> ## 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.

# CreateAudioTranscriptionsMultipartRequest

## Fields

| Field | Type | Required | Description |
| - | - | - | - |
| `File` | [operations.CreateAudioTranscriptionsMultipartFile](../../models/operations/createaudiotranscriptionsmultipartfile.mdx) | :heavy\_check\_mark: | The audio file to transcribe. The format is derived from the filename extension or the file part content type. Max 25 MB; send larger files as base64 JSON via input\_audio. |
| `Language` | `*string` | :heavy\_minus\_sign: | The language of the input audio (ISO-639-1). |
| `Model` | `string` | :heavy\_check\_mark: | The model to use for transcription. |
| `ResponseFormat` | [\*operations.ResponseFormat](../../models/operations/responseformat.mdx) | :heavy\_minus\_sign: | The response format. "json" (default) returns \{ text, usage }; "verbose\_json" additionally returns task, language, duration, and segment-level timestamps (OpenAI-compatible providers only). |
| `SessionID` | `*string` | :heavy\_minus\_sign: | A unique identifier for grouping related requests (e.g., a conversation or agent workflow). Used for observability grouping in Broadcast and private logging; never sent to the provider. If provided in both the request body and the x-session-id header, the body value takes precedence. |
| `Temperature` | `*float64` | :heavy\_minus\_sign: | The sampling temperature. |
| `TimestampGranularities` | \[][operations.TimestampGranularities](../../models/operations/timestampgranularities.mdx) | :heavy\_minus\_sign: | Timestamp detail levels to include when response\_format is "verbose\_json". "word" additionally returns word-level timestamps in the words array. |
| `Trace` | `*string` | :heavy\_minus\_sign: | JSON-encoded trace metadata object (trace\_id, trace\_name, span\_name, generation\_name, parent\_span\_id and custom keys) attached to the Broadcast trace. Must decode to a JSON object. |
| `User` | `*string` | :heavy\_minus\_sign: | A unique identifier representing your end-user. Forwarded to Broadcast and private logging as the end-user id; never sent to the provider. |