> ## 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. # Wan 2.1 VACE Plus - Unified Video Editing Model > [Core Function] Wan 2.1 VACE Plus - Unified Video Editing Model is an older generation image-to-image editing 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 I2I. ## OpenAPI ````yaml /model-api/alibaba/alibaba-v2v.json post /alibaba/wan2.1-vace-plus openapi: 3.1.0 info: description: The video-to-video models API from Alibaba. version: 1.0.0 contact: name: Modellix Support email: support@modellix.ai title: Alibaba Video-to-Video Models API servers: - url: https://api.modellix.ai/api/v1 description: The video-to-video models API from Alibaba. security: - bearerAuth: [] paths: /alibaba/wan2.1-vace-plus: post: summary: Wan 2.1 VACE Plus - Unified Video Editing Model description: >- [Core Function] Wan 2.1 VACE Plus - Unified Video Editing Model is an older generation image-to-image editing 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 I2I. operationId: wan21VacePlusAsync requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/Wan21VacePlusRequest' examples: image_reference: summary: Multi-Image Reference (image_reference) value: function: image_reference prompt: A girl walking through a forest ref_images_url: - https://example.com/ref1.jpg - https://example.com/ref2.jpg obj_or_bg: - obj - bg duration: 5 video_repainting: summary: Video Repainting (video_repainting) value: function: video_repainting prompt: Transform the car into steampunk style video_url: https://example.com/video.mp4 control_condition: depth video_edit: summary: Local Video Editing (video_edit) value: function: video_edit prompt: A lion in a cafe video_url: https://example.com/video.mp4 mask_image_url: https://example.com/mask.png mask_frame_id: 1 mask_type: tracking video_extension: summary: Video Extension (video_extension) value: function: video_extension prompt: A dog skateboarding first_clip_url: https://example.com/first.mp4 last_clip_url: https://example.com/last.mp4 video_outpainting: summary: Video Outpainting (video_outpainting) value: function: video_outpainting prompt: A lady playing violin video_url: https://example.com/video.mp4 top_scale: 1.5 bottom_scale: 1.5 left_scale: 1.5 right_scale: 1.5 responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/AsyncTaskResponse' components: schemas: Wan21VacePlusRequest: type: object required: - function - prompt properties: prompt: type: string description: >- Content description in Chinese or English (1-800 characters). Describes the desired video content or editing effect. Required for all functions minLength: 1 maxLength: 800 example: A girl walking through a forest function: type: string description: >- Video editing function to use. Determines which parameters are required and applicable: (1) image_reference: Generate video from reference images; (2) video_repainting: Apply style transfer to existing video using control conditions; (3) video_edit: Edit specific regions of video using mask; (4) video_extension: Extend video at start/end using frame/clip references; (5) video_outpainting: Expand video canvas boundaries enum: - image_reference - video_repainting - video_edit - video_extension - video_outpainting example: image_reference ref_images_url: type: array description: >- Reference image URLs array. Usage by function: (1) image_reference: 1-3 images required, used as visual references for video generation; (2) video_repainting: max 1 image optional, provides style reference; (3) video_edit: max 1 image optional, provides style reference; (4) other functions: not used. Images must be publicly accessible HTTP/HTTPS URLs minItems: 1 maxItems: 3 items: type: string format: uri example: - https://example.com/ref1.jpg - https://example.com/ref2.jpg obj_or_bg: type: array description: >- Classification for each reference image: 'obj' (object/subject) or 'bg' (background). Only for image_reference function. Array length must match ref_images_url length. Maximum 1 'bg' element allowed. Helps model distinguish between subject references and background style references items: type: string enum: - obj - bg example: - obj - bg video_url: type: string format: uri description: >- Input video URL. Usage by function: (1) video_repainting: required, the video to be repainted; (2) video_edit: required, the video to be edited; (3) video_outpainting: required, the video to expand; (4) video_extension: optional, provides reference style when extending; (5) image_reference: not used. Must be publicly accessible HTTP/HTTPS/OSS URL example: https://example.com/video.mp4 control_condition: type: string description: >- Control condition type for structure preservation. Usage by function: (1) video_repainting: required, determines how video structure is preserved during repainting; (2) video_extension: required when video_url is present, maintains consistency with reference video; (3) video_edit: optional, provides structural guidance for editing; (4) other functions: not used. Options: 'posebodyface' (pose+body+face detection), 'posebody' (pose+body only), 'depth' (depth map), 'scribble' (edge detection), '' (empty string for no extraction) enum: - posebodyface - posebody - depth - scribble - '' example: depth mask_image_url: type: string format: uri description: >- Mask image URL for video_edit function. Defines the region to edit (white=edit, black=keep). Must provide either mask_image_url OR mask_video_url, not both. When using mask_image_url, also specify mask_frame_id to indicate which frame the mask corresponds to. The mask will be propagated to other frames based on mask_type setting example: https://example.com/mask.png mask_video_url: type: string format: uri description: >- Mask video URL for video_edit function. Provides frame-by-frame mask for precise control (white=edit, black=keep). Must provide either mask_image_url OR mask_video_url, not both. Mask video must have the same frame count as the input video. Use this for complex editing that requires different masks for different frames example: https://example.com/mask.mp4 mask_frame_id: type: integer description: >- Frame ID (1-based index) indicating which frame the mask_image_url corresponds to. Only applicable when using mask_image_url in video_edit function. The mask will be propagated from this frame to others based on mask_type. For example, mask_frame_id=1 means the mask corresponds to the first frame of the video. Default is 1 (first frame) minimum: 1 default: 1 example: 1 mask_type: type: string description: >- Mask propagation type for video_edit function. Options: (1) 'tracking': mask follows object movement across frames (recommended for moving objects); (2) 'fixed': mask stays in same position across all frames (recommended for static scenes or background edits). Default is 'tracking' enum: - tracking - fixed default: tracking example: tracking expand_ratio: type: number description: >- Mask expansion ratio for video_edit function (0.0-1.0). Expands the mask boundary to include surrounding areas. 