# Audio Transcriptions API — Speech to text

Source: https://ofox.io/docs/api/openai/audio-transcriptions

Turns audio into text. Compatible with OpenAI's `POST /v1/audio/transcriptions`; upload the audio file as `multipart/form-data`.

| Family | Model | Notes |
|---|---|---|
| GPT transcription | `openai/gpt-transcribe`, `openai/gpt-4o-mini-transcribe`, `openai/gpt-4o-transcribe-diarize` | See [GPT transcription](https://ofox.io/docs/develop/models/gpt-transcribe) |
| ElevenLabs | `elevenlabs/scribe_v2` | Supports word-level timestamps and speaker diarization; see [ElevenLabs](https://ofox.io/docs/develop/models/elevenlabs) |

## Quickstart

- base_url: `https://api.ofox.io/v1`
- Endpoint: `https://api.ofox.io/v1/audio/transcriptions`
- Model ID: `openai/gpt-transcribe`

**Python**

```python filename="transcribe.py"
import os
from openai import OpenAI

client = OpenAI(base_url="https://api.ofox.io/v1", api_key=os.environ["OFOX_API_KEY"])

with open("meeting.mp3", "rb") as f:
    result = client.audio.transcriptions.create(
        model="openai/gpt-transcribe",
        file=f,
        language="zh",
        prompt="以下是普通话的句子，请使用简体中文。",
    )
print(result.text)
```

**cURL**

```bash filename="Terminal"
curl https://api.ofox.io/v1/audio/transcriptions \
  -H "Authorization: Bearer $OFOX_API_KEY" \
  -F model=openai/gpt-transcribe \
  -F language=zh \
  -F prompt="以下是普通话的句子，请使用简体中文。" \
  -F file=@meeting.mp3
```

## Request parameters

**file** `file` · required

The audio file, e.g. `mp3` or `wav`. A non-audio file returns 400.

**model** `string` · required

Model ID; see the table above.

**language** `string`

The language of the audio, e.g. `zh` or `en`. Detected automatically if omitted.

**prompt** `string`

Prompt text for guiding word choice or proper nouns; applies to GPT transcription models. When transcribing Mandarin, pass `language: "zh"` together with the prompt "以下是普通话的句子，请使用简体中文。" ("The following are sentences in Mandarin; please use Simplified Chinese."), otherwise the output may come back in Traditional Chinese characters.

**response_format** `string` · default `json` · values `json` / `verbose_json`

Only `json` and `verbose_json` are supported; `text`, `srt` and `vtt` return 400. `verbose_json` applies only to ElevenLabs Scribe.

**provider_options** `string`

Provider-specific parameters, sent as a JSON string in a form field, e.g. `{"elevenlabs": {"diarize": true}}`. See each family page.

## Response

```json
{
  "text": "今天天气很好，我们下午三点在会议室讨论新功能。",
  "usage": { "type": "duration", "seconds": 9 }
}
```

**text** `string`

The transcribed text.

**usage** `object`

The billing basis. When `type` is `duration`, billing is by audio seconds (`seconds`); when it is `tokens`, billing is by tokens (`input_tokens`, `output_tokens`).

ElevenLabs Scribe also returns `words` (per-word text with start and end times), `language`, `duration` and other fields; see [ElevenLabs](https://ofox.io/docs/develop/models/elevenlabs#scribe). If you need subtitle files, generate them yourself from the timestamps in `words`.

## Common errors
| HTTP | Error message | Cause | Fix |
|---|---|---|---|
| 400 | `Unsupported response_format 'srt'. Only 'json' and 'verbose_json' are supported on this gateway` | `text`, `srt` or `vtt` was used | Use `json`; build subtitles from the timestamps |
| 400 | `response_format 'verbose_json' is not compatible with model 'gpt-transcribe'. Use 'json' or 'text' instead.` | GPT transcription models do not support `verbose_json` | Use `json` |
| 400 | `Unsupported file format txt` | The uploaded file is not audio | Upload audio such as `mp3` or `wav` |
| 400 | `Model 'openai/gpt-5.4' is not supported on /v1/audio/transcriptions. Supported: ...` | The chosen model is not a transcription model | Use one of the models listed in the error |
| 400 | `You must provide a model parameter.` | The request was sent as JSON rather than a form | Upload the file as `multipart/form-data` |

For the full list of error codes, see [Error handling](https://ofox.io/docs/develop/guides/error-handling).