# ACE Step Audio To Audio API

> Remixuje existující stopu nebo mění její text podle původních a nových tagů

Vychází z `audio_url` a jeho `original_tags` a pomocí nových `tags` mění styl. `edit_mode` je buď remix, který mění celkový zvuk, nebo lyrics, který upravuje pouze zpívaný obsah. Lze zadat `original_lyrics` a nové `lyrics` i `original_seed`, pokud je známý. Parametry kroků a guidance jsou stejné jako u ostatních modelů této řady.

- 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/cs/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 zvukového souboru pro outpainting. |
| `edit_mode` |  | enum (string) | no | `remix` | `lyrics`, `remix` | Režim úprav: změnit pouze text nebo remixovat zvuk. |
| `original_tags` |  | string | yes |  |  | Značky původně spojené se zvukovým souborem. |
| `original_lyrics` |  | string | no | `` |  | Text původně spojený se zvukovým souborem. |
| `tags` |  | string | yes |  |  | Značky stylu zvuku zadané jako žánry oddělené čárkami; alternativně je lze zadat pomocí `prompt`. |
| `lyrics` |  | string | no | `` |  | Zpívaný text s částmi skladby uspořádanými pomocí značek jako [verse], [chorus] a [bridge]. U zvuku bez zpívaného textu tento vstup vynechte nebo zadejte pouze [inst] či [instrumental]. |
| `number_of_steps` |  | integer | no | `27` | 3 – 60 | Počet kroků použitých při generování zvuku. |
| `seed` |  | integer \| null | no |  |  | Seed pro reprodukovatelné generování; pokud hodnotu nezadáte, vybere se náhodně. |
| `scheduler` |  | enum (string) | no | `euler` | `euler`, `heun` | Plánovač použitý při generování. |
| `guidance_type` |  | enum (string) | no | `apg` | `cfg`, `apg`, `cfg_star` | Typ CFG použitý při generování. |
| `granularity_scale` |  | integer | no | `10` | -100 – 100 | Měřítko granularitu použité při generování. Jeho zvýšení může omezit artefakty. |
| `guidance_interval` |  | number | no | `0.5` | 0 – 1 | Část plánu generování, na kterou se použije vedení: při volbě 0.5 je omezeno na kroky od 0.25 * infer_steps do 0.75 * infer_steps, takže začátek a konec zůstanou bez vedení. |
| `guidance_interval_decay` |  | number | no | `0` | 0 – 1 | Útlum vedení v intervalu generování: 0.0 ponechá útlum vypnutý; jinak se měřítko v tomto intervalu snižuje z guidance_scale na min_guidance_scale. |
| `guidance_scale` |  | number | no | `15` | 0 – 200 | Měřítko vedení použité při generování. |
| `minimum_guidance_scale` |  | number | no | `3` | 0 – 200 | Nejnižší měřítko vedení dosažené po útlumu během generování. |
| `tag_guidance_scale` |  | number | no | `5` | 0 – 10 | Měřítko vedení značek použité při generování. |
| `lyric_guidance_scale` |  | number | no | `1.5` | 0 – 10 | Měřítko vedení textu použité při generování. |
| `original_seed` |  | integer \| null | no |  |  | Seed původně spojený se zvukovým souborem. |

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} | Zvukový soubor vytvořený generováním. |
| `seed` | integer | Náhodný seed použitý při generování. |
| `tags` | string | Žánrové značky použité při generování. |
| `lyrics` | string | Text použitý při generování. |

## 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