# ACE Step Audio Outpaint API

> מרחיב קטע שמע קיים לפני תחילתו או אחרי סופו באמצעות מוזיקה שהולחנה מחדש

ממשיך רצועה שסופקה דרך `audio_url`. `extend_before_duration` ו-`extend_after_duration` מוסיפים כל אחד עד 107 שניות בתחילת הרצועה או בסופה, וברירת המחדל היא 30 שניות אחרי הסוף. הסגנון נקבע לפי `tags`, עם `lyrics` אופציונליים לחלקים שנוספו. מספר הצעדים, המתזמן והגדרות ההנחיה תואמים למודלים האחרים של ACE Step.

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

## Pricing

Price: **$0.0002 / second of output audio**. Price per second of your output 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 $0.006 = 6 API credits (30 s output 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-outpaint` 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 |  |  | כתובת URL של קובץ האודיו להרחבה חיצונית. |
| `extend_before_duration` |  | number | no | `0` | 0 – 107 | אורך ההרחבה שלפני תחילת האודיו, בשניות. |
| `extend_after_duration` |  | number | no | `30` | 0 – 107 | אורך ההרחבה שאחרי סיום האודיו, בשניות. |
| `tags` |  | string | yes |  |  | תגיות סגנון אודיו שסופקו כז'אנרים מופרדים בפסיקים, כאשר `prompt` זמין כדרך חלופית לספק אותן. |
| `lyrics` |  | string | no | `` |  | מילים מושרות, כאשר חלקי השיר מאורגנים באמצעות פקדים כגון [verse], [chorus] ו-[bridge]. עבור אודיו ללא מילים מושרות, השמטו קלט זה או ספקו רק [inst] או [instrumental]. |
| `number_of_steps` |  | integer | no | `27` | 3 – 60 | מספר השלבים המשמש במהלך יצירת האודיו. |
| `seed` |  | integer \| null | no |  |  | Seed ליצירה חוזרת, שנבחר באקראי אלא אם תספקו ערך. |
| `scheduler` |  | enum (string) | no | `euler` | `euler`, `heun` | מתזמן המשמש במהלך היצירה. |
| `guidance_type` |  | enum (string) | no | `apg` | `cfg`, `apg`, `cfg_star` | סוג CFG המשמש במהלך היצירה. |
| `granularity_scale` |  | integer | no | `10` | -100 – 100 | סולם הגרעיניות המוחל במהלך היצירה. הגדלתו עשויה להפחית ארטיפקטים. |
| `guidance_interval` |  | number | no | `0.5` | 0 – 1 | חלק מלוח הזמנים של היצירה שמקבל הנחיה: בחירה ב-0.5 מגבילה אותה לשלבים מ-0.25 * infer_steps עד 0.75 * infer_steps, ומשאירה את ההתחלה והסוף ללא הנחיה. |
| `guidance_interval_decay` |  | number | no | `0` | 0 – 1 | דעיכת ההנחיה בתוך מרווח היצירה: 0.0 משאירה את הדעיכה מושבתת; אחרת, הסולם יורד לאורך המרווח מ-guidance_scale אל min_guidance_scale. |
| `guidance_scale` |  | number | no | `15` | 0 – 200 | סולם ההנחיה המוחל במהלך היצירה. |
| `minimum_guidance_scale` |  | number | no | `3` | 0 – 200 | סולם ההנחיה הנמוך ביותר שאליו מגיעים לאחר הדעיכה במהלך היצירה. |
| `tag_guidance_scale` |  | number | no | `5` | 0 – 10 | סולם הנחיית התגיות המוחל במהלך היצירה. |
| `lyric_guidance_scale` |  | number | no | `1.5` | 0 – 10 | סולם הנחיית המילים המוחל במהלך היצירה. |

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"
}
```

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"
}
```

## 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-outpaint?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"
  }'

# 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-outpaint?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"
  }),
});
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",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ace-step/audio-outpaint", 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-outpaint",
      "input": {
        "tags": "lofi, hiphop, drum and bass, trap, chill",
        "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": "ace-step/audio-outpaint",
  "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": 6,
    "usd": "0.006",
    "charged": 6,
    "refunded": 0
  },
  "input": {
    "tags": "lofi, hiphop, drum and bass, trap, chill",
    "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,
    "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} | קובץ האודיו שנוצר. |
| `seed` | integer | Seed אקראי המשמש במהלך היצירה. |
| `tags` | string | תגיות ז'אנר המוחלות במהלך היצירה. |
| `lyrics` | string | מילים המוחלות במהלך היצירה. |

## 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 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/audio-outpaint
- 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-outpaint
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ace-step/audio-outpaint