seedance-2.5 Video Generation

curl --request POST \
  --url https://api.apimart.ai/v1/videos/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30
  }'

import requests

url = "https://api.apimart.ai/v1/videos/generations"

payload = {
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30,
}

headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json",
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

const url = "https://api.apimart.ai/v1/videos/generations";

const payload = {
  model: "seedance-2.5",
  prompt: "A cinematic 30-second steampunk miniature landscape sequence",
  size: "16:9",
  resolution: "720p",
  duration: 30,
};

const headers = {
  Authorization: "Bearer <token>",
  "Content-Type": "application/json",
};

fetch(url, {
  method: "POST",
  headers: headers,
  body: JSON.stringify(payload),
})
  .then((response) => response.json())
  .then((data) => console.log(data))
  .catch((error) => console.error("Error:", error));

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
)

func main() {
    url := "https://api.apimart.ai/v1/videos/generations"

    payload := map[string]interface{}{
        "model":      "seedance-2.5",
        "prompt":     "A cinematic 30-second steampunk miniature landscape sequence",
        "size":       "16:9",
        "resolution": "720p",
        "duration":   30,
    }

    jsonData, _ := json.Marshal(payload)

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
    req.Header.Set("Authorization", "Bearer <token>")
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.URI;

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "https://api.apimart.ai/v1/videos/generations";

        String payload = """
        {
          "model": "seedance-2.5",
          "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
          "size": "16:9",
          "resolution": "720p",
          "duration": 30
        }
        """;

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Authorization", "Bearer <token>")
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(payload))
            .build();

        HttpResponse<String> response = client.send(request,
            HttpResponse.BodyHandlers.ofString());

        System.out.println(response.body());
    }
}

<?php

$url = "https://api.apimart.ai/v1/videos/generations";

$payload = [
    "model" => "seedance-2.5",
    "prompt" => "A cinematic 30-second steampunk miniature landscape sequence",
    "size" => "16:9",
    "resolution" => "720p",
    "duration" => 30
];

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
]);

$response = curl_exec($ch);
curl_close($ch);

echo $response;
?>

{
  "code": 200,
  "data": [
    {
      "status": "submitted",
      "task_id": "task_01KMCGF6BQGN3X28H3KSR50X5T"
    }
  ]
}

{
  "error": {
    "code": 400,
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": 401,
    "message": "Authentication failed. Please check your API key",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": 402,
    "message": "Insufficient balance. Please top up and try again",
    "type": "payment_required"
  }
}

{
  "error": {
    "code": 429,
    "message": "Too many requests. Please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": 500,
    "message": "Internal server error. Please try again later",
    "type": "server_error"
  }
}

POST

videos

generations

curl --request POST \
  --url https://api.apimart.ai/v1/videos/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30
  }'

import requests

url = "https://api.apimart.ai/v1/videos/generations"

payload = {
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30,
}

headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json",
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

const url = "https://api.apimart.ai/v1/videos/generations";

const payload = {
  model: "seedance-2.5",
  prompt: "A cinematic 30-second steampunk miniature landscape sequence",
  size: "16:9",
  resolution: "720p",
  duration: 30,
};

const headers = {
  Authorization: "Bearer <token>",
  "Content-Type": "application/json",
};

fetch(url, {
  method: "POST",
  headers: headers,
  body: JSON.stringify(payload),
})
  .then((response) => response.json())
  .then((data) => console.log(data))
  .catch((error) => console.error("Error:", error));

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
)

func main() {
    url := "https://api.apimart.ai/v1/videos/generations"

    payload := map[string]interface{}{
        "model":      "seedance-2.5",
        "prompt":     "A cinematic 30-second steampunk miniature landscape sequence",
        "size":       "16:9",
        "resolution": "720p",
        "duration":   30,
    }

    jsonData, _ := json.Marshal(payload)

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
    req.Header.Set("Authorization", "Bearer <token>")
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.URI;

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "https://api.apimart.ai/v1/videos/generations";

        String payload = """
        {
          "model": "seedance-2.5",
          "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
          "size": "16:9",
          "resolution": "720p",
          "duration": 30
        }
        """;

