---
title: "Seedance 2.5 UGC"
description: "Seedance 2.5 UGC makes an ad clip from a scene frame or from an ordered reference set. It holds the longest durations of every UGC lane and takes the widest reference budget."
url: https://docs.roasos.com/models/ugc/seedance-2.5
---

# Seedance 2.5 UGC

<Callout>
  Family 

  `ugc`

   · model 

  `seedance-2.5`

   · catalog 

  `model-catalog@2026-10-06.v5`

   · pricing 

  `customer-pricing@2026-11-05.v15`

  .
</Callout>

## Endpoint

```http
POST https://api.roasos.com/v1/ugc/seedance-2.5
```

Send your API key as a bearer token. The key needs the scope `api:write`. Every paid request also needs an `Idempotency-Key` header.

The envelope fields `quote_only`, `quote_id`, `webhook_url` and `wait_timeout_seconds` behave the same on each model endpoint. Refer to [Jobs](/concepts/jobs) and [Quotes and credits](/concepts/quotes-and-credits).

## Good at

A long clip (up to 30 seconds) and an ad that needs several product shots. Native audio. Reference mode takes a saved person, a saved product and your own style references together. Seedance accepts a face reference, a real photo or a saved avatar. If the provider refuses a face, the run fails with `provider_rejects_face_references` and roasOS refunds the reservation.

## Pricing

The unit is one **clip**. Pricing key: `seedance-2.5`.

| Request            | Credits |
| ------------------ | ------- |
| `4s_720p`          | 12      |
| `12s_720p`         | 36      |
| `30s_720p`         | 90      |
| `4s_720p_no_audio` | 12      |

The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with `quote_only: true` first.

## Modes

* `standard`
* `reference`

roasOS selects the mode from the media fields of your request. You do not send a mode.

Provider endpoints: `bytedance/seedance-2.5/image-to-video` · `bytedance/seedance-2.5/reference-to-video`.

## Request fields

| Field                  | Type         | Required | Default | Rule                                                   |
| ---------------------- | ------------ | -------- | ------- | ------------------------------------------------------ |
| `aspect_ratio`         | enum         | no       | `9:16`  | `auto`, `9:16`, `1:1`, `3:4`, `4:3`, `16:9`, `21:9`    |
| `avatar_id`            | string       | no       | —       | UUID; only in `reference`                              |
| `avatar_upload`        | string       | no       | —       | https URL; ≤ 4,096 characters; only in `reference`     |
| `duration_seconds`     | integer enum | no       | `5`     | `4`, `5`, `6`, `8`, `10`, `12`, `15`, `20`, `25`, `30` |
| `generate_audio`       | boolean      | no       | `true`  | —                                                      |
| `product_id`           | string       | no       | —       | UUID; only in `reference`                              |
| `prompt_mode`          | enum         | no       | —       | `wrapped`, `exact`                                     |
| `quote_id`             | string       | no       | —       | UUID                                                   |
| `quote_only`           | boolean      | no       | `false` | —                                                      |
| `references`           | string\[]    | no       | —       | ≤ 30 items; only in `reference`                        |
| `resolution`           | enum         | no       | `720p`  | `480p`, `720p`, `1080p`                                |
| `scene_id`             | string       | no       | —       | UUID; only in `standard`                               |
| `scene_image`          | string       | no       | —       | https URL; ≤ 4,096 characters; only in `standard`      |
| `script`               | string       | yes      | —       | ≥ 1 character; ≤ 10,000 characters                     |
| `video_urls`           | string\[]    | no       | —       | ≤ 3 items; only in `reference`                         |
| `wait_timeout_seconds` | integer      | no       | `0`     | 0–60                                                   |
| `webhook_url`          | string       | no       | —       | https URL; ≤ 4,096 characters                          |

The schema is strict. A field that is not in this table gets `400 unsupported_option`. The field names are the roasOS role names. One role has one name in every family.

