Continue an existing video with a newly generated segment. Supported only on x-ai/grok-imagine-video — x-ai/grok-imagine-video-1.5 returns a 400.

🔴 duration is the length of the added segment, not the total

A 3-second source with duration: 2 yields a 5-second result.

⚠️ video.duration in the response also reports the added segment (2 in that example), not the total length. Billing likewise counts the added segment, matching the upstream's own basis.

⚠️ The source video must be between 2 and 15 seconds; shorter input is rejected upstream.

{
  "model": "x-ai/grok-imagine-video",
  "prompt": "The boat drifts further into the distance",
  "duration": 5,
  "video": {
    "url": "https://…/source.mp4"
  }
}