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Authorization", "Bearer <token>")
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(payload))
            .build();

        HttpResponse<String> response = client.send(request,
            HttpResponse.BodyHandlers.ofString());

        System.out.println(response.body());
    }
}

<?php

$url = "https://api.apimart.ai/v1/videos/generations";

$payload = [
    "model" => "seedance-2.5",
    "prompt" => "A cinematic 30-second steampunk miniature landscape sequence",
    "size" => "16:9",
    "resolution" => "720p",
    "duration" => 30
];

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
]);

$response = curl_exec($ch);
curl_close($ch);

echo $response;
?>

{
  "code": 200,
  "data": [
    {
      "status": "submitted",
      "task_id": "task_01KMCGF6BQGN3X28H3KSR50X5T"
    }
  ]
}

{
  "error": {
    "code": 400,
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": 401,
    "message": "Authentication failed. Please check your API key",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": 402,
    "message": "Insufficient balance. Please top up and try again",
    "type": "payment_required"
  }
}

{
  "error": {
    "code": 429,
    "message": "Too many requests. Please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": 500,
    "message": "Internal server error. Please try again later",
    "type": "server_error"
  }
}

Main changes vs 2.0: max duration 15s → 30s; references 9 images + 3 videos + 3 audios → 30 images + 10 videos + 10 audios; audio-only reference supported; mov output added.
Note: resolution supports 480p / 720p / 1080p (2.0’s 4k is not available on 2.5).

curl --request POST \
  --url https://api.apimart.ai/v1/videos/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30
  }'

import requests

url = "https://api.apimart.ai/v1/videos/generations"

payload = {
    "model": "seedance-2.5",
    "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
    "size": "16:9",
    "resolution": "720p",
    "duration": 30,
}

headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json",
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

const url = "https://api.apimart.ai/v1/videos/generations";

const payload = {
  model: "seedance-2.5",
  prompt: "A cinematic 30-second steampunk miniature landscape sequence",
  size: "16:9",
  resolution: "720p",
  duration: 30,
};

const headers = {
  Authorization: "Bearer <token>",
  "Content-Type": "application/json",
};

fetch(url, {
  method: "POST",
  headers: headers,
  body: JSON.stringify(payload),
})
  .then((response) => response.json())
  .then((data) => console.log(data))
  .catch((error) => console.error("Error:", error));

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "net/http"
)

func main() {
    url := "https://api.apimart.ai/v1/videos/generations"

    payload := map[string]interface{}{
        "model":      "seedance-2.5",
        "prompt":     "A cinematic 30-second steampunk miniature landscape sequence",
        "size":       "16:9",
        "resolution": "720p",
        "duration":   30,
    }

    jsonData, _ := json.Marshal(payload)

    req, _ := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
    req.Header.Set("Authorization", "Bearer <token>")
    req.Header.Set("Content-Type", "application/json")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, _ := ioutil.ReadAll(resp.Body)
    fmt.Println(string(body))
}

import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.URI;

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "https://api.apimart.ai/v1/videos/generations";

        String payload = """
        {
          "model": "seedance-2.5",
          "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
          "size": "16:9",
          "resolution": "720p",
          "duration": 30
        }
        """;

        HttpClient client = HttpClient.newHttpClient();
        HttpRequest request = HttpRequest.newBuilder()
            .uri(URI.create(url))
            .header("Authorization", "Bearer <token>")
            .header("Content-Type", "application/json")
            .POST(HttpRequest.BodyPublishers.ofString(payload))
            .build();

        HttpResponse<String> response = client.send(request,
            HttpResponse.BodyHandlers.ofString());

        System.out.println(response.body());
    }
}

<?php

$url = "https://api.apimart.ai/v1/videos/generations";

$payload = [
    "model" => "seedance-2.5",
    "prompt" => "A cinematic 30-second steampunk miniature landscape sequence",
    "size" => "16:9",
    "resolution" => "720p",
    "duration" => 30
];

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
]);

