> ## 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.

# Veo 3.1 Extend Video Generation

> - VEO 3.1 video extension model, generates continuation segments based on existing videos
 - Fixed extension of 7 seconds, supports generating accompanying audio
- 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-extend.json POST /v1/videos/generations
openapi: 3.1.0
info:
  title: Veo3.1 Video Extension
  version: '1.0'
servers:
  - url: https://api.aihubmax.com
security:
  - BearerAuth: []
paths:
  /v1/videos/generations:
    post:
      tags:
        - Video > Veo3.1
      summary: Veo3.1 Video Extension
      description: >
        - VEO 3.1 video extension model, generates continuation segments based
        on existing videos
         - Fixed extension of 7 seconds, supports generating accompanying audio
        - 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-extend
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Veo31ExtendGenRequest'
            examples:
              standard_video_extension_with_audio:
                summary: Standard video extension with audio
                value:
                  model: veo-3.1-extend
                  prompt: The camera continues to pan across the landscape
                  video_url: https://example.com/input-video.mp4
                  aspect_ratio: '16:9'
                  generate_audio: true
              fast_mode_extension_without_audio:
                summary: Fast mode extension without audio
                value:
                  model: veo-3.1-extend-fast
                  prompt: The character walks further into the forest
                  video_url: https://example.com/scene.mp4
                  generate_audio: false
              extension_with_advanced_options:
                summary: Extension with advanced options
                value:
                  model: veo-3.1-extend
                  prompt: The bird takes flight from the branch
                  video_url: https://example.com/bird-clip.mp4
                  negative_prompt: blurry, low quality
                  auto_fix: true
                  safety_tolerance: 3
      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:
    Veo31ExtendGenRequest:
      type: object
      required:
        - model
        - prompt
        - video_url
      properties:
        model:
          description: |-
            `veo-3.1-extend`: Standard version
            `veo-3.1-extend-fast`: Fast version
          examples:
            - veo-3.1-extend
            - veo-3.1-extend-fast
          type: string
          default: veo-3.1-extend
        prompt:
          description: |
            Text prompt describing the direction of the video extension content

            **Notes:**
            - Supports both Chinese and English
            - Describe continuing actions, scene changes, etc.
          type: string
          example: The camera continues to pan across the landscape
        video_url:
          description: >
            Publicly accessible URL of the input video


            **Notes:**

            - Must be a publicly accessible URL

            - Input video should be `720p` or `1080p`

            - Input video aspect ratio should be `16:9` or `9:16`

            - The system will continue generating 7 seconds of content from the
            end of this video
          type: string
          example: https://example.com/input-video.mp4
        aspect_ratio:
          default: '16:9'
          description: |
            Output video aspect ratio

            **Options:**
            - `16:9` — Landscape (default)
            - `9:16` — Portrait
          type: string
          example: '16:9'
        generate_audio:
          default: true
          description: |
            Whether to generate accompanying audio

            **Notes:**
            - Enabled by default
          type: boolean
          example: true
        auto_fix:
          anyOf:
            - type: boolean
            - type: 'null'
          default: null
          description: |-
            Auto-fix prompt (default true)

            > 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

            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: 3
        negative_prompt:
          anyOf:
            - type: string
            - type: 'null'
          default: null
          description: |-
            Negative prompt, describing elements you do not want to appear

            **Notes:**
            - Separate multiple keywords with commas


            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: blurry, low quality, watermark
        seed:
          anyOf:
            - type: integer
            - type: 'null'
          default: null
          description: |-
            Random seed

            **Notes:**
            - Set a fixed value to reproduce generation results
            - Omit for random


            > Do not pass this parameter unless necessary.
          x-advanced: true
          example: 42
    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: Async task information
          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: Bad Request
      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`

````