> ## 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. # Grok Imagine Video Extend > [Core Function] Grok Imagine Video Extend continues an existing video, generating additional footage beyond its end. [Strengths] It excels at seamlessly extending a clip with new prompt-guided motion. [Best For] Highly recommended for: lengthening short clips, continuing a scene, and adding follow-on action. [Limitations] Do NOT use the `duration` parameter expecting it to set the total video length; it only controls the length of the appended segment (2-10 seconds). Input video constraints are enforced by the upstream provider. [Routing] Use this model when the user wants to make a video longer. To restyle or modify an existing video, use Video Edit. ## OpenAPI ````yaml /model-api/xai/xai-v2v.json post /xai/grok-imagine-video-extend openapi: 3.1.0 info: description: >- The video-to-video models API from xAI Grok Imagine. Includes prompt-guided video editing and video extension. Tasks are asynchronous: submit, then poll the task endpoint for the result. version: 1.0.0 contact: name: Modellix Support email: support@modellix.ai title: xAI Grok Imagine Video-to-Video Models API servers: - url: https://api.modellix.ai/api/v1 description: The video-to-video models API from xAI Grok Imagine. security: - bearerAuth: [] paths: /xai/grok-imagine-video-extend: post: summary: Grok Imagine Video Extend description: >- [Core Function] Grok Imagine Video Extend continues an existing video, generating additional footage beyond its end. [Strengths] It excels at seamlessly extending a clip with new prompt-guided motion. [Best For] Highly recommended for: lengthening short clips, continuing a scene, and adding follow-on action. [Limitations] Do NOT use the `duration` parameter expecting it to set the total video length; it only controls the length of the appended segment (2-10 seconds). Input video constraints are enforced by the upstream provider. [Routing] Use this model when the user wants to make a video longer. To restyle or modify an existing video, use Video Edit. operationId: grokImagineVideoExtendAsync requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/GrokImagineVideoExtendRequest' examples: basic: summary: Video and prompt value: prompt: The camera continues forward into the tunnel video: https://example.com/input.mp4 with_duration: summary: With extension length value: prompt: The dancer finishes the spin and bows video: https://example.com/input.mp4 duration: 8 responses: '200': description: Task submitted successfully content: application/json: schema: $ref: '#/components/schemas/AsyncTaskResponse' example: code: 0 message: success data: status: pending task_id: task-xai-v2v-002 model_id: xai/grok-imagine-video-extend get_result: method: GET url: https://api.modellix.ai/api/v1/tasks/task-xai-v2v-002 '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '429': $ref: '#/components/responses/TooManyRequests' '500': $ref: '#/components/responses/InternalServerError' components: schemas: GrokImagineVideoExtendRequest: type: object required: - prompt - video description: >- xAI Grok Imagine video extend request. `duration` controls the length of the appended segment, not the total video length. properties: prompt: type: string minLength: 1 description: Text description guiding the extended footage example: The camera continues forward into the tunnel video: type: string minLength: 1 description: Input video URL or base64 data URI example: https://example.com/input.mp4 duration: type: integer minimum: 2 maximum: 10 default: 6 description: >- Length in seconds of the appended segment (not the total video length) example: 8 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 for polling example: task-abc123 model_id: type: string description: Model ID in `provider/model` format example: xai/grok-imagine-video-edit get_result: type: object description: API information to query the task result properties: method: type: string example: GET url: type: string example: https://api.modellix.ai/api/v1/tasks/task-abc123 description: Detailed data about the submitted asynchronous task. ErrorResponse: type: object required: - code - message properties: code: type: integer example: 400 message: type: string example: 'Invalid parameters: parameter ''video'' is required' responses: BadRequest: description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 400 message: 'Invalid parameters: parameter ''video'' is required' Unauthorized: description: Unauthorized - Invalid or missing API Key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 401 message: 'Authentication failed: invalid API key' TooManyRequests: description: Too many requests - Rate limit exceeded headers: X-RateLimit-Limit: description: Maximum requests per minute schema: type: integer example: 100 X-RateLimit-Remaining: description: Remaining quota in current window schema: type: integer example: 0 X-RateLimit-Reset: description: Rate limit window reset time (Unix timestamp) schema: type: integer example: 1704067260 content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 429 message: >- Rate limit exceeded: 100 requests per minute, retry after 60 seconds InternalServerError: description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: code: 500 message: Internal server error securitySchemes: bearerAuth: type: http scheme: bearer description: 'API Key authentication. Format: `Bearer YOUR_API_KEY`.' ````