$response = curl_exec($ch);
curl_close($ch);

echo $response;
?>

{
  "code": 200,
  "data": [
    {
      "status": "submitted",
      "task_id": "task_01KMCGF6BQGN3X28H3KSR50X5T"
    }
  ]
}

{
  "error": {
    "code": 400,
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": 401,
    "message": "Authentication failed. Please check your API key",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": 402,
    "message": "Insufficient balance. Please top up and try again",
    "type": "payment_required"
  }
}

{
  "error": {
    "code": 429,
    "message": "Too many requests. Please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": 500,
    "message": "Internal server error. Please try again later",
    "type": "server_error"
  }
}

Authentication

string

required

Bearer token auth. Get a key from the API Key page.

Authorization: Bearer YOUR_API_KEY

Request parameters

string

required

Fixed value: seedance-2.5

boolean

default:"false"

Whether to run content moderation before submitting the video task.

true: use omni-moderation-latest to review prompts and input images
false or omitted: do not send a moderation request, adding no moderation cost or latency (default)

Content reviewed:

Text: prompt, negative_prompt
Images: image_urls, image_with_roles[].url, first_frame_image, last_frame_image
Image-type private asset:// assets: resolve and review their original public URL
Base64 images: review them after conversion to a public URL

video_urls, audio_urls, and video/audio private assets are not reviewed, because the moderation model does not support video or audio.Supported model IDs: seedance-2.0, seedance-2.0-fast, seedance-2.0-mini, seedance-2.0-face, seedance-2.0-fast-face, seedance-2-0 (legacy), and seedance-2.5.The moderation call itself is not billed to the user submitting the video request.

Flagged content returns a synchronous HTTP 400 (nsfw_content_detected). No task or task_id is created, and no video-generation quota is charged
If moderation is unavailable, times out, or returns an invalid response, the request fails open and generation continues. Do not treat this option as an absolute content-safety guarantee
Inputs that cannot be resolved to a public image URL are skipped; unsupported models silently ignore nsfw_check: true

Example:

{
  "model": "seedance-2.5",
  "prompt": "a cat walking on the beach",
  "image_urls": ["https://cdn.example.com/ref.png"],
  "nsfw_check": true
}

Response when flagged:

{
  "error": {
    "message": "Your request was rejected by content moderation (`nsfw_check` is enabled). Flagged categories: sexual, violence/graphic.",
    "type": "nsfw_content_detected",
    "param": "",
    "code": "nsfw_content_detected"
  }
}

string

required

Prompt. Reference media with @图片1 / @视频1 / @音频1 (1-based index matching array order). English aliases in prompts may also be used depending on model behavior; keep indices aligned with arrays.Example: "Use @视频1 for first-person framing throughout, @音频1 as BGM, first frame is @图片1"

string

default:"720p"

Resolution — only:

480p
720p (default)
1080p

Unsupported values like 2k / 4k return a sync 400.

string

default:"adaptive"

Aspect ratio (field name aspect_ratio is also accepted).Values: 16:9, 4:3, 1:1, 3:4, 9:16, 21:9, adaptive (default)

Edit, extend, and first/last-frame jobs have hard size constraints — see Task types and constraints.

integer

default:"5"

Duration in seconds:

4 ~ 30
-1: model picks duration (pre-charge at the 30s cap; settle to actual length after completion)

If omitted: generate and bill 5 seconds.

boolean

default:"true"

Whether to generate audio (alias field name: audio).

true: with audio (default)
false: silent video

boolean

default:"false"

Add an “AI generated” watermark. Default false.

integer

Random seed. Different seeds usually yield different results for the same request; the same seed is similar but not guaranteed identical.

string

default:"mp4"

Output container:

mp4 (default)
mov: higher color precision — recommended for edit / extend workflows

string

default:"auto"

Sub-task type hint: auto / reference / edit / extend.Passing reference / edit / extend validates that type’s constraints at submit time. Invalid requests return 400, create no task, and charge nothing. See Task types and constraints.

array<string>

Reference image URLs, all treated as reference_image.Supports:

Public URL: https://example.com/pic.jpg
Private asset: asset://cm9xxxxxxxx

For first/last frames use image_with_roles.

