> ## 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.

# STTRequest

Speech-to-text request input. Accepts a JSON body with input\_audio containing base64-encoded audio.

## Fields

| Field                    | Type                                                                                          | Required             | Description                                                                                                                                                                                                                                        | Example                                                    |
| ------------------------ | --------------------------------------------------------------------------------------------- | -------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------- |
| `InputAudio`             | [components.STTInputAudio](../../models/components/sttinputaudio.mdx)                         | :heavy\_check\_mark: | Base64-encoded audio to transcribe                                                                                                                                                                                                                 | \{<br />"data": "UklGRiQA...",<br />"format": "wav"<br />} |
| `Language`               | `*string`                                                                                     | :heavy\_minus\_sign: | ISO-639-1 language code (e.g., "en", "ja"). Auto-detected if omitted.                                                                                                                                                                              | en                                                         |
| `Model`                  | `string`                                                                                      | :heavy\_check\_mark: | STT model identifier                                                                                                                                                                                                                               | openai/whisper-large-v3                                    |
| `Provider`               | [\*components.STTRequestProvider](../../models/components/sttrequestprovider.mdx)             | :heavy\_minus\_sign: | Provider-specific passthrough configuration                                                                                                                                                                                                        |                                                            |
| `ResponseFormat`         | [\*components.STTRequestResponseFormat](../../models/components/sttrequestresponseformat.mdx) | :heavy\_minus\_sign: | Output format. "json" (default) returns \{ text, usage }. "verbose\_json" additionally returns task, language, duration, and segment-level timestamps; only supported by OpenAI-compatible providers.                                              | json                                                       |
| `Temperature`            | `*float64`                                                                                    | :heavy\_minus\_sign: | Sampling temperature for transcription                                                                                                                                                                                                             | 0                                                          |
| `TimestampGranularities` | \[][components.STTTimestampGranularity](../../models/components/stttimestampgranularity.mdx)  | :heavy\_minus\_sign: | Timestamp detail levels to include when response\_format is "verbose\_json". "segment" returns segment-level timestamps; "word" additionally returns word-level timestamps in the words array. Ignored unless response\_format is "verbose\_json". | \[<br />"segment"<br />]                                   |