Happy Horse 1.1 API

Complete API reference for Happy Horse 1.1 video generation models by Alibaba.

Model Variants

This API supports three model variants:

Quick Comparison

Supported Aspect Ratios (Text to Video & Reference to Video)

Happy Horse 1.1 Text to Video

Endpoint

POST /api/v1/video/task

Request Parameters

Required

Optional

Example Request

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const response = await fetch('https://api.flaq.ai/api/v1/video/task', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model_name: 'happyhorse-1.1-text-to-video',
    prompt: 'A cat playing with a ball of yarn on a sunny windowsill',
    duration: 5,
    resolution: '1080p',
    aspect_ratio: '16:9',
    seed: 42,
  }),
});

const { data } = await response.json();
const taskId = data.task_id;

Happy Horse 1.1 Image to Video

Request Parameters

Required

Optional

Note: aspect_ratio is not supported for image-to-video. Output framing follows the uploaded first-frame image.

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/video/task', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model_name: 'happyhorse-1.1-image-to-video',
    image_url: 'https://example.com/first-frame.jpg',
    prompt: 'Gentle motion; cinematic lighting',
    duration: 5,
    resolution: '1080p',
    seed: 42,
  }),
});

const { data } = await response.json();
const taskId = data.task_id;

Happy Horse 1.1 Reference to Video

Request Parameters

Required

@ (AT) Reference Placeholders

The @ (AT) reference feature links reference images to the prompt through numbered <<<image_N>>> placeholders. Numbering starts at 1 and follows the order of the images array.

Optional

Reference Image Requirements

• Supported formats: JPEG, JPG, PNG, WEBP
• Maximum file size: 20 MB per image
• Minimum short side: 400 px
• Count: at least 1, up to 9 images

Example Request

javascriptCopy
const response = await fetch('https://api.flaq.ai/api/v1/video/task', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model_name: 'happyhorse-1.1-reference-to-video',
    prompt: 'Subject moves naturally while preserving reference style and appearance',
    duration: 5,
    resolution: '1080p',
    aspect_ratio: '16:9',
    images: [
      'https://example.com/ref-1.jpg',
      'https://example.com/ref-2.jpg',
    ],
    seed: 42,
  }),
});

const { data } = await response.json();
const taskId = data.task_id;

@ (AT) Reference-to-Video Request Example

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const response = await fetch('https://api.flaq.ai/api/v1/video/task', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model_name: 'happyhorse-1.1-reference-to-video',
    prompt: 'Show the person from <<<image_1>>> walking beside the bicycle from <<<image_2>>> through the street in <<<image_3>>>, preserving all reference details',
    duration: 5,
    resolution: '1080p',
    aspect_ratio: '16:9',
    images: [
      'https://example.com/person-reference.jpg',
      'https://example.com/bicycle-reference.jpg',
      'https://example.com/street-reference.jpg',
    ],
    seed: 42,
  }),
});

const { data } = await response.json();
const taskId = data.task_id;

Response Format

Initial Response

jsonCopy
{
  "code": 0,
  "message": "success",
  "data": {
    "task_id": "{task_id}",
    "response_url": "https://api.flaq.ai/api/v1/video/{task_id}",
    "task_status": "submitted"
  }
}

Polling Response

Poll GET /api/v1/video/{taskId} to check status:

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{
  "code": 0,
  "message": "success",
  "data": {
    "task_id": "{task_id}",
    "response_url": "https://api.flaq.ai/api/v1/video/{task_id}",
    "task_status": "succeed",
    "task_status_msg": null,
    "task_result": {
      "videos": [
        {
          "url": "https://example.com/generated-video.mp4"
        }
      ]
    }
  }
}

Status Values

• submitted: Task accepted and waiting to be processed
• processing: Video generation in progress
• succeed: Video generation completed
• failed: Video generation failed

Processing Time

Typical processing time: 2-5 minutes depending on duration and queue load.

Best Practices

1. Describe Motion Clearly: Add subject movement, camera movement, and scene progression to improve video dynamics.
2. Use Short Iterations First: Start with 3-5 second generations to validate prompt direction before running longer clips.
3. Choose the Right Input Image: For image-to-video, use a clear, well-lit first-frame image with a strong subject focus.
4. Curate Reference Images: For reference-to-video, provide consistent, high-quality reference images that clearly represent the subject or style you want to preserve.
5. Reuse Seeds for Variants: Keep the same seed when testing prompt refinements to compare outputs more consistently.
6. Match Ratio to Delivery Channel: Use 16:9 for landscape video, 9:16 for shorts and reels, and 1:1 for square placements.