Max 30 images
Prefer image_with_roles for first/last-frame roles

array<object>

Images with explicit roles.

Show Fields

string

required

Image URL or asset://...

string

required

first_frame: first frame (1 image)
last_frame: last frame (1 image, usually with first frame)
reference_image: reference image (up to 30 total)

Example:

[
  {"url": "https://example.com/first.jpg", "role": "first_frame"},
  {"url": "https://example.com/last.jpg", "role": "last_frame"}
]

If video_urls / audio_urls are present, first_frame / last_frame are auto-converted to reference_image (multimodal reference job).

array<string>

Reference videos (reference_video).Input: video URL or asset ID (asset://...).See Reference video specs.

array<string>

Reference audio URLs (reference_audio). Public URLs or asset://....Max 10; total duration ≤ 30s (each clip 2~30s).

2.5 supports audio-only reference (no image/video required).

boolean

default:"false"

When true, the successful result also includes the last-frame image for chaining.

array<object>

Tool list for enhancements such as web search.Example:

"tools": [{"type": "web_search"}]

Show Fields

string

required

Tool typeValues:

web_search — web search; generation can ground on online information

Media limits

Media	Limits
Images	≤30; jpeg / png / webp / bmp / tiff / gif / heic / heif; aspect ratio [0.4, 2.5]; side length [300, 6000]px; each <30MB
Videos	See Reference video specs
Audio	≤10; wav / mp3; each [2, 30]s and total ≤30s; each ≤15MB

Reference video specs

Input: video URL or asset ID (asset://...)
Container: mp4, mov — codecs in the table below
Resolution: 480p, 720p, 1080p
Duration: each clip [2, 30] s; up to 10 reference videos; total duration of all videos ≤ 30s
Per-video dimensions:
- Aspect ratio (width/height): [0.4, 2.5]
- Side length (px): [300, 6000]
- Total pixels: [640×640=409600, 3326×2494=8295044], i.e. width × height must fall in [409600, 8295044]
Size: each video ≤ 200 MB
Frame rate (FPS): [24, 60]

Supported codecs

Container	Video codec	Audio codec
`mp4`	H.264 / H.265	AAC / MP3
`mov`	H.264 / H.265	AAC / MP3

Task types and constraints

The service infers task type from references and prompt intent. The last three types hard-constrain size / duration; violations fail asynchronously after the job starts (e.g. InvalidParameter.TaskTypeConstraint):

Task type	Trigger	Constraints
Text-to-video	Text only	None
Reference-to-video	References + normal descriptive prompt	None. Avoid words like “edit / extend / continue / delete / replace” in the prompt to prevent misclassification
Video edit	References + prompt with “edit video / add / delete / modify / replace”, etc.	`size` must be `adaptive`, `duration` must be `-1`; source video 4~30s
Video extend	References + prompt with “extend forward/backward / continue / sequel”	`size` must be `adaptive`
First / first–last frame	`image_with_roles` uses `first_frame` / `last_frame`	`size` must be `adaptive` (also checked at submit time)

Turn async errors into sync errors with `omni_reference_task_type`

Passing reference / edit / extend declares the sub-task type so its constraints are validated at submit time. Invalid requests return 400 immediately: no task is created and nothing is charged — you do not have to poll until failed.

Value	Meaning	Constraints checked at submit
`auto` (default)	Model infers the type	None (violations fail asynchronously)
`reference`	Reference-to-video	None (`size` / `duration` unrestricted)
`edit`	Video edit	At least one item in `video_urls`; `size` must be `adaptive` (or omitted); `duration` must be `-1` (or omitted, see below); source video 4~30s
`extend`	Video extend	At least one item in `video_urls`; `size` must be `adaptive` (or omitted)

Notes:

If edit omits duration, the platform sets it to -1. Omitting duration otherwise defaults to 5 seconds, which conflicts with the upstream edit requirement of -1. The trade-off is a 30-second prepaid hold (same as duration: -1); unused amount is refunded after completion. For a smaller hold, skip edit and use default auto.
If edit sends duration explicitly, it must be -1. Any other value returns 400 (output length follows the source video).
⚠️ You can still fail asynchronously with InvalidParameter.TaskTypeMismatch. Upstream re-classifies the job from the prompt; a mismatch with your declared type is rejected. Keep prompt wording aligned (edit: “edit / delete / replace…”; extend: “extend forward/backward / continue…”).
All Seedance 2.5 channels share the same validation and upstream payload; switching channels does not change this behavior.

