HappyHorse 1.0 - First Frame Image to Video

happyhorse_1.0_i2v

HappyHorse 1.0 First Frame Image to Video generates smooth video from a first-frame image and an optional text prompt.

Endpoints

POST /v1/queue/happyhorse_1.0_i2v # Create task

GET /v1/queue/happyhorse_1.0_i2v/requests/{request_id}/status # Check status

GET /v1/queue/happyhorse_1.0_i2v/requests/{request_id}/response # Get result

PUT /v1/queue/happyhorse_1.0_i2v/requests/{request_id}/cancel # Cancel task

Request parameters

curl --location "https://cloud.seaart.ai/model/v1/queue/happyhorse_1.0_i2v" \
  --header "Authorization: Bearer YOUR_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
    "prompt": "A red apple slowly rotating on a white table, clean studio lighting, static camera.",
    "media": [
      {
        "type": "first_frame",
        "url": "https://image.cdn2.seaart.me/2026-06-01/d8ejq1de878c739e2lrg/995ff4fe1eeec10a06c3c7a172862733.webp"
      }
    ],
    "duration": 5,
    "resolution": "720P"
  }'

prompt string required

Text prompt describing the generated video content. Chinese and English are supported, for example The horse starts running forward through the field. The maximum length is 2500 Chinese characters or 5000 non-Chinese characters, and content beyond the limit is truncated automatically.

media array required

Input media array. Provide exactly one first-frame image.

type string required

Media type, fixed to first_frame.

url string required

First-frame image URL or Base64-encoded image data.

Image requirements:

Supported formats: JPEG, JPG, PNG, WEBP

Width and height: both at least 300 pixels

Aspect ratio: 1:2.5 to 2.5:1

File size: up to 20MB

Input format:

Publicly accessible HTTP or HTTPS URL

Base64 format: data:<MIME_type>;base64,<base64_data>

MIME types: JPEG/JPG use image/jpeg, PNG uses image/png, and WEBP uses image/webp.

Use a publicly accessible URL such as https://example.com/first-frame.jpg.

duration int

Video duration in seconds. Billing is based on successfully generated output video seconds, so this parameter affects cost.

Range: 3 - 15

Default: 5

resolution string

Video resolution. Different resolution tiers use different unit prices, so this parameter affects billing cost.

Options: 720P, 1080P

Default: 1080P

seed int

Random seed. If omitted, the system generates a random seed automatically. Use the same seed across repeated calls to improve reproducibility.

Range: 0 - 2147483647

watermark bool

Whether to add a watermark to the lower-right corner of the generated video. The fixed watermark text is Happy Horse.

Options: true, false

Default: true

Response parameters

{
  "request_id": "mmsu_01hxyz...",
  "response_url": "https://cloud.seaart.ai/model/v1/queue/happyhorse_1.0_i2v/requests/mmsu_01hxyz.../response",
  "status_url": "https://cloud.seaart.ai/model/v1/queue/happyhorse_1.0_i2v/requests/mmsu_01hxyz.../status",
  "cancel_url": "https://cloud.seaart.ai/model/v1/queue/happyhorse_1.0_i2v/requests/mmsu_01hxyz.../cancel",
  "queue_position": 0
}

Field	Type	Description
`request_id`	string	Task ID used for all follow-up operations.
`response_url`	string	URL to fetch the final result.
`status_url`	string	URL to query task status.
`cancel_url`	string	URL to cancel the task.
`queue_position`	int	Current queue position.

Follow-up operations

Check status

Get result

Cancel task

Error handling