> ## 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.

# Veo3.1 Reference-to-Video

> - VEO 3.1 reference-to-video model (split entry by mode)
- Provide 1-3 reference images via `reference_image_urls`, fixed at `8` seconds
- Only Standard and Fast are available; Lite does not support reference images
- 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/veo-3.1-reference-to-video.json POST /v1/videos/generations
openapi: 3.1.0
info:
  title: Veo3.1 Reference-to-Video
  version: '1.0'
servers:
  - url: https://api.aihubmax.com
security:
  - BearerAuth: []
paths:
  /v1/videos/generations:
    post:
      tags:
        - Video > Veo3.1
      summary: Veo3.1 Reference-to-Video
      description: >
        - VEO 3.1 reference-to-video model (split entry by mode)

        - Provide 1-3 reference images via `reference_image_urls`, fixed at `8`
        seconds

        - Only Standard and Fast are available; Lite does not support reference
        images

        - 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: veo-3.1-reference-to-video
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Veo31ReferenceToVideoRequest'
            examples:
              standard_reference_to_video:
                summary: Standard reference-to-video
                value:
                  model: veo-3.1-reference-to-video
                  prompt: A woman walking through a garden
                  reference_image_urls:
                    - https://example.com/ref1.jpg
                  duration: 8
                  resolution: 1080p
                  reference_type: STYLE
              standard_multi_subject_reference:
                summary: Standard multi-subject reference
                value:
                  model: veo-3.1-reference-to-video
                  prompt: >-
                    A lioness watches a highland cow grazing near the edge of a
                    fjord cliff
                  reference_image_urls:
                    - https://example.com/lioness.jpg
                    - https://example.com/cow.jpg
                    - https://example.com/scenery.jpg
                  aspect_ratio: '16:9'
                  duration: 8
                  resolution: 1080p
              fast_reference_to_video:
                summary: Fast reference-to-video
                value:
                  model: veo-3.1-fast-reference-to-video
                  prompt: Subject runs through a neon-lit street at night
                  reference_image_urls:
                    - https://example.com/character.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:
    Veo31ReferenceToVideoRequest:
      type: object
      required:
        - model
        - prompt
        - reference_image_urls
      properties:
        model:
          description: |-
            `veo-3.1-reference-to-video`: Standard reference-to-video
            `veo-3.1-fast-reference-to-video`: Fast version
          examples:
            - veo-3.1-reference-to-video
            - veo-3.1-fast-reference-to-video
          type: string
          default: veo-3.1-reference-to-video
        prompt:
          description: |
            Text prompt describing the desired video content

            **Notes:**
            - Supports both Chinese and English
          type: string
          example: A woman walking through a garden
        reference_image_urls:
          description: >
            List of reference image URLs


            **Notes:**

            - Quantity: `1` - `3` images

            - Multiple reference images are used for character / style
            consistency
          items:
            type: string
          maxItems: 3
          minItems: 1
          type: array
          example:
            - https://example.com/ref1.jpg
        aspect_ratio:
          default: '16:9'
          description: |
            Output video aspect ratio

            **Options:**
            - `16:9` — Landscape (default)
            - `9:16` — Portrait
          type: string
          example: '16:9'
        duration:
          default: 8
          description: |
            Output video duration (seconds)

            **Notes:**
            - Reference-to-video is fixed at `8` seconds
          type: integer
          example: 8
        resolution:
          default: 1080p
          description: |
            Output video resolution

            **Options:**
            - `720p` — Standard definition
            - `1080p` — High definition (default)
            - `4k` — 4K Ultra HD
          type: string
          example: 720p
        generate_audio:
          default: false
          description: |
            Whether to generate accompanying audio

            **Notes:**
            - Disabled by default
          type: boolean
          example: true
        auto_fix:
          anyOf:
            - type: boolean
            - type: 'null'
          default: null
          description: |-
            Auto-fix prompt; both model variants support this field.

            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: true
        safety_tolerance:
          anyOf:
            - maximum: 6
              minimum: 1
              type: integer
            - type: 'null'
          default: null
          description: >-
            Content safety level, `1` is the strictest, `6` is the most
            permissive.


            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: 3
        enhance_prompt:
          anyOf:
            - type: boolean
            - type: 'null'
          default: null
          description: |-
            Automatically enhance the prompt

            **Model differences:**
            - Only available for `veo-3.1-reference-to-video`
            - Not applicable for `veo-3.1-fast-reference-to-video`


            > Do not pass this parameter unless necessary.
          x-advanced: true
          x-unsupported-models:
            - veo-3.1-fast-reference-to-video
          example: true
        person_generation:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          description: |-
            Person generation control

            **Options:** `dont_allow` / `allow_adult`

            **Model differences:**
            - Only available for `veo-3.1-reference-to-video`
            - Not applicable for `veo-3.1-fast-reference-to-video`


            > Do not pass this parameter unless necessary.
          x-advanced: true
          x-unsupported-models:
            - veo-3.1-fast-reference-to-video
          example: allow_adult
        reference_type:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          description: |-
            Reference image type

            **Options:** `ASSET` / `STYLE`

            **Model differences:**
            - Only available for `veo-3.1-reference-to-video`
            - Not applicable for `veo-3.1-fast-reference-to-video`


            > Do not pass this parameter unless necessary.
          x-advanced: true
          x-unsupported-models:
            - veo-3.1-fast-reference-to-video
          example: STYLE
    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 info
          properties:
            can_cancel:
              type: boolean
              description: Whether the task can be cancelled
              example: true
            estimated_time:
              type: integer
              description: Estimated completion time (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 temporarily 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`

````