0.0 = no expansion (use exact mask), 1.0 = maximum expansion. Default is 0.05 (5% expansion). Useful for ensuring complete coverage of editing region and avoiding edge artifacts minimum: 0 maximum: 1 default: 0.05 example: 0.1 expand_mode: type: string description: >- Mask expansion mode for video_edit function. Determines how the mask is expanded when expand_ratio > 0. Options: (1) 'hull': convex hull expansion (smooth, rounded boundaries); (2) 'bbox': bounding box expansion (rectangular boundaries); (3) 'original': keep original mask shape while expanding. Default is 'hull'. Use 'hull' for natural objects, 'bbox' for rectangular regions enum: - hull - bbox - original default: hull example: hull first_frame_url: type: string format: uri description: >- First frame image URL for video_extension function. Specifies the starting frame when extending video forward. At least one of first_frame_url/last_frame_url/first_clip_url/last_clip_url must be provided. Use this to define the exact starting point of the extended video. The model will generate smooth transition from this frame example: https://example.com/first_frame.jpg last_frame_url: type: string format: uri description: >- Last frame image URL for video_extension function. Specifies the ending frame when extending video backward. At least one of first_frame_url/last_frame_url/first_clip_url/last_clip_url must be provided. Use this to define the exact ending point of the extended video. The model will generate smooth transition to this frame example: https://example.com/last_frame.jpg first_clip_url: type: string format: uri description: >- First video clip URL for video_extension function. Provides a video segment to use as the starting portion. At least one of first_frame_url/last_frame_url/first_clip_url/last_clip_url must be provided. Use this when you want more control than a single frame can provide. The model will extend naturally from the end of this clip example: https://example.com/first_clip.mp4 last_clip_url: type: string format: uri description: >- Last video clip URL for video_extension function. Provides a video segment to use as the ending portion. At least one of first_frame_url/last_frame_url/first_clip_url/last_clip_url must be provided. Use this when you want more control than a single frame can provide. The model will extend naturally to the beginning of this clip example: https://example.com/last_clip.mp4 top_scale: type: number description: >- Top boundary expansion scale for video_outpainting function (1.0-2.0). 1.0 = no expansion (original height), 2.0 = double the top area. Default is 1.0. Use values > 1.0 to expand the canvas upward. For example, 1.5 means add 50% more canvas space above the original video. The model will generate content to fill the expanded area naturally minimum: 1 maximum: 2 default: 1 example: 1.5 bottom_scale: type: number description: >- Bottom boundary expansion scale for video_outpainting function (1.0-2.0). 1.0 = no expansion (original height), 2.0 = double the bottom area. Default is 1.0. Use values > 1.0 to expand the canvas downward. For example, 1.5 means add 50% more canvas space below the original video. The model will generate content to fill the expanded area naturally minimum: 1 maximum: 2 default: 1 example: 1.5 left_scale: type: number description: >- Left boundary expansion scale for video_outpainting function (1.0-2.0). 1.0 = no expansion (original width), 2.0 = double the left area. Default is 1.0. Use values > 1.0 to expand the canvas leftward. For example, 1.5 means add 50% more canvas space to the left of the original video. The model will generate content to fill the expanded area naturally minimum: 1 maximum: 2 default: 1 example: 1.5 right_scale: type: number description: >- Right boundary expansion scale for video_outpainting function (1.0-2.0). 1.0 = no expansion (original width), 2.0 = double the right area. Default is 1.0. Use values > 1.0 to expand the canvas rightward. For example, 1.5 means add 50% more canvas space to the right of the original video. The model will generate content to fill the expanded area naturally minimum: 1 maximum: 2 default: 1 example: 1.5 size: type: string description: >- Output video resolution in width*height format. Available options: '1280*720' (16:9 landscape, HD), '720*1280' (9:16 portrait, mobile-friendly), '960*960' (1:1 square, social media), '1088*832' (4:3 landscape), '832*1088' (3:4 portrait). Default is '1280*720'. Choose based on your target platform and use case. Applicable to all functions enum: - 1280*720 - 720*1280 - 960*960 - 832*1088 - 1088*832 default: 1280*720 example: 1280*720 duration: type: integer description: >- Video duration in seconds. Fixed at 5 seconds and cannot be modified. The model always generates 5-second videos regardless of this parameter value enum: - 5 default: 5 example: 5 prompt_extend: type: boolean description: >- Enable intelligent prompt rewriting and enhancement. When true (default), the model will automatically optimize and expand your prompt for better results. When false, uses your prompt exactly as provided. Recommended to keep true unless you need precise control over the exact wording. Applicable to all functions default: true example: true seed: type: integer description: >- Random seed for reproducible results (0-2147483647). Using the same seed with identical parameters will produce similar (though not pixel-perfect identical) results. Useful for A/B testing different prompts while keeping other randomness constant. If not specified, a random seed is used each time. Applicable to all functions 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`.' ````