Seedance 2.5 API

Overview

Seedance 2.5 is a ByteDance video generation model for prompt-only video, first-and-last-frame animation, and multimodal reference workflows. Use this page when you need up to 30-second video generation with optional image, video, or audio references.

Capability	Value
Model ID	`seedance-2-5`
Modes	`text-to-video`, `first_and_last_frames`, `omni_reference`
Prompt	Required non-empty string; no API-side maximum length
Resolutions	`480p`, `720p`
Durations	Any integer from `4` through `30` seconds, or `-1` for dynamic duration
Aspect ratios	`auto`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`
Reference images	1-2 URLs for `first_and_last_frames`; 1-30 URLs for `omni_reference`
Reference video/audio	1-10 URLs each for `omni_reference`; each file 2-30 seconds, total max 30 seconds per media type
Output	Video URL array in `resultJson.resultUrls`

Prompts that describe video-editing actions may be treated as video editing by the generation system. This includes phrases such as edit video, add, add to, delete, remove, modify, replace, change to, and Chinese phrases such as 编辑视频, 增加, 加上, 删除, 去掉, 修改, 替换, or 改成. For these prompts, set duration to -1 and aspect_ratio to auto.

Endpoint and authentication

Base URL:

https://api.apixo.ai/api/v1

Method	Endpoint	Purpose
`POST`	`/generateTask/seedance-2-5`	Submit a generation task
`GET`	`/statusTask/seedance-2-5?taskId={taskId}`	Poll task status and retrieve results

All requests require your APIXO API key:

Authorization: Bearer YOUR_API_KEY

Submit requests also require:

Content-Type: application/json

Copy-paste async quickstart

This minimal request submits a text-to-video task and returns a taskId.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/seedance-2-5" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "async",
    "input": {
      "mode": "text-to-video",
      "prompt": "a cinematic night city drone shot with dramatic lighting",
      "resolution": "720p",
      "duration": 8,
      "aspect_ratio": "16:9",
      "sound": true
    }
  }'

Successful response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678"
  }
}

Save the taskId; you need it to poll for the final result.

Poll for result

curl -X GET "https://api.apixo.ai/api/v1/statusTask/seedance-2-5?taskId=task_12345678" \
  -H "Authorization: Bearer YOUR_API_KEY"

Processing response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "processing",
    "createTime": 1767965610929
  }
}

Success response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "success",
    "resultJson": "{\"resultUrls\":[\"https://file.apixo.ai/video.mp4\"]}",
    "createTime": 1767965610929,
    "completeTime": 1767965890929,
    "costTime": 280000
  }
}

Failed response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "GenerationError",
    "failMsg": "Generation failed",
    "createTime": 1767965610929,
    "completeTime": 1767965620132
  }
}

Parse resultJson after state becomes success:

const payload = JSON.parse(data.resultJson);
const videoUrls = payload.resultUrls;

Request body

Text-to-video

{
  "request_type": "async",
  "input": {
    "mode": "text-to-video",
    "prompt": "a slow tracking shot through a foggy pine forest at dawn",
    "resolution": "720p",
    "duration": 10,
    "aspect_ratio": "16:9",
    "sound": true
  }
}

Dynamic duration

Use duration=-1 when you want the generation system to decide the final output length.

{
  "request_type": "async",
  "input": {
    "mode": "text-to-video",
    "prompt": "a continuous cooking tutorial scene with natural camera transitions",
    "resolution": "720p",
    "duration": -1,
    "aspect_ratio": "auto",
    "sound": true
  }
}

First-and-last-frames

{
  "request_type": "async",
  "input": {
    "mode": "first_and_last_frames",
    "prompt": "turn the still frames into a smooth cinematic camera move",
    "image_urls": [
      "https://example.com/frame-start.png",
      "https://example.com/frame-end.png"
    ],
    "resolution": "720p",
    "duration": 5,
    "aspect_ratio": "auto",
    "sound": true
  }
}

Omni-reference

{
  "request_type": "async",
  "input": {
    "mode": "omni_reference",
    "prompt": "create a stylish product ad using the visual references and voice rhythm",
    "image_urls": [
      "https://example.com/product-shot.png"
    ],
    "video_urls": [
      "https://example.com/ref-motion.mp4"
    ],
    "audio_urls": [
      "https://example.com/ref-audio.mp3"
    ],
    "resolution": "480p",
    "duration": 6,
    "aspect_ratio": "auto",
    "sound": true,
    "output_format": "mp4",
    "watermark": false
  }
}

Parameters

string

default:"async"

Result delivery mode. Omit this field or use async for polling with statusTask, or use callback for webhook delivery.

string

Required when request_type is callback. Must be a public HTTPS URL that can receive the final task payload. See Webhooks.

object

required

Seedance 2.5 input parameters.