Asset library

You can pass public URLs as references, or upload into the library first and use asset://. Prefer the library when:

Real human faces must use the library — raw URLs are blocked by content moderation; only approved library assets can be used
Assets are reused often — upload once, skip repeated moderation on later jobs, faster submits
URLs are signed temporary links — the platform stores a durable copy on ingest so later use does not depend on the original URL staying alive
Library assets are synced to all available channels so multi-channel routing can use them wherever the job lands

The library is shared with the 2.0 family; approved asset:// IDs work in both 2.0 and 2.5 generation requests. Full submit fields: also see Private avatar assets.

Upload assets

POST /v1/seedance2/private-avatar/assets
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

curl --request POST \
  --url https://api.apimart.ai/v1/seedance2/private-avatar/assets \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "seedance-2.5",
    "group": { "name": "my-assets" },
    "asset_type": "Image",
    "assets": [
      { "url": "https://example.com/a.png", "name": "a" },
      { "url": "https://example.com/b.png", "name": "b" }
    ]
  }'

Field	Required	Description
`model`	No	Model the assets will be used with (defaults to 2.0). Sets the duration tier; for 2.5 pass `seedance-2.5`
`group`	No	Asset group; created automatically if omitted
`asset_type`	Yes	`Image` / `Video` / `Audio`
`assets[].url`	Yes	Public media URL
`assets[].name`	No	Asset name

The response includes a local task id. Poll with Get task status (GET /v1/tasks/{id}). After approval, list assets to obtain the asset:// ID.

Media limits (validated at submit)

Violations return 400 immediately (which asset index and which rule), without starting moderation or consuming moderation quota:

Media	Limits
Image	jpeg / png / webp / bmp / tiff / gif / heic / heif; side length [300, 6000]px; aspect ratio [0.4, 2.5]; each <30MB
Video	mp4 / mov; each ≤200MB; duration by model: 2.0 family [2, 15]s, 2.5 [2, 30]s
Audio	wav / mp3; each ≤15MB; duration tiers same as video

Error example:

{
  "error": {
    "code": "invalid_asset_material",
    "message": "video #1: duration must be between 2s and 15s for seedance-2.0 (got 30s)"
  }
}

For 30s video assets, submit with "model": "seedance-2.5" (2.0 cannot use assets longer than 15s).
If the platform cannot probe the media (e.g. network blip), it may pass through and leave the decision to moderation.

Use in generation requests

Reference approved assets with asset:// in image_urls / image_with_roles / video_urls / audio_urls:

{
  "model": "seedance-2.5",
  "prompt": "The person in @图片1 walks along the beach",
  "image_urls": ["asset://cm9xxxxxxxx"],
  "duration": 8
}

Multi-channel: after ingest, assets sync to all available channels so any routed channel can use them. If a channel’s copy is missing, the platform may re-upload from the original URL as a fallback (if that URL is already expired, that channel is skipped and another takes over).

Management APIs (quick reference)

Method	Path	Purpose
`GET`	`/v1/seedance2/private-avatar/assets`	List assets
`GET`	`/v1/seedance2/private-avatar/assets/{asset_id}`	Asset detail (incl. moderation status)
`PATCH`	`/v1/seedance2/private-avatar/assets/{asset_id}`	Update asset metadata
`DELETE`	`/v1/seedance2/private-avatar/assets/{asset_id}`	Delete asset
`POST` / `GET` / `PATCH` / `DELETE`	`/v1/seedance2/private-avatar/groups[/{id}]`	Asset group management

Asset APIs are free of charge (auth + rate limits only); they do not create billing records.

