Seedance 2.0 Fast API

Overview

Seedance 2.0 Fast is a ByteDance video generation model for fast text-to-video, first-and-last-frame animation, and multimodal reference workflows. Use this page when you are ready to call the API after trying the model in the APIXO playground.

Capability	Value
Model ID	`seedance-2-0-fast`
Modes	`text-to-video`, `first_and_last_frames`, `omni_reference`
Prompt	Required, non-empty text
Resolution	`480p`, `720p`
Duration	4-15 seconds, default `5`
Aspect ratios	`auto`, `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`
Reference images	`first_and_last_frames`: 1-2 images; `omni_reference`: 1-9 images
Reference videos	`omni_reference` only, 1-3 videos, each 2-15 seconds, total up to 15 seconds
Reference audio	`omni_reference` only, 1-3 audio files, each 2-15 seconds, total up to 15 seconds
Audio and search	Optional generated audio and web search controls

Endpoint and authentication

Base URL:

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

Method	Endpoint	Purpose
`POST`	`/generateTask/seedance-2-0-fast`	Submit a generation task
`GET`	`/statusTask/seedance-2-0-fast?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-2-0-fast" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "request_type": "async",
    "input": {
      "mode": "text-to-video",
      "prompt": "a cinematic tracking shot through a rainy neon street",
      "resolution": "720p",
      "duration": 5,
      "aspect_ratio": "16:9",
      "sound": true,
      "web_search": false
    }
  }'

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-2-0-fast?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": 1767965910929,
    "costTime": 300000
  }
}

Failed response:

{
  "code": 200,
  "message": "success",
  "data": {
    "taskId": "task_12345678",
    "state": "failed",
    "failCode": "PromptInvalid",
    "failMsg": "Prompt is invalid or rejected by provider",
    "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 cinematic tracking shot through a rainy neon street",
    "resolution": "720p",
    "duration": 5,
    "aspect_ratio": "16:9",
    "sound": true,
    "web_search": false
  }
}

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": "9:16",
    "sound": true,
    "web_search": false
  }
}

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,
    "web_search": false
  }
}

Parameters

string

default:"async"

required

Result delivery mode. Use async for polling with statusTask, or 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 2.0 Fast 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 value is trimmed and must not be empty.

string

default:"720p"

Output resolution. Supported values: 480p, 720p.

integer

default:"5"

Output duration in seconds. Supports integers from 4 to 15. Numeric strings are accepted and normalized, but integers are recommended.

string

default:"auto"

Output aspect ratio. Supported values: auto, 16:9, 4:3, 1:1, 3:4, 9:16, 21:9.

boolean

default:"true"

Whether to generate audio with the output video.

boolean

default:"false"

Enables web search so the provider can reference current information during generation.

boolean

default:"false"

Enables content safety filtering for this request. Defaults to false; 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 1-9 images.

string[]

Reference video URLs for omni_reference mode only. When provided, supports 1-3 URLs. Each video must be 2-15 seconds, and total reference video duration cannot exceed 15 seconds.

string[]

Reference audio URLs for omni_reference mode only. When provided, supports 1-3 URLs. Each audio file must be 2-15 seconds, and total reference audio duration cannot exceed 15 seconds.

Mode-specific constraints

text-to-video uses the prompt and generation settings only.
first_and_last_frames requires image_urls with 1-2 images. The first image is the starting frame; the second image, when present, is the ending frame.
omni_reference can combine image_urls, video_urls, and audio_urls.
omni_reference requests with only audio_urls, and no images or videos, are rejected.
Reference media must be publicly reachable URLs so the API can fetch or probe them.

Response format

Submit task response

POST /generateTask/seedance-2-0-fast 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 the 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 successful completion or when available from the task log.

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-2-0-fast" \
  -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": "9:16",
      "sound": true,
      "web_search": false
    }
  }'

See Webhooks for delivery requirements and retry behavior.

Billing

Seedance 2.0 Fast is billed per second. The selected resolution and whether omni_reference includes video_urls determine the unit price.

Configuration	APIXO price
`480p`, without video reference	`$0.08 / second`
`480p`, with video reference	`$0.044 / second`
`720p`, without video reference	`$0.16 / second`
`720p`, with video reference	`$0.0953 / second`

Billing formulas:

Without video reference: output duration seconds x per-second rate
With video reference: (output duration seconds + total reference video seconds) x per-second rate

text-to-video and first_and_last_frames always use the “without video reference” rate. In omni_reference mode, “with video reference” applies only when video_urls is provided. Image and audio references do not add extra billable seconds. For current route and market comparison pricing, see Pricing.

Latency and polling

Actual latency may vary by prompt complexity, reference media, provider route, and current queue load.

Workflow	Typical generation time	Recommended first poll	Poll interval
Text-to-video	3-6 minutes	200-300s after task creation	10-20s
First-and-last-frames	3-6 minutes	200-300s after task creation	10-20s
Omni-reference	3-6 minutes	200-300s after task creation	10-20s

For production workloads, use callback mode to reduce polling overhead during longer video tasks.

No visible status change during the first few minutes can be normal for this model. Keep polling with backoff instead of immediately retrying the same task.

Result URLs can be temporary. Download generated videos promptly after task completion.

Errors and troubleshooting

HTTP errors

Code	Meaning	What to do
`400`	Invalid request body, missing parameter, unsupported value, or invalid reference media	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	Check the `taskId` and model endpoint
`429`	Rate limit or concurrency limit reached	Retry with exponential backoff
`500`	Server error or unmapped provider failure	Retry with backoff
`502`	Upstream provider error	Retry with backoff
`504`	Upstream timeout	Retry or use callback mode for long-running jobs

Common request validation errors

Error	Meaning	What to do
`Missing required parameter`	`input`, `mode`, `prompt`, or a mode-specific required field is missing	Add the required field
`Invalid parameter type`	A field has the wrong JSON type	Use strings for text fields and URLs, booleans for `sound` and `web_search`, and integers for `duration`
`Invalid parameter value`	A value is outside the supported set or range	Check `mode`, `resolution`, `duration`, `aspect_ratio`, and reference media durations
`Param length exceeded`	Too many reference URLs were provided	Keep `image_urls`, `video_urls`, and `audio_urls` within the documented limits
`ImageNotAccess`	A referenced URL could not be accessed	Use public, direct media URLs

Task failure codes

Fail code	Meaning	What to do
`PromptInvalid`	Prompt or input was rejected by the provider	Adjust the prompt or references
`SensitiveContent`	Input or output was flagged by safety checks	Change the prompt or input media
`RateLimited`	Provider or account rate limit was reached	Retry with exponential backoff
`Timeout`	Provider timed out	Retry later or use callback mode
`Unknown error`	Provider returned an unmapped failure	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

​First-and-last-frames

​Omni-reference

​Parameters

​Mode-specific constraints

​Response format

​Submit task response

​Status response fields

​Webhook callback mode

​Billing

​Latency and polling

​Errors and troubleshooting

​HTTP errors

​Common request validation errors

​Task failure codes

​Related links

Overview

Endpoint and authentication

Copy-paste async quickstart

Poll for result

Request body

Text-to-video

First-and-last-frames

Omni-reference

Parameters

Mode-specific constraints

Response format

Submit task response

Status response fields

Webhook callback mode

Billing

Latency and polling

Errors and troubleshooting

HTTP errors

Common request validation errors

Task failure codes

Related links