# Stable Audio 3 Medium Audio to Audio API

> Destilléiert Stable Audio 3 Medium, dat e Quellclip aus engem Prompt an eng nei Variant remixt

Transforméiert `audio_url` no engem `prompt` a produzéiert Audio mat enger `duration` vun 1 bis 380 Sekonnen (Standard 30). `init_noise_level` vun 0 bis 1 setzt, wéi no d'Resultat der Quell follegt: e niddrege Wäert hält et no bei der Quell, 1.0 generéiert komplett nei. Standard si 8 Schrëtt; verschidden Output-Formater si verfügbar.

- Model id: `stable-audio-3/medium/audio-to-audio`
- Made by: Stability AI
- Category: Audio
- Output: audio
- Price: $0.0417 / request (cheapest run $0.042 (42 API credits))
- Run: `POST https://api.doitong.com/v1/run/stable-audio-3/medium/audio-to-audio`
- Quote: `POST https://api.doitong.com/v1/quote/stable-audio-3/medium/audio-to-audio`
- Docs page: https://doitong.com/lb/developers/models/stable-audio-3/medium/audio-to-audio

## Pricing

Price: **$0.0417 / request**. Billed once per request.

The full example input below costs $0.042 = 42 API credits (1 request × 41.7 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.com/v1/quote/stable-audio-3/medium/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 | `` |  | Text, deen onerwënscht Qualitéiten am Output ugëtt. |
| `duration` |  | number | no | `30` | 1 – 380 | Audio-Längt a Sekonnen, mat engem Maximum vu 380 Sekonnen beim Medium-Modell (ongeféier 6 Minutten 20 Sekonnen). |
| `num_inference_steps` |  | integer | no | `8` | 1 – 100 | Zuel vun de Sampling-Iteratiounen, standardméisseg 8, well distilléiert a post-trainéiert Checkpoints do schonn eng gutt Qualitéit erreechen; zousätzlech Iteratioune brénge wéineg Virdeel. |
| `guidance_scale` |  | number | no | `1` | 0 – 25 | Classifier-free-Guidance-Stäerkt nëmme fir Basis-Checkpoints; distilléiert Checkpoints si dovun net betraff. Bei passenden Checkpoints verstäerkt eng Erhéijung d'Befollegung vum Prompt. |
| `seed` |  | integer \| null | no |  |  | Seed vum Zoufallsgenerator fir widderhuelbar Resultater; wann e feelt, gëtt e zoufällege Seed ausgewielt. |
| `enable_prompt_expansion` |  | boolean | no | `false` |  | Prompt-Erweiderung mat engem LLM, wann aktivéiert, fir Detailer bäizefügen an d'Resultatqualitéit ze verbesseren. |
| `enable_safety_checker` |  | boolean | no | `true` |  | Sécherheetskontroll op NSFW-Inhalter. |
| `output_format` |  | enum (string) | no | `mp3` | `mp3`, `wav`, `flac`, `ogg`, `opus`, `m4a`, `aac` | Containerformat vum resultéierenden Audio. |
| `bitrate` |  | string | no | `192k` |  | Bitrate vum Output-Audio, ignoréiert bei wav oder flac, well dës lossless sinn. Fir kompriméiert Formater wéi mp3, aac oder opus gitt e Wäert an der Form '192k' oder '320k' un. |
| `prompt` |  | string | yes |  |  | Textinstruktiounen, déi d'Transformatioun vum Quell-Audio beschreiwen. |
| `audio_url` | `audio` | string (audio URL) | yes |  |  | Input-Audio fir d'Transformatioun. |
| `init_noise_level` |  | number | no | `0.9` | 0 – 1 | Rauschniveau vum Quell-Audio: 0.1 erhält eng grouss Ähnlechkeet zum Input, 0.5 ass mëttel an 1.0 ersetzt d'Quell komplett duerch Rauschen fir eng reng Generatioun. |

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.com/v1/run/stable-audio-3/medium/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.com/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.com/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/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.com/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/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.com/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/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/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": 42,
    "usd": "0.042",
    "charged": 42,
    "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.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `audio` | object {url, content_type, file_name, file_size} | Audio-Clip, deen duerch d'Generatioun erstallt gouf. |
| `seed` | integer | Seed, deen d'Zoufällegkeet während der Generatioun gesteiert huet. |
| `prompt` | string | Prompt, dee fir d'Generatioun vum Output benotzt gouf. |

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