> ## 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). | | `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. |