Seedance 2.5 Flash Image-to-Video

curl --request POST \
  --url https://api.evolink.ai/v1/videos/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "seedance-2.5-flash-image-to-video",
  "prompt": "The camera slowly zooms in, the scene gradually comes to life",
  "image_urls": [
    "https://example.com/first-frame.jpg"
  ],
  "duration": 5,
  "quality": "720p"
}
'

{
  "created": 1761313744,
  "id": "task-unified-1774857405-abc123",
  "model": "seedance-2.5-flash-image-to-video",
  "object": "video.generation.task",
  "progress": 0,
  "status": "pending",
  "task_info": {
    "can_cancel": false,
    "estimated_time": 165,
    "video_duration": 8
  },
  "type": "video",
  "usage": {
    "billing_rule": "per_second",
    "credits_reserved": 50,
    "user_group": "default"
  }
}

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

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": "insufficient_quota",
    "message": "Insufficient quota. Please top up your account.",
    "type": "insufficient_quota"
  }
}

{
  "error": {
    "code": "model_access_denied",
    "message": "Token does not have access to model: seedance-2.5-flash-image-to-video",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests, please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Internal server error",
    "type": "api_error"
  }
}

POST

videos

generations

curl --request POST \
  --url https://api.evolink.ai/v1/videos/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "seedance-2.5-flash-image-to-video",
  "prompt": "The camera slowly zooms in, the scene gradually comes to life",
  "image_urls": [
    "https://example.com/first-frame.jpg"
  ],
  "duration": 5,
  "quality": "720p"
}
'

{
  "created": 1761313744,
  "id": "task-unified-1774857405-abc123",
  "model": "seedance-2.5-flash-image-to-video",
  "object": "video.generation.task",
  "progress": 0,
  "status": "pending",
  "task_info": {
    "can_cancel": false,
    "estimated_time": 165,
    "video_duration": 8
  },
  "type": "video",
  "usage": {
    "billing_rule": "per_second",
    "credits_reserved": 50,
    "user_group": "default"
  }
}

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

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": "insufficient_quota",
    "message": "Insufficient quota. Please top up your account.",
    "type": "insufficient_quota"
  }
}

{
  "error": {
    "code": "model_access_denied",
    "message": "Token does not have access to model: seedance-2.5-flash-image-to-video",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests, please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Internal server error",
    "type": "api_error"
  }
}

Authorizations

Authorization

string

header

required

##All endpoints require Bearer Token authentication##

Get API Key:

Visit the API Key Management Page to obtain your API Key

Add to request header:

Authorization: Bearer YOUR_API_KEY

Body

application/json

model

enum<string>

default:seedance-2.5-flash-image-to-video

required

Video generation model name

Available options:

seedance-2.5-flash-image-to-video

Example:

"seedance-2.5-flash-image-to-video"

prompt

string

required

Text prompt describing the desired video. Supports both Chinese and English, recommended no more than 500 characters for Chinese or 1000 words for English. Maximum prompt length: 10000 tokens

Note:

This model does not support video_urls or audio_urls input

Example:

"The camera slowly zooms in, the scene gradually comes to life"

image_urls

string<uri>[]

required

Image URL array, 1–2 images

Image count and behavior:

Image Count	Behavior	Role
1 image	First-frame image-to-video	Automatically set as `first_frame`
2 images	First-last-frame image-to-video	1st image → `first_frame`, 2nd image → `last_frame`

Image requirements:

Supported formats: .jpeg, .png, .webp
Aspect ratio (width/height): 0.4 ~ 2.5
Width/height pixels: 300 ~ 6000 px
Max size per image: 30MB
Total request body size must not exceed 64MB
When providing first and last frames, both images can be identical. If aspect ratios differ, the first frame takes priority and the last frame will be automatically cropped to fit
Image URLs must be directly accessible by the server

Required array length: 1 - 2 elements

Example:

["https://example.com/first-frame.jpg"]

duration

integer

default:5

Video duration (seconds), defaults to 5 seconds

Details:

Supports any integer value between 4–30 seconds
Automatic duration (-1) is not supported; passing it returns a 400 parameter error
Duration directly affects billing

Billing rules:

Billed per second; the billable duration is the output duration (duration)

Required range: 4 <= x <= 30

Example:

5

quality

enum<string>

default:720p

Video resolution, defaults to 720p

Options:

480p: Lower clarity, lower cost
720p: Standard clarity, this is the default

Available options:

480p,

720p

Example:

"720p"

aspect_ratio

enum<string>

default:adaptive

Video aspect ratio, image-to-video only supports adaptive

Options:

adaptive: the output aspect ratio follows the first-frame image; you can also omit this field
Fixed ratios such as 16:9 or 9:16 cannot be specified for this model

Available options:

adaptive

Example:

"adaptive"

generate_audio

boolean

default:true

Whether to generate synchronized audio, defaults to true

Options:

true: Video includes synchronized audio at no additional charge
false: Output silent video

Example:

true

callback_url

string<uri>

HTTPS callback URL for task completion

Callback timing:

Triggered when the task is completed or failed
Sent after billing confirmation is complete

Security restrictions:

Only HTTPS protocol is supported
Callbacks to private IP addresses are prohibited (127.0.0.1, 10.x.x.x, 172.16-31.x.x, 192.168.x.x, etc.)
URL length must not exceed 2048 characters

Callback mechanism:

Timeout: 10 seconds
Up to 3 retries after failure (at 1/2/4 seconds after failure respectively)
Callback response body format is consistent with the task query endpoint response format
A 2xx status code is considered successful; other status codes trigger retries

Example:

"https://your-domain.com/webhooks/video-task-completed"

Response

Video generation task created successfully

created

integer

Task creation timestamp

Example:

1761313744

string

Task ID

Example:

"task-unified-1774857405-abc123"

model

string

Actual model name used

Example:

"seedance-2.5-flash-image-to-video"

object

enum<string>

Specific type of the task

Available options:

video.generation.task

progress

integer

Task progress percentage (0-100)

Required range: 0 <= x <= 100

Example:

0

status

enum<string>

Task status

Available options:

pending,

processing,

completed,

failed

Example:

"pending"

task_info

object

Video task details

Show child attributes

type

enum<string>

Output type of the task

Available options:

text,

image,

audio,

video

Example:

"video"

usage

object

Usage and billing information

Show child attributes

Image Series

Video Series

Audio Series

Text Series

Account Management

Task Management

File Management

Seedance 2.5 Flash Image-to-Video

Authorizations

Body

Response