# ACE Step Audio Inpaint API

> Regeneréiert eng ausgewielte Zäitfënster vun enger bestoender Audiodatei mat neien Tags an Texter

Huelt eng `audio_url` a schreift nëmmen de Beräich tëscht `start_time` an `end_time` nei, allebéid a Sekonnen vun 0 bis 240 gemooss. All Zäit kann relativ zum Ufank oder Enn vum Clip gesat ginn. Nei `tags` an `lyrics` steieren den ersate Beräich, an `variance` kontrolléiert d'Variatioun vum Resultat. Déi üblech Guidance- a Schrëttastellunge si verfügbar.

- Model id: `ace-step/audio-inpaint`
- 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-inpaint`
- Quote: `POST https://api.doitong.com/v1/quote/ace-step/audio-inpaint`
- Docs page: https://doitong.com/lb/developers/models/ace-step/audio-inpaint

## 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-inpaint` 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 vun der Audio-Datei fir Inpainting. |
| `start_time_relative_to` |  | enum (string) | no | `start` | `start`, `end` | Referenzpunkt fir d'Ufankszäit: entweder den Ufank oder d'Enn vum Audio. |
| `start_time` |  | number | no | `0` | 0 – 240 | Ufankszäit vum Inpainting, gemooss a Sekonnen. |
| `end_time_relative_to` |  | enum (string) | no | `start` | `start`, `end` | Referenzpunkt fir d'Ennzäit: entweder den Ufank oder d'Enn vum Audio. |
| `end_time` |  | number | no | `30` | 0 – 240 | Ennzäit vum Inpainting, gemooss a Sekonnen. |
| `tags` |  | string | yes |  |  | Audio-Stil-Tags, déi als kommagetrennt Genres geliwwert ginn; alternativ kënnen se iwwer `prompt` uginn ginn. |
| `lyrics` |  | string | no | `` |  | Gesonge Liedtext, mat Song-Abschnitter, déi mat Steierungselementer wéi [verse], [chorus] an [bridge] organiséiert ginn. Fir Audio ouni gesonge Liedtext dës Input ewechloossen oder nëmmen [inst] oder [instrumental] uginn. |
| `variance` |  | number | no | `0.5` | 0 – 1 | D'Inpainting-Varianz bestëmmt, wéi divers d'Resultater kënne sinn; eng Erhéijung ka méi Variatioun aféieren. |
| `number_of_steps` |  | integer | no | `27` | 3 – 60 | Zuel vun de Schrëtt, déi bei der Audio-Generatioun benotzt ginn. |
| `seed` |  | integer \| null | no |  |  | Seed fir reproduzéierbar Generatioun; gëtt zoufälleg gewielt, ausser Dir gitt e Wäert un. |
| `scheduler` |  | enum (string) | no | `euler` | `euler`, `heun` | Scheduler, deen während der Generatioun benotzt gëtt. |
| `guidance_type` |  | enum (string) | no | `apg` | `cfg`, `apg`, `cfg_star` | CFG-Typ, deen während der Generatioun benotzt gëtt. |
| `granularity_scale` |  | integer | no | `10` | -100 – 100 | Granularitéits-Skala, déi während der Generatioun applizéiert gëtt. Eng Erhéijung kann Artefakter reduzéieren. |
| `guidance_interval` |  | number | no | `0.5` | 0 – 1 | Undeel vum Generatiouns-Zäitplang, op deen Guidance applizéiert gëtt: 0.5 beschränkt se op Schrëtt vun 0.25 * infer_steps bis 0.75 * infer_steps; den Ufank an d'Enn bleiwen ouni Guidance. |
| `guidance_interval_decay` |  | number | no | `0` | 0 – 1 | Ofbau vun der Guidance am Generatiounsintervall: 0.0 deaktivéiert den Ofbau; soss fält d'Skala iwwer dësen Intervall vu guidance_scale op min_guidance_scale. |
| `guidance_scale` |  | number | no | `15` | 0 – 200 | Skala vun der Guidance, déi während der Generatioun applizéiert gëtt. |
| `minimum_guidance_scale` |  | number | no | `3` | 0 – 200 | Niddregst Guidance-Skala, déi nom Ofbau während der Generatioun erreecht gëtt. |
| `tag_guidance_scale` |  | number | no | `5` | 0 – 10 | Skala vun der Tag-Guidance, déi während der Generatioun applizéiert gëtt. |
| `lyric_guidance_scale` |  | number | no | `1.5` | 0 – 10 | Skala vun der Liedtext-Guidance, déi während der Generatioun applizéiert gëtt. |

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-inpaint?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-inpaint?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-inpaint", 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-inpaint",
      "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-inpaint",
  "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"
  },
  "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} | Audio-Datei, déi duerch d'Generatioun erstallt gouf. |
| `seed` | integer | Zoufälleg Seed, deen während der Generatioun benotzt gouf. |
| `tags` | string | Genre-Tags, déi während der Generatioun applizéiert goufen. |
| `lyrics` | string | Liedtext, deen während der Generatioun applizéiert gouf. |

## Related models

- [ACE Step](https://doitong.com/developers/models/ace-step.md) (`ace-step`): $0.0002 / second
- [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/audio-inpaint
- 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-inpaint
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ace-step/audio-inpaint