> ## Documentation Index
> Fetch the complete documentation index at: https://docs.myrouter.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Seedance 1.5 Pro Image To Video

This is an async API that returns a task\_id. Use the task\_id to call the Get Async Task Result API to retrieve the video generation result. Supports text-to-video, image-to-video (first frame), and image-to-video (first and last frame) generation.

<Tip>
  This is an **async** API that only returns the task\_id of the async task. Use the task\_id to call the [Get Async Task Result API](/docs/models/reference-get-async-task-result) to retrieve the generated result.
</Tip>

## Request Headers

<ParamField header="Content-Type" type="string" required={true}>
  Enum: `application/json`
</ParamField>

<ParamField header="Authorization" type="string" required={true}>
  Bearer authentication format: Bearer \{\{API Key}}.
</ParamField>

## Request Body

<ParamField body="fps" type="integer" default={24}>
  Frame rate (frames per second). Only 24 fps is supported.

  Possible values: `24`
</ParamField>

<ParamField body="seed" type="integer" default={-1}>
  Seed integer for controlling randomness. Range: \[-1, 2^32-1]. -1 means random seed. The same seed with the same request produces similar (but not identical) results.

  Range: \[-1, 4294967295]
</ParamField>

<ParamField body="image" type="string" required={true}>
  The first frame image for image-to-video generation. Can be an image URL or Base64-encoded image. URL must be accessible. Base64 format: data:image/\<format>;base64,\<encoded\_data>. Supported formats: jpeg, png, webp, bmp, tiff, gif. Aspect ratio: (0.4, 2.5). Dimensions: (300, 6000) pixels. Size: \< 30 MB.
</ParamField>

<ParamField body="ratio" type="string" default="adaptive">
  Aspect ratio of the generated video. 'adaptive': For text-to-video, the model intelligently selects the optimal ratio based on the prompt; for image-to-video, the ratio is automatically selected based on the uploaded first frame image.

  Possible values: `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `adaptive`
</ParamField>

<ParamField body="prompt" type="string" required={true}>
  Text prompt describing the expected video content. Supports both Chinese and English. Recommended to be no more than 500 characters. To generate audio with dialogue, place spoken content in double quotes for better audio generation results.
</ParamField>

<ParamField body="duration" type="integer" default={5}>
  Video duration in seconds. Supports specified durations within the \[4, 12] range. Note: Duration affects billing.

  Range: \[4, 12]
</ParamField>

<ParamField body="watermark" type="boolean" default={false}>
  Whether the generated video includes a watermark. true: with watermark. false: without watermark.
</ParamField>

<ParamField body="last_image" type="string">
  The last frame image for first-and-last-frame image-to-video generation. Can be an image URL or Base64-encoded image. Requirements are the same as the image field. When aspect ratios differ, the last frame will be automatically cropped to match the first frame.
</ParamField>

<ParamField body="resolution" type="string" default="720p">
  Video resolution. Seedance 1.5 pro supports 480p and 720p (1080p is not yet supported).

  Possible values: `480p`, `720p`
</ParamField>

<ParamField body="camera_fixed" type="boolean" default={false}>
  Whether to fix the camera position. true: the platform appends a fixed camera instruction to the prompt (results are not guaranteed). false: camera is not fixed.
</ParamField>

<ParamField body="service_tier" type="string" default="default">
  Service tier for processing the request. 'default': online inference mode with lower RPM and concurrency quotas, suitable for latency-sensitive scenarios. 'flex': offline inference mode with higher TPD quota at 50% of the online mode price, suitable for latency-insensitive scenarios.

  Possible values: `default`, `flex`
</ParamField>

<ParamField body="generate_audio" type="boolean" default={true}>
  Whether the generated video includes synchronized audio. true: the video includes automatically generated speech, sound effects, and background music based on the prompt and visual content. false: outputs a silent video.
</ParamField>

<ParamField body="execution_expires_after" type="integer" default={172800}>
  Task timeout threshold in seconds, calculated from the created\_at timestamp. Default: 172800 (48 hours). Range: \[3600, 259200]. Tasks exceeding this time will be automatically terminated and marked as 'expired'.

  Range: \[3600, 259200]
</ParamField>

## Response

<ResponseField name="id" type="string" required={false}>
  Video generation task ID. Use this ID to call the Get Async Task Result API to check the task status and retrieve the generated video URL upon success.
</ResponseField>