# ACE Step Audio To Audio API

> Remixe une piste existante ou remplace ses paroles, guidé par les balises d'origine et les nouvelles balises

Part d'un `audio_url` et de ses `original_tags`, puis applique de nouveaux `tags` pour en modifier le style. `edit_mode` vaut soit remix, qui modifie le son global, soit lyrics, qui ne modifie que les paroles chantées. Vous pouvez fournir `original_lyrics` et de nouvelles `lyrics`, ainsi que `original_seed` s'il est connu. Les paramètres d'étapes et de guidage sont les mêmes que pour le reste de la famille.

- Model id: `ace-step/audio-to-audio`
- Made by: ACE Studio
- Category: Text to Music
- Output: audio
- Price per second of your input audio: $0.0002 / second of input audio (cheapest run $0.001 (1 API credit))
- Run: `POST https://api.doitong.com/v1/run/ace-step/audio-to-audio`
- Quote: `POST https://api.doitong.com/v1/quote/ace-step/audio-to-audio`
- Docs page: https://doitong.com/fr/developers/models/ace-step/audio-to-audio

## Pricing

Price: **$0.0002 / second of input audio**. Price per second of your input audio: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $0.002 = 2 API credits (10 s input audio × $0.0002).

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/ace-step/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 |
|---|---|---|---|---|---|---|
| `audio_url` | `audio` | string (audio URL) | yes |  |  | URL du fichier audio pour l'outpainting. |
| `edit_mode` |  | enum (string) | no | `remix` | `lyrics`, `remix` | Mode d'édition : modifier uniquement les paroles ou remixer l'audio. |
| `original_tags` |  | string | yes |  |  | Balises associées à l'origine au fichier audio. |
| `original_lyrics` |  | string | no | `` |  | Paroles associées à l'origine au fichier audio. |
| `tags` |  | string | yes |  |  | Balises de style audio fournies sous forme de genres séparés par des virgules, avec `prompt` disponible comme méthode alternative pour les fournir. |
| `lyrics` |  | string | no | `` |  | Paroles chantées, avec les sections organisées à l'aide de contrôles tels que [verse], [chorus] et [bridge]. Pour un audio sans paroles chantées, omettez cette entrée ou fournissez uniquement [inst] ou [instrumental]. |
| `number_of_steps` |  | integer | no | `27` | 3 – 60 | Nombre d'étapes utilisées pendant la génération audio. |
| `seed` |  | integer \| null | no |  |  | Seed pour une génération reproductible, choisi aléatoirement sauf si vous fournissez une valeur. |
| `scheduler` |  | enum (string) | no | `euler` | `euler`, `heun` | Scheduler utilisé pendant la génération. |
| `guidance_type` |  | enum (string) | no | `apg` | `cfg`, `apg`, `cfg_star` | Type de CFG utilisé pendant la génération. |
| `granularity_scale` |  | integer | no | `10` | -100 – 100 | Échelle de granularité appliquée pendant la génération. L'augmenter peut réduire les artefacts. |
| `guidance_interval` |  | number | no | `0.5` | 0 – 1 | Portion du calendrier de génération qui reçoit des indications : la valeur 0.5 la limite aux étapes comprises entre 0.25 * infer_steps et 0.75 * infer_steps, laissant le début et la fin sans indications. |
| `guidance_interval_decay` |  | number | no | `0` | 0 – 1 | Décroissance des indications dans l'intervalle de génération : 0.0 désactive la décroissance ; sinon, l'échelle diminue sur cet intervalle, de guidance_scale à min_guidance_scale. |
| `guidance_scale` |  | number | no | `15` | 0 – 200 | Échelle des indications appliquées pendant la génération. |
| `minimum_guidance_scale` |  | number | no | `3` | 0 – 200 | Échelle minimale des indications atteinte après la décroissance pendant la génération. |
| `tag_guidance_scale` |  | number | no | `5` | 0 – 10 | Échelle des indications de balises appliquées pendant la génération. |
| `lyric_guidance_scale` |  | number | no | `1.5` | 0 – 10 | Échelle des indications de paroles appliquées pendant la génération. |
| `original_seed` |  | integer \| null | no |  |  | Seed associé à l'origine au fichier audio. |

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
{
  "tags": "lofi, hiphop, drum and bass, trap, chill",
  "audio": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
  "original_tags": "lofi, hiphop, drum and bass, trap, chill"
}
```

A fuller example:

```json
{
  "tags": "lofi, hiphop, drum and bass, trap, chill",
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
  "original_tags": "lofi, hiphop, drum and bass, trap, chill"
}
```

## 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/ace-step/audio-to-audio?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "original_tags": "lofi, hiphop, drum and bass, trap, chill"
  }'

# 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/ace-step/audio-to-audio?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "original_tags": "lofi, hiphop, drum and bass, trap, chill"
  }),
});
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 = {
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "original_tags": "lofi, hiphop, drum and bass, trap, chill",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ace-step/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": "ace-step/audio-to-audio",
      "input": {
        "tags": "lofi, hiphop, drum and bass, trap, chill",
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
        "original_tags": "lofi, hiphop, drum and bass, trap, chill"
      },
      "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": "ace-step/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": 2,
    "usd": "0.002",
    "charged": 2,
    "refunded": 0
  },
  "input": {
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
    "original_tags": "lofi, hiphop, drum and bass, trap, chill"
  },
  "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,
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "lyrics": "[inst]"
  },
  "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} | Fichier audio produit par la génération. |
| `seed` | integer | Seed aléatoire utilisé pendant la génération. |
| `tags` | string | Balises de genre appliquées pendant la génération. |
| `lyrics` | string | Paroles appliquées pendant la génération. |

## Related models

- [ACE Step](https://doitong.com/developers/models/ace-step.md) (`ace-step`): $0.0002 / second
- [ACE Step Audio Inpaint](https://doitong.com/developers/models/ace-step/audio-inpaint.md) (`ace-step/audio-inpaint`): $0.0002 / second of input audio
- [ACE Step Audio Outpaint](https://doitong.com/developers/models/ace-step/audio-outpaint.md) (`ace-step/audio-outpaint`): $0.0002 / second of output audio
- [ACE Step Prompt To Audio](https://doitong.com/developers/models/ace-step/prompt-to-audio.md) (`ace-step/prompt-to-audio`): $0.0002 / second
- [MiniMax Music 3](https://doitong.com/developers/models/minimax/music-3.md) (`minimax/music-3`): $0.002 / second
- [DiffRhythm: Lyrics to Song](https://doitong.com/developers/models/diffrhythm.md) (`diffrhythm`): $0.001 / second
- [Elevenlabs Music](https://doitong.com/developers/models/elevenlabs/music.md) (`elevenlabs/music`): $0.60 / minute of output audio
- [Elevenlabs Music v2](https://doitong.com/developers/models/elevenlabs/music/v2.md) (`elevenlabs/music/v2`): $0.60 / minute of output audio

## Links

- HTML page: https://doitong.com/developers/models/ace-step/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=ace-step/audio-to-audio
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ace-step/audio-to-audio