Show properties

string

required

Generation mode. Supported values: text-to-video, first_and_last_frames, omni_reference.

string

required

Text prompt describing the desired video. The API trims whitespace, rejects empty prompts, and does not enforce a maximum prompt length. Prompts with video-editing intent such as edit video, add, remove, modify, replace, change to, 编辑视频, 增加, 加上, 删除, 去掉, 修改, 替换, or 改成 may require duration=-1 and aspect_ratio=auto.

string

default:"720p"

Output resolution. Supported values: 480p, 720p. Values are trimmed and normalized to lowercase.

integer|string

default:"5"

Output duration in seconds. Supports integers from 4 through 30, including numeric strings such as "10", or -1 for dynamic duration. When duration=-1, the request is pre-charged as 30 seconds of output and settled by actual output duration after success.

string

default:"auto"

Output aspect ratio. Supported values: auto, 16:9, 4:3, 1:1, 3:4, 9:16, 21:9. Use auto for first_and_last_frames and for prompts that may trigger video editing.

boolean

default:"true"

Whether to generate audio with the video. Must be a boolean when provided.

string

default:"mp4"

Output container format. Supported values: mp4, mov.

boolean

default:"false"

Whether to add a watermark. Must be a boolean when provided.

boolean

default:"false"

Enables content safety checking for this request. API requests default to false; the APIXO playground may use its own default. Must be a boolean when provided.

string[]

Reference image URLs. Required for first_and_last_frames with 1-2 images. Optional for omni_reference with up to 30 images.

string[]

Reference video URLs for omni_reference. Supports 1-10 URLs when provided. Each video must be 2-30 seconds, and total reference video duration cannot exceed 30 seconds.

string[]

Reference audio URLs for omni_reference. Supports 1-10 URLs when provided. Each audio file must be 2-30 seconds, and total reference audio duration cannot exceed 30 seconds.

Mode	Required media	Optional media	Billing note
`text-to-video`	None	None	Uses the no-video-reference rate.
`first_and_last_frames`	`image_urls` with 1-2 images	None	Uses the no-video-reference rate and requires `aspect_ratio=auto`.
`omni_reference`	At least one of `image_urls`, `video_urls`, or `audio_urls`	Any supported reference media	Uses video-reference billing when `video_urls` is provided.

In omni_reference, audio-only requests are supported. The video-reference rate only applies when video_urls is provided.

Use public, directly accessible URLs for all reference media. Video and audio durations are checked before the task is submitted.

image_urls examples use URL strings. The API also accepts object items with a non-empty url field and normalizes them to URL strings.

Video-editing prompt behavior

Seedance 2.5 can infer a video-editing task from the prompt text. If your prompt asks the model to edit, add, remove, modify, replace, or change parts of an existing video, send the request with:

{
  "duration": -1,
  "aspect_ratio": "auto"
}

This applies even when the public mode is still omni_reference. Examples of prompt terms that can trigger this behavior include edit video, add, add to, delete, remove, modify, replace, change to, 编辑视频, 增加, 加上, 删除, 去掉, 修改, 替换, and 改成.

Response format

Submit task response

POST /generateTask/seedance-2-5 returns a task ID when the task is accepted:

integer

API status code. 200 means the task was accepted.

string

Human-readable status message.

string

Unique task identifier used with the status endpoint.

Status response fields

string

Unique task identifier.

string

Current task state: pending, processing, success, or failed.

string

JSON string containing generated video URLs in resultUrls. Present when state is success.

string

Machine-readable failure code. Present when state is failed.

string

Human-readable failure message. Present when state is failed.

integer

Task creation timestamp in Unix milliseconds.

integer

Task completion timestamp in Unix milliseconds. Present after completion.

integer

Processing duration in milliseconds. Present after completion when timing data is available.

Webhook callback mode

Use callback mode when your backend should receive the final result automatically instead of polling.

curl -X POST "https://api.apixo.ai/api/v1/generateTask/seedance-2-5" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "callback",
    "callback_url": "https://your-server.com/webhooks/apixo",
    "input": {
      "mode": "first_and_last_frames",
      "prompt": "turn the still frames into a smooth cinematic camera move",
      "image_urls": [
        "https://example.com/frame-start.png",
        "https://example.com/frame-end.png"
      ],
      "resolution": "720p",
      "duration": 5,
      "aspect_ratio": "auto",
      "sound": true
    }
  }'

The callback payload uses the same top-level shape as status polling with code, message, and data. Successful callbacks include the final state and resultJson. See Webhooks for delivery requirements and retry behavior.

Billing

Seedance 2.5 is billed per second. The selected resolution and whether omni_reference includes video_urls determine the per-second unit price.

Configuration	APIXO price
`480p`, without video reference	`$0.140 / second`
`480p`, with video reference	`$0.085 / second`
`720p`, without video reference	`$0.315 / second`
`720p`, with video reference	`$0.190 / second`

Formula without video reference:

total cost = output duration * unit price

Formula with video reference:

total cost = (output duration + total reference video duration) * unit price

text-to-video and first_and_last_frames always use the without-video-reference rate. omni_reference uses the with-video-reference rate only when video_urls is provided. When duration=-1, APIXO pre-charges the output portion as 30 seconds. After a successful task, APIXO settles by the actual generated output duration and refunds any overcharged output seconds. If video_urls are provided, reference video seconds are still included in billable seconds. For current route and market comparison pricing, see Pricing.

