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v1

latestOpenAPI 3.1.02026-08-04143345.6 KB
asyncVideoGeneration

Extend video duration

Extend a video by generating additional frames at the beginning or end. The model uses context frames from the input to produce a seamless continuation with consistent motion and audio.

Responds immediately with the job id and created_at timestamp. Poll GET /v2/extend/{id} until the status is completed, then download from result.video_url.

Billed per second, based on the extended portion plus the context frames used from the input video. See Pricing.

post/v2/extend

Headers

Authorizationstring required

API key authentication

Request body

video_uristring required

Input video for extending. See Input Formats for supported formats and codecs.

  • Supported aspect ratios: 16:9 and 9:16
  • Maximum resolution: 3840x2160 (4K)
  • Minimum frame count: 73 (around 3 seconds at 24fps)

The output video preserves the input video's resolution.

promptstring

Description of what should happen in the extended portion of the video.

durationnumber double required

Duration in seconds to extend the video. Minimum 2 seconds, maximum 20 seconds (480 frames at 24fps).

mode'start' | 'end'

Where to extend the video:

  • end (default): Extends the video at the end.
  • start: Extends the video at the beginning.
model'ltx-2-pro' | 'ltx-2-3-pro'

Model to use for video generation.

Deprecated: ltx-2-pro is deprecated. See the LTX-2 Deprecation Notice.

contextnumber double

Advanced parameter: Number of seconds from the input video to use as context for the extension (maximum 20 seconds).

The model uses context frames from the input video to generate a more coherent extension. The sum of context + duration (converted to frames using the input video's FPS) cannot exceed 505 frames (~21 seconds at 24fps). For higher-FPS inputs, the maximum total duration in seconds will be proportionally lower; for lower-FPS inputs, it will be proportionally higher.

If not provided, defaults to maximize available context within the 505 frame limit while respecting the 20-second cap.

Response

Job submitted successfully

idstring required

Unique job identifier. Use this to poll for status.

created_atstring date-time required

ISO 8601 timestamp of when the job was created.