediately before the provider generate call (fires per turn). | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onGenerating`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-ongenerating) | [src/batteries/llm/chat\_common/lifecycle.ts:93](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L93) | | `onInitProgress?` | `ProgressCallback` | Called with model-load progress reports while weights download/compile. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:133](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L133) | | `onLifecycle?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | Fires on EVERY phase transition (the firehose). | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onLifecycle`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-onlifecycle) | [src/batteries/llm/chat\_common/lifecycle.ts:80](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L80) | | `onLoading?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | Weights/runtime loading — may fire repeatedly with `progress` as the provider reports it. | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onLoading`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-onloading) | [src/batteries/llm/chat\_common/lifecycle.ts:82](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L82) | | `onReady?` | [`BatteryLifecycleCallback`](../llm/transformers_js/helpers/type-aliases/BatteryLifecycleCallback.md) | Engine/pipeline resolved and cached, before the first generation. | [`BatteryLifecycleHooks`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md).[`onReady`](../llm/transformers_js/helpers/interfaces/BatteryLifecycleHooks.md#property-onready) | [src/batteries/llm/chat\_common/lifecycle.ts:91](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/llm/chat_common/lifecycle.ts#L91) | | `pipeline?` | `AutomaticSpeechRecognitionPipeline` | A pre-built pipeline. When provided, the battery uses it directly and skips lazy creation. | - | [src/batteries/specialists/stt/transformers\_js/types.ts:109](https://github.com/NHTIO/ADK/blob/v1.20260713.1/src/src/batteries/specialists/stt/transformers_js/types.ts#L109) |