---
url: >-
  https://adk.nht.io/api/@nhtio/adk/batteries/tts/_shared/interfaces/SynthesizeOptions.md
description: >-
  Per-call options accepted by every engine's `synthesize`. Engine-specific
  per-call option interfaces extend this with their own knobs.
---

# Interface: SynthesizeOptions

Defined in: [src/batteries/tts/\_shared/index.ts:71](https://github.com/NHTIO/ADK/blob/v1.20260718.0/src/src/batteries/tts/_shared/index.ts#L71)

Per-call options accepted by every engine's `synthesize`. Engine-specific per-call option
interfaces extend this with their own knobs.

## Remarks

Both fields override the constructor-level default of the same name for this one call.

## Extended by

* [`TransformersJsSynthesizeOptions`](../../transformers_js/types/interfaces/TransformersJsSynthesizeOptions.md)
* [`NativeSynthesizeOptions`](../../native/types/interfaces/NativeSynthesizeOptions.md)

## Properties

| Property                             | Type     | Description                                                               | Defined in                                                                                                                           |
| ------------------------------------ | -------- | ------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
|  `rate?`   | `number` | Speaking-rate multiplier for this call; overrides the constructor `rate`. | [src/batteries/tts/\_shared/index.ts:75](https://github.com/NHTIO/ADK/blob/v1.20260718.0/src/src/batteries/tts/_shared/index.ts#L75) |
|  `voice?` | `string` | Voice for this call; overrides the constructor `voice`.                   | [src/batteries/tts/\_shared/index.ts:73](https://github.com/NHTIO/ADK/blob/v1.20260718.0/src/src/batteries/tts/_shared/index.ts#L73) |