Grok Imagine Video Extend (URL)

Continue any video by URL using xAI’s Grok Imagine. Provide the public URL of the clip, describe what happens next, and choose how many seconds of new video to add.

This model takes a video_url and works on any video, including output from Grok Imagine Video 1.5 and Grok Imagine Video 1.5 Lite. Grok Imagine 1.5 Fast Video Extend (xai/grok-imagine-video-extend) takes a task_id instead and only accepts tasks from xai/grok-imagine-1.5-fast-video.

Model

xai/grok-imagine-video-api-extend

Pricing

Billed per second of generated video plus a per-second charge for the source video. The per-second tier is decided by the source clip’s resolution.

Source clip resolution	Per generated second	Per source second
480p	$0.025	$0.005
720p	$0.035	$0.005

Example: adding 6 seconds to a 10-second 720p clip costs 6 ×

0.035 + 10 ×

0.005 = $0.26.

Parameters

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	—	What happens in the new seconds
`video_url`	string	Yes	—	Public URL of the clip to continue
`duration`	int	No	`6`	Seconds of new video to add, `2`–`10`

Unknown request fields are rejected rather than ignored.

Example Request

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "xai/grok-imagine-video-api-extend",
    "input": {
      "prompt": "The camera keeps panning right to reveal a mountain range",
      "video_url": "https://example.com/source-clip.mp4",
      "duration": 6
    }
  }'

Response

{
  "code": 200,
  "success": true,
  "data": {
    "task_id": "abc123def456",
    "status": "processing"
  }
}

Volume discounts are available for almost all models. Reach out at contact@unifically.com to discuss custom pricing.

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Model

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Example Request

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