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

# Wanx 2.1 KF2V Plus

> [Core Function] Wanx 2.1 KF2V Plus is a legacy generation model. [Strengths] Delivered strong Chinese-language prompt understanding and regional aesthetic preferences. Maintained for backward compatibility. [Best For] Existing legacy integrations and workflows that strictly depend on this specific model version's quirks. [Limitations] Do NOT use this for new creations. It is a legacy model maintained for backward compatibility. [Routing] Only use if explicitly requested; otherwise use Wan 2.7.



## OpenAPI

````yaml /media-model-api/alibaba/alibaba-i2v.json post /alibaba/wanx2.1-kf2v-plus
openapi: 3.1.0
info:
  description: The image-to-video models API from Alibaba.
  version: 1.0.0
  contact:
    name: Modellix Support
    email: support@modellix.ai
  title: Alibaba Image-to-Video Models API
servers:
  - url: https://api.modellix.ai/api/v1
    description: The image-to-video models API from Alibaba.
security:
  - bearerAuth: []
paths:
  /alibaba/wanx2.1-kf2v-plus:
    post:
      summary: Wanx 2.1 KF2V Plus
      description: >-
        [Core Function] Wanx 2.1 KF2V Plus is a legacy generation model.
        [Strengths] Delivered strong Chinese-language prompt understanding and
        regional aesthetic preferences. Maintained for backward compatibility.
        [Best For] Existing legacy integrations and workflows that strictly
        depend on this specific model version's quirks. [Limitations] Do NOT use
        this for new creations. It is a legacy model maintained for backward
        compatibility. [Routing] Only use if explicitly requested; otherwise use
        Wan 2.7.
      operationId: wanx21KF2vPlusAsync
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Wanx21KF2vPlusRequest'
            examples:
              basic:
                summary: First and last frames
                value:
                  first_frame_url: https://example.com/first.jpg
                  last_frame_url: https://example.com/last.jpg
                  prompt: Smooth transition
              with_effect:
                summary: With video effect
                value:
                  first_frame_url: https://example.com/person.jpg
                  template: hanfu-1
      responses:
        '200':
          description: Task submitted successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AsyncTaskResponse'
components:
  schemas:
    Wanx21KF2vPlusRequest:
      type: object
      required:
        - first_frame_url
      properties:
        prompt:
          type: string
          description: Video content description, will be ignored when using video effects
          minLength: 1
          maxLength: 800
          example: Smooth transition
        first_frame_url:
          type: string
          description: First frame image URL (supports HTTP/HTTPS/Base64)
          example: https://example.com/first.jpg
        last_frame_url:
          type: string
          description: >-
            Last frame image URL (supports HTTP/HTTPS/Base64), not needed when
            using video effects
          example: https://example.com/last.jpg
        negative_prompt:
          type: string
          maxLength: 500
          description: Description of what to avoid in the output.
        template:
          type: string
          description: >-
            Video effect template name (5 single-person effects available), only
            need first_frame_url when using effects
          enum:
            - hanfu-1
            - solaron
            - magazine
            - mech1
            - mech2
          example: hanfu-1
        resolution:
          type: string
          description: Video resolution tier, only supports 720P
          enum:
            - 720P
          default: 720P
          example: 720P
        duration:
          type: integer
          description: Video duration in seconds, fixed value
          enum:
            - 5
          default: 5
          example: 5
        prompt_extend:
          type: boolean
          description: Enable prompt intelligent rewriting
          default: true
          example: true
        seed:
          type: integer
          description: Random seed for reproducibility
          minimum: 0
          maximum: 2147483647
          example: 42
    AsyncTaskResponse:
      type: object
      required:
        - code
        - message
        - data
      properties:
        code:
          type: integer
          description: Response code, 0 indicates success
          example: 0
        message:
          type: string
          description: Response message
          example: success
        data:
          type: object
          required:
            - status
            - task_id
            - model_id
          properties:
            status:
              type: string
              enum:
                - pending
                - processing
              description: Task status
              example: pending
            task_id:
              type: string
              description: Unique task identifier
              example: task-abc123
            model_id:
              type: string
              description: Model ID
              example: model-123
            get_result:
              type: object
              description: API information to query the task result
              properties:
                method:
                  type: string
                  description: HTTP method
                  example: GET
                url:
                  type: string
                  description: Full URL to query the task result
                  example: https://api.modellix.ai/api/v1/tasks/task-abc123
          description: Detailed data about the submitted asynchronous task.
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: 'API Key authentication. Format: `Bearer YOUR_API_KEY`.'

````