## Media

This endpoint accepts these media roles:

* `avatar_id` — identity; the saved character reference sheet, with a derived portrait only where the model requires a single face or source frame
* `product_id` — product; resolves to the product image list
* `references` — style and appearance references
* `scene_id` — first frame — a scene this workspace owns
* `scene_image` — first frame — a CDN image
* `video_urls` — reference videos

| Role          | Items | Maximum size | Content types                           | Duration |
| ------------- | ----- | ------------ | --------------------------------------- | -------- |
| `references`  | ≤ 30  | 10 MB        | `image/jpeg`, `image/png`, `image/webp` | —        |
| `scene_image` | ≤ 1   | 10 MB        | `image/jpeg`, `image/png`, `image/webp` | —        |
| `video_urls`  | ≤ 3   | 100 MB       | `video/mp4`                             | 2–30 s   |

Every other role is refused: `elements`, `product_images`, `reference_images`, `image_url`, `end_image_url`, `video_url`, `audio_urls`, `audio_url`, `voice_id`. A refused role gets `400 unsupported_option`.

<Callout>
  Each media URL must be an immutable object on 

  `https://cdn.roasos.com`

   that your workspace owns. Any other URL gets 

  `400 reference_media_not_workspace_owned`

  . Refer to 

  [Reference media and uploads](/concepts/reference-media)

   to learn how to put a file there.
</Callout>

## Prompt

* Standard mode: the worker appends the UGC facts block ("Use the supplied first frame … The requested format is a UGC video ad; preserve the supplied script/action …") to the script.
* Reference mode: no facts block. Write no `@Image` tags yourself; the worker binds every reference.
* Write the words to be spoken in quotes: says exactly with warm energy: "…".
* Describe motion as physics: "Realistic hand movements, she lifts the jar to chest height."
* Anchor the hands to an object. A contact point holds hands and fabric better.
* Use a static camera for a talking head. Use one subject and one action for each clip.
* Do not write claims, camera moves or music that the product does not have.
* Seedance reads the ordered `@ImageN` tags. The worker writes them for you; do not write them yourself.

## Not exposed

These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.

* `duration_seconds` — these values are not available: `7`, `9`, `11`, `13`, `14`, `16`, `17`, `18`, `19`, `21`, `22`, `23`, `24`, `26`, `27`, `28`, `29`.
* `video_urls` — not accepted by this public endpoint.
* `audio_urls` — not accepted by this public endpoint.
* `seed` — not accepted by this public endpoint.
* `end_image_url` — not accepted by this public endpoint.
* `bitrate_mode` — pinned to `standard on every UGC request`.

## Result

The result kind is `ugc`. Always present: `url`.

```json
{
  "data": {
    "id": "gen_…",
    "kind": "ugc",
    "model": "seedance-2.5",
    "status": "completed",
    "result": {
      "url": "https://cdn.roasos.com/workspaces/ws_01/result"
    }
  }
}
```

The files are immutable objects on `https://cdn.roasos.com`. A result URL is a valid media input for your next request.

## Example

The three steps are always the same: quote, run, poll.

<CodeBlockTabs defaultValue="cURL">
  <CodeBlockTabsList>
    <CodeBlockTabsTrigger value="cURL">
      cURL
    </CodeBlockTabsTrigger>

    <CodeBlockTabsTrigger value="JavaScript">
      JavaScript
    </CodeBlockTabsTrigger>

    <CodeBlockTabsTrigger value="Python">
      Python
    </CodeBlockTabsTrigger>
  </CodeBlockTabsList>

  <CodeBlockTab value="cURL">
    ```bash
    # 1. Quote. Nothing is spent.
    curl -X POST https://api.roasos.com/v1/ugc/seedance-2.5 \
      -H "Authorization: Bearer roasos_sk_live_..." \
      -H "Idempotency-Key: 0f1c9e2a-seedance-2.5-0001" \
      -H "Content-Type: application/json" \
      -d '{"quote_only":true,"script":"Two drops, morning and night. That is the whole routine."}'
    # 200 { "data": { "kind": "quote", "quote_id": "q_7Hk...", "credits": 12, "expires_at": "...",
    #        "confirmation": { "model": "seedance-2.5", "example": "4s_720p" } } }

    # 2. Run. Same body, same Idempotency-Key, quote_id in place of quote_only.
    curl -X POST https://api.roasos.com/v1/ugc/seedance-2.5 \
      -H "Authorization: Bearer roasos_sk_live_..." \
      -H "Idempotency-Key: 0f1c9e2a-seedance-2.5-0001" \
      -H "Content-Type: application/json" \
      -d '{"quote_id":"q_7Hk...","script":"Two drops, morning and night. That is the whole routine."}'
    # 201 { "data": { "id": "gen_...", "status": "queued", "credits_reserved": 12 } }

