# Stable Audio 3 Small Music Base Audio Outpainting API

> Outpainting du point de contrôle de base Small music : poursuit une piste à l’une ou l’autre extrémité, 50 étapes par défaut

Prolonge un clip musical fourni via `audio_url` à l’aide d’un `prompt` texte. `extend_seconds_before` et `extend_seconds_after` acceptent chacun de 0 à 120 secondes de nouvel audio. Il s’agit du point de contrôle de base : il utilise donc par défaut 50 étapes d’échantillonnage et une échelle de guidage de 7, avec un guidage réglable jusqu’à 25. Les formats de sortie comprennent mp3, wav et flac.

- Model id: `stable-audio-3/small/music/base/audio-outpainting`
- Made by: Stability AI
- Category: Text to Music
- Output: audio
- Price: $0.0339 / request (cheapest run $0.034 (34 API credits))
- Run: `POST https://api.doitong.ru/v1/run/stable-audio-3/small/music/base/audio-outpainting`
- Quote: `POST https://api.doitong.ru/v1/quote/stable-audio-3/small/music/base/audio-outpainting`
- Docs page: https://doitong.com/fr/developers/models/stable-audio-3/small/music/base/audio-outpainting

## Pricing

Price: **$0.0339 / request**. Billed once per request.

The full example input below costs $0.034 = 34 API credits (1 request × 33.9 API credits).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.ru/v1/quote/stable-audio-3/small/music/base/audio-outpainting` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `negative_prompt` |  | string | no | `` |  | Texte spécifiant les qualités indésirables dans la sortie. |
| `num_inference_steps` |  | integer | no | `50` | 1 – 100 | Choisissez le nombre d’étapes d’échantillonnage à exécuter ; environ 50 permettent d’obtenir une bonne qualité avec des points de contrôle de base (non distillés). |
| `guidance_scale` |  | number | no | `7` | 0 – 25 | Force du guidage sans classifieur ; une valeur d’environ 7.0 est initialement recommandée pour les points de contrôle de base. L’augmenter rapproche la génération du prompt. |
| `seed` |  | integer \| null | no |  |  | Graine du générateur aléatoire pour obtenir des résultats reproductibles ; l’omettre sélectionne une graine aléatoire. |
| `enable_prompt_expansion` |  | boolean | no | `false` |  | Extension du prompt par un LLM lorsqu’elle est activée, ajoutant des détails et améliorant la qualité du résultat. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Vérification de sécurité du contenu NSFW. |
| `output_format` |  | enum (string) | no | `mp3` | `mp3`, `wav`, `flac`, `ogg`, `opus`, `m4a`, `aac` | Format de conteneur utilisé pour l’audio obtenu. |
| `bitrate` |  | string | no | `192k` |  | Débit audio de sortie, ignoré avec wav ou flac car ces formats sont sans perte. Pour les formats compressés tels que mp3, aac ou opus, fournissez une valeur sous la forme '192k' ou '320k'. |
| `prompt` |  | string | yes |  |  | Instructions textuelles décrivant le contenu de l’extension. |
| `audio_url` | `audio` | string (audio URL) | yes |  |  | Audio d’entrée pour l’extension. |
| `extend_seconds_before` |  | number | no | `0` | 0 – 120 | Durée, en secondes, de l’audio nouvellement généré ajouté avant la source. |
| `extend_seconds_after` |  | number | no | `0` | 0 – 120 | Durée, en secondes, de l’audio nouvellement généré ajouté après la source. |

File parameters (`audio`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "audio": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.ru/v1/run/stable-audio-3/small/music/base/audio-outpainting?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.ru/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.ru/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/stable-audio-3/small/music/base/audio-outpainting?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.ru/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/stable-audio-3/small/music/base/audio-outpainting", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.ru/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "stable-audio-3/small/music/base/audio-outpainting",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "stable-audio-3/small/music/base/audio-outpainting",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 34,
    "usd": "0.034",
    "charged": 34,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  },
  "output": {
    "audio": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
      "content_type": "audio/mpeg",
      "file_name": "0-output.mp3",
      "file_size": 1843200
    },
    "seed": 42,
    "prompt": "string"
  },
  "outputs": [
    {
      "type": "audio",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
      "content_type": "audio/mpeg",
      "file_size": 1843200,
      "duration": 12,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `audio` | object {url, content_type, file_name, file_size} | Clip audio produit par la génération. |
| `seed` | integer | Graine contrôlant l’aléatoire pendant la génération. |
| `prompt` | string | Prompt utilisé pour générer la sortie. |

## Related models

- [Stable Audio 3 Small Music Audio Inpainting](https://doitong.com/developers/models/stable-audio-3/small/music/audio-inpainting.md) (`stable-audio-3/small/music/audio-inpainting`): $0.026 / request
- [Stable Audio 3 Small Music Audio Outpainting](https://doitong.com/developers/models/stable-audio-3/small/music/audio-outpainting.md) (`stable-audio-3/small/music/audio-outpainting`): $0.0265 / request
- [Stable Audio 3 Small Music Base Audio Inpainting](https://doitong.com/developers/models/stable-audio-3/small/music/base/audio-inpainting.md) (`stable-audio-3/small/music/base/audio-inpainting`): $0.0333 / request
- [Stable Audio 3 Small Music Base Audio to Audio](https://doitong.com/developers/models/stable-audio-3/small/music/base/audio-to-audio.md) (`stable-audio-3/small/music/base/audio-to-audio`): $0.032 / request
- [Stable Audio 3 Small Music Text to Audio](https://doitong.com/developers/models/stable-audio-3/small/music/text-to-audio.md) (`stable-audio-3/small/music/text-to-audio`): $0.0217 / request
- [Stable Audio 3 · Small · Music · Audio to Audio](https://doitong.com/developers/models/stable-audio-3/small/music/audio-to-audio.md) (`stable-audio-3/small/music/audio-to-audio`): $0.0248 / request
- [Stable Audio 3 · Small · Music · Base · Text to Audio](https://doitong.com/developers/models/stable-audio-3/small/music/base/text-to-audio.md) (`stable-audio-3/small/music/base/text-to-audio`): $0.0281 / request
- [Stable Audio 3 Medium Audio Inpainting](https://doitong.com/developers/models/stable-audio-3/medium/audio-inpainting.md) (`stable-audio-3/medium/audio-inpainting`): $0.0442 / request

## Links

- HTML page: https://doitong.com/developers/models/stable-audio-3/small/music/base/audio-outpainting
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=stable-audio-3/small/music/base/audio-outpainting
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/stable-audio-3/small/music/base/audio-outpainting