FAQ

Q: How long does moderation take?
Images usually seconds; video and real-person assets may take minutes. Poll the task id until a terminal status. Q: Moderation failed with no clear reason?
Some failures omit a detailed reason (often a transient fetch failure). The platform already retries once; if it still fails, change the URL (ensure it is publicly downloadable) and resubmit. Q: Same asset for both 2.0 and 2.5 — upload twice?
No. Upload once; asset:// works for both generations. Cross-channel / cross-model sync is handled by the platform. Q: Can I pass a real-person face as a raw URL?
Real-person assets must go through the library first.

Billing

Billed by seconds × resolution tier.
With reference video input: billable seconds = total input video duration (≤30s) + output duration, at the input-reference rate tier.
duration = -1 (auto): pre-charge at the 30s cap; settle to actual output after completion.
Omit duration: generate and bill 5 seconds.
Failed jobs or content moderation blocks: full refund (charge only on successful output).

Request examples

Text-to-video (30s)

{
  "model": "seedance-2.5",
  "prompt": "A cinematic 30-second steampunk miniature landscape sequence",
  "size": "16:9",
  "resolution": "720p",
  "duration": 30
}

Multimodal reference (image + video + audio)

{
  "model": "seedance-2.5",
  "prompt": "Use @视频1 for first-person framing, @音频1 as BGM, first frame is @图片1",
  "image_urls": [
    "https://example.com/pic1.jpg",
    "https://example.com/pic2.jpg"
  ],
  "video_urls": ["https://example.com/ref.mp4"],
  "audio_urls": ["https://example.com/bgm.mp3"],
  "size": "16:9",
  "duration": 11
}

Video edit

{
  "model": "seedance-2.5",
  "prompt": "Edit the video: remove all passers-by in @视频1, keep only the main character",
  "video_urls": ["https://example.com/input.mp4"],
  "size": "adaptive",
  "duration": -1,
  "output_format": "mov"
}

First–last frame

{
  "model": "seedance-2.5",
  "prompt": "The girl in the image says \"cheese\" to the camera, 360-degree orbit shot",
  "image_with_roles": [
    {"url": "https://example.com/first.jpg", "role": "first_frame"},
    {"url": "https://example.com/last.jpg", "role": "last_frame"}
  ],
  "size": "adaptive",
  "duration": 5
}

Private asset

{
  "model": "seedance-2.5",
  "prompt": "A person walking naturally on a city street in sunlight",
  "image_urls": ["asset://cm9xxxxxxxx"],
  "duration": 5,
  "resolution": "720p"
}

Web search

{
  "model": "seedance-2.5",
  "prompt": "Generate a short tech-news video intro based on the latest information",
  "size": "16:9",
  "resolution": "720p",
  "duration": 8,
  "tools": [{"type": "web_search"}]
}

Common errors

Symptom	Cause
400 unsupported `resolution`	Passed unsupported values such as `2k` / `4k`
400 `This model only supports duration 4-30 seconds, or -1`	`duration` out of range
400 `first_frame/last_frame tasks only support ratio=adaptive`	First/last-frame job with a fixed aspect ratio
Async failure (edit / extend style message)	Prompt classified as edit/extend but `size` / `duration` violate that type’s rules
Async failure `SensitiveContentDetected`	Media or output failed moderation

Response (submit)

integer

Status code; 200 on success

array

Submit response with status / task_id

Show Array item

string

Initially submitted

string

Task ID for status polling

Completed task (`GET /v1/tasks/{task_id}`)

After submit, poll with Get task status. When status is completed, the payload looks like this.