Latency and polling

Seedance 2.5 tasks are asynchronous. Actual latency may vary by prompt complexity, duration mode, resolution, reference media accessibility, route queue load, and storage transfer time.

Workload	Typical generation time	Recommended first poll	Poll interval
Text-to-video or first-and-last-frames	Varies by prompt, duration, and resolution	120s after task creation	10s-20s
Omni-reference with image/video/audio inputs	Varies by reference count, media duration, and accessibility	180s after task creation	10s-20s

For production workloads, use callback mode to avoid frequent polling while video tasks run.

Result URLs are temporary. Download and store important outputs promptly after task completion. Rate limits and concurrency can vary by account, API key, and route. If you receive 429, slow down requests and retry with backoff. For account-level details, see System APIs.

Errors and troubleshooting

HTTP errors

Code	Meaning	What to do
`400`	Invalid request body, missing `input`, unsupported `mode`, missing `prompt`, invalid `resolution`, invalid `duration`, invalid `aspect_ratio`, invalid boolean value, invalid `output_format`, or invalid media array	Fix the request before retrying
`401`	Missing or invalid API key	Check the `Authorization` header
`402`	Insufficient balance or quota	Add balance or switch account/key
`403`	Key or route cannot access the model	Check permissions and route strategy
`404`	Task not found when polling	Check the `taskId`
`429`	Rate limit or concurrency limit reached	Retry with exponential backoff
`500`	Server error or unknown task failure	Retry with backoff
`502`	Generation service error	Retry with backoff
`504`	Generation timeout	Retry or use callback mode for long-running jobs

Validation notes

Condition	Backend behavior
Missing `input`	Request fails before task creation.
Missing, non-string, or empty `prompt`	Request fails before task creation.
Missing `mode`	Request fails before task creation.
Unsupported `mode`	Request fails before task creation. Supported values are `text-to-video`, `first_and_last_frames`, and `omni_reference`.
Missing `resolution`	Defaults to `720p`.
Unsupported `resolution`	Request fails before task creation. Supported values are `480p` and `720p`.
Missing `duration`	Defaults to `5`.
`duration` outside `4` through `30` and not `-1`	Request fails before task creation.
`duration=-1`	The task is pre-charged as 30 seconds of output duration, then settled by actual output duration after success.
Missing `aspect_ratio`	Defaults to `auto`.
Unsupported `aspect_ratio`	Request fails before task creation.
Video-editing prompt intent with `duration` not set to `-1` or `aspect_ratio` not set to `auto`	The generation task can fail; use `duration=-1` and `aspect_ratio=auto` for these prompts.
`sound`, `watermark`, or `nsfw_checker` is not a boolean	Request fails before task creation.
Unsupported `output_format`	Request fails before task creation. Supported values are `mp4` and `mov`.
`first_and_last_frames` without `image_urls`	Request fails before task creation.
`first_and_last_frames` with more than 2 images	Request fails before task creation.
`first_and_last_frames` with `aspect_ratio` other than `auto`	Request fails before task creation.
`omni_reference` without `image_urls`, `video_urls`, or `audio_urls`	Request fails before task creation.
`omni_reference` with more than 30 images, 10 videos, or 10 audio files	Request fails before task creation.
Reference video or audio shorter than 2 seconds or longer than 30 seconds	Request fails before task creation.
Total reference video duration or total reference audio duration over 30 seconds	Request fails before task creation.

Task failure codes

failCode is generated from APIXO’s mapped generation error. Common values include:

Fail code	Meaning	What to do
`SensitiveContent`	Prompt or input/output content was rejected by safety checks	Change the prompt or reference media
`PromptInvalid`	Prompt was invalid or rejected during generation	Rewrite the prompt and retry
`ImageFormatIncorrect`	Reference image format could not be processed	Use a public, direct image URL in a common image format
`RateLimited`	Rate limit was reached	Retry with exponential backoff
`Timeout`	Generation timeout	Retry later or use callback mode
`StreamError`	A generation service error occurred	Retry with backoff
`Unknown error`	An unmapped failure occurred	Retry with backoff or contact support with the `taskId`

See Error Codes for the full error reference.

​Overview

​Endpoint and authentication

​Copy-paste async quickstart

​Poll for result

​Request body

​Text-to-video

​Dynamic duration

​First-and-last-frames

​Omni-reference

​Parameters

​Video-editing prompt behavior

​Response format

​Submit task response

​Status response fields

​Webhook callback mode

​Billing

​Latency and polling

​Errors and troubleshooting

​HTTP errors

​Validation notes

​Task failure codes

​Related links

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-video

Dynamic duration

First-and-last-frames

Omni-reference

Parameters

Video-editing prompt behavior

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Validation notes

Task failure codes

Related links