HappyHorse 1.0 Reference-to-Video
- HappyHorse 1.0 reference-to-video, supports 1–9 reference images plus a text prompt
- Character reference convention: in
prompt, usecharacter1,character2,character3… keywords to reference the images inimage_urlsarray in order - Asynchronous processing mode, use the returned task ID to query status
- Generated video links are valid for 24 hours, please save them promptly
Authorizations
##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_KEYBody
Video generation model name
happyhorse-1.0-reference-to-video "happyhorse-1.0-reference-to-video"
Text prompt, required
Length limits:
- Chinese: up to
2500characters - Non-Chinese: up to
5000characters - Excess content is automatically truncated
Character reference convention (important):
- The prompt must explicitly use
character1,character2,character3... keywords to reference images inimage_urlsin order - The 1st image corresponds to
character1, the 2nd tocharacter2, and so on - Missing explicit references may cause character confusion
"A woman in a red qipao character1, the camera first frames the slim cut of the qipao from a side medium shot, then switches to a low-angle upward shot capturing details as she gracefully lifts her hand to open a folding fan character2, with tasseled earrings character3 swaying lightly as she turns her head."
Reference image URL array, required, 1 ~ 9 images
Image requirements:
- Supported formats: JPEG, JPG, PNG, WEBP
- Resolution: short edge ≥
400px; 720P or higher quality images are recommended (avoid extremely small, blurry, or heavily compressed images) - Recommended aspect ratio: short edge / long edge ≥
0.4, with consistent proportions across images (close to the target video ratio) - File size: ≤
10MBper image - Image URLs must be publicly accessible (HTTP or HTTPS); private OSS, intranet, or authenticated links are not supported
Order: Array order corresponds to character1, character2 ... references in the prompt
1 - 9 elements[
"https://cdn.example.com/girl.jpg",
"https://cdn.example.com/folding-fan.jpg",
"https://cdn.example.com/earrings.jpg"
]Video resolution tier, defaults to 720p
Options:
720p: Standard clarity, this is the default1080p: HD clarity
Billing note: Resolution tier directly affects billing
720p, 1080p "720p"
Video aspect ratio, defaults to 16:9
Options:
16:9(landscape)9:16(portrait)1:1(square)4:33:4
16:9, 9:16, 1:1, 4:3, 3:4 "16:9"
Video duration (seconds), defaults to 5 seconds
Range:
- Integer
3~15 - Duration directly affects billing
3 <= x <= 155
Random seed, default is random
Details:
- Range:
1~2147483647 - A fixed seed reduces parameter-induced variation when iterating on prompts and improves reproducibility
1 <= x <= 214748364742
HTTPS callback URL for task completion
Callback timing:
- Triggered when the task is completed, failed, or cancelled
- 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
2048characters
Callback mechanism:
- Timeout:
10seconds - Up to
3retries after failure (at1/2/4seconds 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
"https://your-domain.com/webhooks/video-task-completed"
Response
Video generation task created successfully
Task creation timestamp
1761313744
Task ID
"task-unified-1761313744-h1r2vef0"
Actual model name used
"happyhorse-1.0-reference-to-video"
Specific type of the task
video.generation.task Task progress percentage (0-100)
0 <= x <= 1000
Task status
pending, processing, completed, failed, cancelled "pending"
Video task details
Output type of the task
text, image, audio, video "video"
Usage and billing information