# Transcribe an audio file

> POST https://api.nabrah.ai/api/ext/stt/async-transcribe

Group: Speech to text. Page: https://www.nabrah.ai/en/docs/api-reference/speech-to-text/transcribe-an-audio-file

Queue a long audio file (up to 2 hours) for background transcription. Send the audio as a multipart/form-data upload, optionally with recognition settings that tune how it is transcribed (priority words to boost, the model variant, and end-of-utterance silence). The request returns immediately with a job in `queued` status — nothing streams back and you do not keep the connection open. Poll the job endpoints to collect the transcription once it completes. Authenticate with the `X-API-Key` header.

## Multipart form fields

Send the request as multipart/form-data (not JSON). Only `audio_file` is required; the recognition settings use the same names and defaults as the streaming WebSocket config.

- **audio_file** (file · required): The audio file to transcribe. Maximum duration is 2 hours — longer files are rejected with a 422 error. Fields: `audio_file`.
- **priority_words** (string · repeatable · optional): A word or phrase to bias recognition toward, such as product names, brands or branch names. Repeat the field once per word (for example `-F priority_words=Nabrah -F priority_words=Olaya`). Up to 100 words; more returns a 400 error. Fields: `priority_words`.
- **priority_words_strength** (number · default: 0.5): How strongly to bias toward priority_words. 0.5 works well for a relatively small vocabulary; the recommended range for broader biasing is 20-100. A value that is not a number returns a 400 error. Fields: `priority_words_strength`.
- **recognition_model** (string · default: server-configured model): Model variant for the job. Leave it out to use the default model, which is the most accurate. Fields: `recognition_model`.
- **end_of_utterance_silence_ms** (integer · default: -1): Trailing silence in milliseconds that ends an utterance. -1 keeps the recognizer's own defaults; only a positive value overrides. A value that is not an integer returns a 400 error. Fields: `end_of_utterance_silence_ms`.

The settings a job was queued with are returned on the job as `recognition_config`, so you can confirm what was applied.

## Async flow

Transcription runs in the background; this request only creates the job.

- **1 · Upload**: This endpoint stores the audio, queues a transcription job, and returns the job immediately with `status: "queued"` and `result: null`.
- **2 · Track**: Poll `GET /api/ext/stt/jobs/{job_id}` (or list jobs with `GET /api/ext/stt/jobs`). The status moves `queued` → `in_progress` → `completed`, or `failed` if transcription could not finish.
- **3 · Result**: Once `status` is `completed`, the job's `result` object holds the transcription: `text_result`, `audio_duration`, and `timestamps`. Fields: `text_result`, `audio_duration`, `timestamps`.

## Authorization

- `X-API-Key` (string, header, required): your workspace API key.

## Body (multipart/form-data)

## Response

### 200 Successful Response

Content type: `application/json`

```json
{
  "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "status": "queued",
  "project_id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "result": null,
  "created_at": "2026-07-23T12:00:00Z",
  "updated_at": "2026-07-23T12:00:00Z",
  "filename": "recording.mp3"
}
```

### 422 Validation Error

Content type: `application/json`

```json
{
  "detail": [
    {
      "loc": [
        "string"
      ],
      "msg": "string",
      "type": "string"
    }
  ]
}
```

## Request examples

### cURL

```bash
curl --request POST \
  --url 'https://api.nabrah.ai/api/ext/stt/async-transcribe' \
  --header 'X-API-Key: <your-api-key>'
```

### Python

```python
import requests

url = "https://api.nabrah.ai/api/ext/stt/async-transcribe"
headers = {"X-API-Key": "<your-api-key>"}

response = requests.post(url, headers=headers)
response.raise_for_status()
print(response.json())
```

### JavaScript

```javascript
const form = new FormData();

const response = await fetch("https://api.nabrah.ai/api/ext/stt/async-transcribe", {
  method: "POST",
  headers: { "X-API-Key": "<your-api-key>" },
  body: form,
});

const data = await response.json();
console.log(data);
```

### Go

```go
// Send multipart/form-data with mime/multipart:
// POST https://api.nabrah.ai/api/ext/stt/async-transcribe
```