    # 3. Poll, then read the result.
    curl https://api.roasos.com/v1/jobs/gen_.../status -H "Authorization: Bearer roasos_sk_live_..."
    curl https://api.roasos.com/v1/jobs/gen_.../result -H "Authorization: Bearer roasos_sk_live_..."
    ```
  </CodeBlockTab>

  <CodeBlockTab value="JavaScript">
    ```javascript
    const key = process.env.ROASOS_API_KEY;
    const url = "https://api.roasos.com/v1/ugc/seedance-2.5";
    const idempotencyKey = "0f1c9e2a-seedance-2.5-0001";
    const input = {
      "script": "Two drops, morning and night. That is the whole routine."
    };

    const post = (payload) =>
      fetch(url, {
        method: "POST",
        headers: {
          Authorization: `Bearer ${key}`,
          "Idempotency-Key": idempotencyKey,
          "Content-Type": "application/json",
        },
        body: JSON.stringify(payload),
      }).then((response) => response.json());

    // 1. Quote. Nothing is spent.
    const quote = await post({ quote_only: true, ...input });
    console.log(quote.data.credits);

    // 2. Run.
    const job = await post({ quote_id: quote.data.quote_id, ...input });

    // 3. Poll, then read the result.
    let status = "queued";
    while (status !== "completed" && status !== "failed" && status !== "canceled") {
      await new Promise((done) => setTimeout(done, 3000));
      const poll = await fetch(`${url.split("/v1")[0]}/v1/jobs/${job.data.id}/status`, {
        headers: { Authorization: `Bearer ${key}` },
      }).then((response) => response.json());
      status = poll.data.status;
    }

    const result = await fetch(`${url.split("/v1")[0]}/v1/jobs/${job.data.id}/result`, {
      headers: { Authorization: `Bearer ${key}` },
    }).then((response) => response.json());
    console.log(result.data.result);
    ```
  </CodeBlockTab>

  <CodeBlockTab value="Python">
    ```python
    import os, time, requests

    key = os.environ["ROASOS_API_KEY"]
    url = "https://api.roasos.com/v1/ugc/seedance-2.5"
    headers = {
        "Authorization": f"Bearer {key}",
        "Idempotency-Key": "0f1c9e2a-seedance-2.5-0001",
    }
    payload = {
        "script": "Two drops, morning and night. That is the whole routine."
    }

    # 1. Quote. Nothing is spent.
    quote = requests.post(url, headers=headers, json={"quote_only": True, **payload}).json()
    print(quote["data"]["credits"])

    # 2. Run.
    job = requests.post(url, headers=headers, json={"quote_id": quote["data"]["quote_id"], **payload}).json()
    job_id = job["data"]["id"]

    # 3. Poll, then read the result.
    jobs = "https://api.roasos.com/v1/jobs"
    status = "queued"
    while status not in ("completed", "failed", "canceled"):
        time.sleep(3)
        status = requests.get(f"{jobs}/{job_id}/status", headers=headers).json()["data"]["status"]

    result = requests.get(f"{jobs}/{job_id}/result", headers=headers).json()
    print(result["data"]["result"])
    ```
  </CodeBlockTab>
</CodeBlockTabs>

## Today

The app route `POST /api/generate/ugc-ads { sceneId | sceneImage, script, model: "seedance-2.5", async: true }` sends the same request. Use this endpoint instead: it is live.

## See also

* [`llms.txt` for this model](https://docs.roasos.com/models/ugc/seedance-2.5/llms.txt) — the same facts as one plain-text file for an agent.
* `GET https://api.roasos.com/v1/catalog/seedance-2.5` — the machine-readable form: enums, defaults, limits and prices. Refer to the [API reference](/api-reference/overview).
* [Jobs](/concepts/jobs) — how to poll a job and read its result.
* Provider endpoints: `bytedance/seedance-2.5/image-to-video` · `bytedance/seedance-2.5/reference-to-video`.