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

# HappyHorse 1.0 Reference to Video

> - HappyHorse 1.0 multi-character reference-to-video model, drives video generation with 1-9 reference images
- Use `@Image1` ~ `@Image9` in the prompt to reference each image
- Supports `720p` / `1080p` output, 3-15 second duration
- Async processing mode, use the returned task ID to [query task status](/pages/en/api-manual/task-management/get-task-detail)
- Generated video links are valid for 24 hours, please save them promptly




## OpenAPI

````yaml openapi/en/happyhorse-1.0-reference-to-video.json POST /v1/videos/generations
openapi: 3.1.0
info:
  title: HappyHorse 1.0 Reference to Video
  version: '1.0'
servers:
  - url: https://api.aihubmax.com
security:
  - BearerAuth: []
paths:
  /v1/videos/generations:
    post:
      tags:
        - Video > HappyHorse
      summary: HappyHorse 1.0 Reference to Video
      description: >
        - HappyHorse 1.0 multi-character reference-to-video model, drives video
        generation with 1-9 reference images

        - Use `@Image1` ~ `@Image9` in the prompt to reference each image

        - Supports `720p` / `1080p` output, 3-15 second duration

        - Async processing mode, use the returned task ID to [query task
        status](/pages/en/api-manual/task-management/get-task-detail)

        - Generated video links are valid for 24 hours, please save them
        promptly
      operationId: happyhorse-1.0-reference-to-video
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/HappyHorseR2VRequest'
            examples:
              single_character_reference:
                summary: Single-character reference
                value:
                  model: happyhorse-1.0-reference-to-video
                  prompt: '@Image1 dancing on a moonlit stage'
                  image_urls:
                    - https://example.com/character.jpg
                  aspect_ratio: '16:9'
                  duration: 5
                  resolution: 1080p
              multi_character_reference:
                summary: Multi-character reference
                value:
                  model: happyhorse-1.0-reference-to-video
                  prompt: '@Image1 and @Image2 training together at sunrise'
                  image_urls:
                    - https://example.com/athlete1.jpg
                    - https://example.com/athlete2.jpg
                  duration: 8
                  resolution: 720p
      responses:
        '200':
          $ref: '#/components/responses/TaskCreated'
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
        '422':
          $ref: '#/components/responses/UnprocessableEntity'
        '429':
          $ref: '#/components/responses/TooManyRequests'
        '500':
          $ref: '#/components/responses/InternalServerError'
        '503':
          $ref: '#/components/responses/ServiceUnavailable'
components:
  schemas:
    HappyHorseR2VRequest:
      type: object
      required:
        - model
        - prompt
        - image_urls
      properties:
        model:
          description: '`happyhorse-1.0-reference-to-video`: reference-image-to-video'
          examples:
            - happyhorse-1.0-reference-to-video
          type: string
          default: happyhorse-1.0-reference-to-video
        prompt:
          description: >
            Video generation prompt. Use `@Image1` ~ `@Image9` to reference each
            image


            **Notes:**

            - Maximum `2500` characters
          maxLength: 2500
          type: string
          example: '@Image1 and @Image2 training together at sunrise'
        image_urls:
          description: |
            List of reference image URLs, 1-9 images

            **Notes:**
            - Supports JPEG / PNG / WEBP
            - Short edge ≥ `400px`
            - Each image up to `10MB`
            - Array order corresponds to `@Image1` ~ `@Image9` in the prompt
          items:
            type: string
          maxItems: 9
          minItems: 1
          type: array
          example:
            - https://example.com/character.jpg
        aspect_ratio:
          default: '16:9'
          description: |
            Output video aspect ratio

            **Options:** `16:9`, `9:16`, `1:1`, `4:3`, `3:4`
          enum:
            - '16:9'
            - '9:16'
            - '1:1'
            - '4:3'
            - '3:4'
          type: string
          example: '16:9'
        duration:
          default: 5
          description: >-
            Output video duration in seconds. Supports integers from `3` to
            `15`.
          maximum: 15
          minimum: 3
          type: integer
          example: 3
        resolution:
          default: 1080p
          description: 'Output video resolution. Options: `720p` or `1080p`.'
          enum:
            - 720p
            - 1080p
          type: string
          example: 720p
        seed:
          anyOf:
            - maximum: 2147483647
              minimum: 0
              type: integer
            - type: 'null'
          default: null
          description: Random seed used to improve result reproducibility.
          example: 123
        enable_safety_checker:
          anyOf:
            - type: boolean
            - type: 'null'
          default: null
          description: >-
            Whether to enable the safety checker. If not provided, the model
            default behavior is used.


            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: true
    TaskResponse:
      type: object
      properties:
        created:
          type: integer
          description: Task creation timestamp
          example: 1757165031
        id:
          type: string
          description: Task ID
          example: task-unified-1757165031-uyujaw3d
        model:
          type: string
          description: Actual model name used
        object:
          type: string
          description: Specific task type
          enum:
            - video.generation.task
        progress:
          type: integer
          description: Task progress percentage (0-100)
          minimum: 0
          maximum: 100
          example: 0
        status:
          type: string
          description: Task status
          enum:
            - pending
            - processing
            - completed
            - failed
          example: pending
        task_info:
          type: object
          description: Asynchronous task information
          properties:
            can_cancel:
              type: boolean
              description: Whether the task can be cancelled
              example: true
            estimated_time:
              type: integer
              description: Estimated completion time in seconds
              example: 45
        type:
          type: string
          description: Task output type
          enum:
            - video
          example: video
    ErrorResponse400:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Invalid request format
            type:
              type: string
              example: invalid_request_error
    ErrorResponse401:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Invalid API key
            type:
              type: string
              example: authentication_error
    ErrorResponse402:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Insufficient account balance
            type:
              type: string
              example: insufficient_quota
    ErrorResponse422:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Parameter validation failed
            type:
              type: string
              example: validation_error
    ErrorResponse429:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Rate limit exceeded
            type:
              type: string
              example: rate_limit_error
    ErrorResponse500:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Internal server error
            type:
              type: string
              example: server_error
    ErrorResponse503:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
              example: Service temporarily unavailable, please try again later
            type:
              type: string
              example: service_unavailable
  responses:
    TaskCreated:
      description: Task created successfully
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/TaskResponse'
    BadRequest:
      description: Invalid request format
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse400'
    Unauthorized:
      description: Unauthorized
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse401'
    PaymentRequired:
      description: Insufficient balance
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse402'
    UnprocessableEntity:
      description: Parameter validation failed
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse422'
    TooManyRequests:
      description: Rate limit exceeded
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse429'
    InternalServerError:
      description: Internal server error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse500'
    ServiceUnavailable:
      description: Service Unavailable
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse503'
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: |
        ## All APIs require Bearer Token authentication ##

        Add to request header:

        `Authorization: Bearer YOUR_API_KEY`

````