# Stable Audio 3 Medium Base Audio to Audio API

> Remix de áudio para áudio do Medium com checkpoint base: reformula um clipe de origem com um prompt, por até 380 segundos

Recebe um clipe de origem por `audio_url` e um `prompt` de texto, gerando uma versão transformada. `init_noise_level` (0 a 1) define o quanto o resultado segue a entrada, e `duration` aceita de 1 a 380 segundo. Este é o checkpoint não destilado, portanto os padrões são 50 passos de amostragem e escala de orientação 7. A saída pode ser mp3, wav, flac, ogg, opus, m4a ou aac.

- Model id: `stable-audio-3/medium/base/audio-to-audio`
- Made by: Stability AI
- Category: Audio
- Output: audio
- Price: $0.0523 / request (cheapest run $0.053 (53 API credits))
- Run: `POST https://api.doitong.ru/v1/run/stable-audio-3/medium/base/audio-to-audio`
- Quote: `POST https://api.doitong.ru/v1/quote/stable-audio-3/medium/base/audio-to-audio`
- Docs page: https://doitong.com/pt-BR/developers/models/stable-audio-3/medium/base/audio-to-audio

## Pricing

Price: **$0.0523 / request**. Billed once per request.

The full example input below costs $0.053 = 53 API credits (1 request × 52.3 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/medium/base/audio-to-audio` 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 | `` |  | Texto que especifica qualidades indesejadas na saída. |
| `duration` |  | number | no | `30` | 1 – 380 | Duração do áudio em segundos, com máximo de 380 segundos para o modelo médio (aproximadamente 6 minutos e 20 segundos). |
| `num_inference_steps` |  | integer | no | `50` | 1 – 100 | Escolha quantas etapas de amostragem executar; aproximadamente 50 permitem obter boa qualidade ao usar checkpoints base (não destilados). |
| `guidance_scale` |  | number | no | `7` | 0 – 25 | Intensidade de orientação sem classificador, para a qual aproximadamente 7.0 é inicialmente recomendado em checkpoints base; aumentá-la faz a geração aderir mais ao prompt. |
| `seed` |  | integer \| null | no |  |  | Semente do gerador aleatório para resultados reproduzíveis; omiti-la seleciona uma semente aleatória. |
| `enable_prompt_expansion` |  | boolean | no | `false` |  | Expansão do prompt usando um LLM quando ativada, adicionando detalhes e melhorando a qualidade do resultado. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Verificação de segurança para conteúdo NSFW. |
| `output_format` |  | enum (string) | no | `mp3` | `mp3`, `wav`, `flac`, `ogg`, `opus`, `m4a`, `aac` | Formato do contêiner usado para o áudio resultante. |
| `bitrate` |  | string | no | `192k` |  | Taxa de bits do áudio de saída, ignorada ao usar wav ou flac porque são formatos sem perdas. Para formatos compactados como mp3, aac ou opus, forneça um valor no formato '192k' ou '320k'. |
| `prompt` |  | string | yes |  |  | Instruções de texto que descrevem a transformação a aplicar ao áudio de origem. |
| `audio_url` | `audio` | string (audio URL) | yes |  |  | Áudio de entrada para transformação. |
| `init_noise_level` |  | number | no | `0.9` | 0 – 1 | Nível de ruído do áudio de origem: 0.1 mantém grande semelhança com a entrada, 0.5 é intermediário e 1.0 substitui completamente a fonte por ruído para geração pura. |

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/medium/base/audio-to-audio?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/medium/base/audio-to-audio?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/medium/base/audio-to-audio", 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/medium/base/audio-to-audio",
      "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/medium/base/audio-to-audio",
  "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": 53,
    "usd": "0.053",
    "charged": 53,
    "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} | Clipe de áudio produzido pela geração. |
| `seed` | integer | Seed que controlou a aleatoriedade durante a geração. |
| `prompt` | string | Prompt usado para gerar a saída. |

## 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 Outpainting](https://doitong.com/developers/models/stable-audio-3/small/music/base/audio-outpainting.md) (`stable-audio-3/small/music/base/audio-outpainting`): $0.0339 / 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

## Links

- HTML page: https://doitong.com/developers/models/stable-audio-3/medium/base/audio-to-audio
- 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/medium/base/audio-to-audio
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/stable-audio-3/medium/base/audio-to-audio