Completed response example

{
  "code": 200,
  "data": {
    "id": "task_01KZEWTMH6TG3Z1X2QRP2B9ZG9",
    "status": "completed",
    "progress": 100,
    "created": 1786132648,
    "completed": 1786132748,
    "actual_time": 100,
    "estimated_time": 300,
    "cost": 0.3104,
    "credits_cost": 3.104,
    "usage": {
      "completion_tokens": 38800
    },
    "result": {
      "videos": [
        {
          "url": [
            "https://cdn.example.com/video/…-video_task_01KZEWTMH6TG3Z1X2QRP2B9ZG9.mp4"
          ],
          "expires_at": 1786219148
        }
      ]
    }
  }
}

Completed fields

Field	Type	Description
`data.id`	string	Task ID
`data.status`	string	Always `completed` when done
`data.progress`	int	Always `100` when done
`data.created` / `data.completed`	int	Submit / finish time (Unix seconds)
`data.actual_time`	int	Elapsed seconds = completed − created
`data.estimated_time`	int	Platform ETA in seconds (reference only)
`data.cost`	float	Actual charge in USD for this job (includes discounts; matches billing logs)
`data.credits_cost`	float	Credits charged = `cost × 10`
`data.usage.completion_tokens`	int	Tokens consumed. Settlement: `cost = completion_tokens ÷ 10⁶ × token unit price × discount`
`data.result.videos[].url`	string[]	Video URL(s). This is an array — use `url[0]`. Values are long-lived platform CDN URLs after re-hosting
`data.result.videos[].expires_at`	int	Expiry timestamp (kept for compatibility; re-hosted URLs are long-lived)
`data.result.videos[].last_frame_url`	string	Last-frame image (only if submit used `return_last_frame=true`)

Notes

Failed tasks (status=failed): cost is always 0 (pre-charge fully refunded); reason in data.error.message
usage may be missing for a few seconds after completion (settlement lag); query again shortly

Differences from 2.0

Feature	2.0	2.5
Model	`seedance-2.0`, etc.	`seedance-2.5`
Duration	~4–15s	4–30s, or `-1` auto
Resolution	480p / 720p / 1080p / 4k	480p / 720p / 1080p
Reference images	≤9	≤30
Reference videos	≤3, total ~<15s	≤10, total ≤30s
Reference audio	≤3, total ≤15s	≤10, total ≤30s; audio-only OK
Output format	Mainly mp4	mp4 / mov
Watermark	—	`watermark`
Private `asset://`	Supported	Shared with the same private APIs

Overview

Models

Text Series

Image Series

Video Series

Audio Series

Moderation Series

Upload Management

Task Management

Account Management

seedance-2.5 Video Generation

Authentication

Request parameters

Media limits

Reference video specs

Supported codecs

Task types and constraints

Turn async errors into sync errors with `omni_reference_task_type`

Asset library

Upload assets

Media limits (validated at submit)

Use in generation requests

Management APIs (quick reference)

FAQ

Billing

Request examples

Text-to-video (30s)

Multimodal reference (image + video + audio)

Video edit

First–last frame

Private asset

Web search

Common errors

Response (submit)

Completed task (`GET /v1/tasks/{task_id}`)

Completed response example

Completed fields

Notes

Differences from 2.0

​Authentication

​Request parameters

​Media limits

​Reference video specs

​Supported codecs

​Task types and constraints

​Turn async errors into sync errors with omni_reference_task_type

​Asset library

​Upload assets

​Media limits (validated at submit)

​Use in generation requests

​Management APIs (quick reference)

​FAQ

​Billing

​Request examples

​Text-to-video (30s)

​Multimodal reference (image + video + audio)

​Video edit

​First–last frame

​Private asset

​Web search

​Common errors

​Response (submit)

​Completed task (GET /v1/tasks/{task_id})

​Completed response example

​Completed fields

​Notes

​Differences from 2.0

Authentication

Request parameters

Media limits

Reference video specs

Supported codecs

Task types and constraints

Turn async errors into sync errors with `omni_reference_task_type`

Asset library

Upload assets

Media limits (validated at submit)

Use in generation requests

Management APIs (quick reference)

FAQ

Billing

Request examples

Text-to-video (30s)

Multimodal reference (image + video + audio)

Video edit

First–last frame

Private asset

Web search

Common errors

Response (submit)

Completed task (`GET /v1/tasks/{task_id}`)

Completed response example

Completed fields

Notes

Differences from 2.0