> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# SpeechRequest

Text-to-speech request input

## Fields

| Field            | Type                                                                                                | Required             | Description                                                                                                   | Example                         |
| ---------------- | --------------------------------------------------------------------------------------------------- | -------------------- | ------------------------------------------------------------------------------------------------------------- | ------------------------------- |
| `Input`          | `string`                                                                                            | :heavy\_check\_mark: | Text to synthesize                                                                                            | Hello world                     |
| `Model`          | `string`                                                                                            | :heavy\_check\_mark: | TTS model identifier                                                                                          | mistralai/voxtral-mini-tts-2603 |
| `Provider`       | [\*components.SpeechRequestProvider](../../models/components/speechrequestprovider.mdx)             | :heavy\_minus\_sign: | Provider-specific passthrough configuration                                                                   |                                 |
| `ResponseFormat` | [\*components.SpeechRequestResponseFormat](../../models/components/speechrequestresponseformat.mdx) | :heavy\_minus\_sign: | Audio output format                                                                                           | pcm                             |
| `Speed`          | `*float64`                                                                                          | :heavy\_minus\_sign: | Playback speed multiplier. Only used by models that support it (e.g. OpenAI TTS). Ignored by other providers. | 1                               |
| `Voice`          | `*string`                                                                                           | :heavy\_minus\_sign: | Voice identifier (provider-specific).                                                                         | en\_paul\_neutral               |