Extend an existing video

Primary agent path

Use beatra.videos.extend to continue beyond a clip's current endpoint. Use edit instead when the existing timeline itself should change.

1. Upload the local source video.
2. Call beatra.models.list with capability: "video_extend" for current clip limits, final-duration rules, controls, and prices.
3. Describe only the continuation and any required final composition.
4. Submit once with one client_request_id; poll with beatra.tasks.get.

AI guide

Tool arguments

{
  "instruction": "Continue the camera move until the train enters the tunnel",
  "video": { "type": "artifact", "artifact_id": "artifact_source_clip" },
  "direction": "after",
  "resolution": "720p",
  "duration": 12,
  "client_request_id": "vid-extend-opaque-1"
}

direction is required (after continues past the end). duration means the final output duration, including the source clip—not the number of seconds to add.

Models, controls, and cost

Common controls are prompt, negative_prompt, resolution, duration, aspect_ratio, seed, enhance_prompt, and watermark. Use each only according to the selected model's metadata.

Use beatra.models.list as the current source for selectable models, accepted source duration, final-duration range, resolution, derived aspect ratio, defaults, and price inputs. Ensure the final duration is valid for the source; never silently rewrite it.

Task status and recovery

Keep polling the same task while it is queued or running. Retry a lost create response only with identical arguments and the same client_request_id. A new source, instruction, model, or duration requires a new ID.

REST API

Direct protocol integrations use POST /v1/videos/extend. Follow the generated API operation for the complete request contract. Skill + MCP is the recommended integration; REST serves custom applications.