# ACE Step API

> 장르 태그와 선택적 가사로 5~240초 길이의 음악을 작곡합니다

쉼표로 구분된 스타일 `tags`와 선택적 `lyrics`로 음악 트랙을 생성합니다. [verse] 및 [chorus]와 같은 섹션 마커로 곡 구조를 정하고, [inst]를 사용하면 연주곡이 생성됩니다. `duration`은 5~240초입니다. 샘플링 제어에는 `scheduler`(euler 또는 heun), `guidance_type`, 3~60 범위의 `number_of_steps`가 포함됩니다.

- Model id: `ace-step`
- Made by: ACE Studio
- Category: Text to Music
- Output: audio
- Price: $0.0002 / second (60 s ≈ $0.012) (cheapest run $0.012 (12 API credits))
- Run: `POST https://api.doitong.com/v1/run/ace-step`
- Quote: `POST https://api.doitong.com/v1/quote/ace-step`
- Docs page: https://doitong.com/ko/developers/models/ace-step

## Pricing

Price: **$0.0002 / second (60 s ≈ $0.012)**. Billed per second of output (`duration`, default 240).

The full example input below costs $0.012 = 12 API credits (60 s × 0.2 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/ace-step` 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

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `tags` |  | string | yes |  |  | 쉼표로 구분된 장르의 오디오 스타일 태그입니다. 태그를 제공하는 다른 방법으로 `prompt`를 사용할 수 있습니다. |
| `lyrics` |  | string | no | `` |  | [verse], [chorus], [bridge] 같은 컨트롤로 곡의 구간을 구성한 가사입니다. 가사가 없는 오디오는 이 입력을 생략하거나 [inst] 또는 [instrumental]만 제공하세요. |
| `duration` |  | number | no | `60` | 5 – 240 | 생성되는 오디오의 길이(초)입니다. |
| `number_of_steps` |  | integer | no | `27` | 3 – 60 | 오디오 생성에 사용되는 단계 수입니다. |
| `seed` |  | integer \| null | no |  |  | 재현 가능한 생성을 위한 시드입니다. 값을 제공하지 않으면 무작위로 선택됩니다. |
| `scheduler` |  | enum (string) | no | `euler` | `euler`, `heun` | 생성 중 사용할 스케줄러입니다. |
| `guidance_type` |  | enum (string) | no | `apg` | `cfg`, `apg`, `cfg_star` | 생성 중 사용할 CFG 유형입니다. |
| `granularity_scale` |  | integer | no | `10` | -100 – 100 | 생성 중 적용되는 세부 수준입니다. 높이면 아티팩트가 줄어들 수 있습니다. |
| `guidance_interval` |  | number | no | `0.5` | 0 – 1 | 가이드가 적용되는 생성 스케줄의 구간입니다. 0.5를 선택하면 0.25 * infer_steps부터 0.75 * infer_steps까지의 단계로 제한되며, 시작과 끝에는 가이드가 적용되지 않습니다. |
| `guidance_interval_decay` |  | number | no | `0` | 0 – 1 | 생성 구간 내 가이드 감쇠입니다. 0.0은 감쇠를 비활성화하고, 그 외의 값은 해당 구간에서 guidance_scale을 min_guidance_scale까지 감소시킵니다. |
| `guidance_scale` |  | number | no | `15` | 0 – 200 | 생성 중 적용되는 가이드 강도입니다. |
| `minimum_guidance_scale` |  | number | no | `3` | 0 – 200 | 생성 중 감쇠 후 도달하는 최저 가이드 강도입니다. |
| `tag_guidance_scale` |  | number | no | `5` | 0 – 10 | 생성 중 적용되는 태그 가이드 강도입니다. |
| `lyric_guidance_scale` |  | number | no | `1.5` | 0 – 10 | 생성 중 적용되는 가사 가이드 강도입니다. |

## Example input

Required parameters only:

```json
{
  "tags": "lofi, hiphop, drum and bass, trap, chill"
}
```

A fuller example:

```json
{
  "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?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "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?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "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",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ace-step", 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",
      "input": {
        "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",
  "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": 12,
    "usd": "0.012",
    "charged": 12,
    "refunded": 0
  },
  "input": {
    "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} | 생성으로 만들어진 오디오 파일입니다. |
| `seed` | integer | 생성에 사용된 무작위 시드입니다. |
| `tags` | string | 생성 중 적용된 장르 태그입니다. |
| `lyrics` | string | 생성 중 적용된 가사입니다. |

## Related models

- [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 Audio To Audio](https://doitong.com/developers/models/ace-step/audio-to-audio.md) (`ace-step/audio-to-audio`): $0.0002 / second of input 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
- 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
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ace-step