When moving to the Luma Agents API, send type video to one endpoint instead of using legacy routes, and replace callback_url with polling. Use video.start_frame and video.end_frame with generation_id references for extends, forward or backward.

Context: Official Luma docs (Agents API migration): documents the new request envelope agents must adopt. The legacy Dream Machine routes become POST /v1/generations with type video, video_edit, or video_reframe; the operation is selected by type, not by route. keyframes.frame0 and frame1 become video.start_frame and video.end_frame with no type discriminator, and a generation_id in start_frame extends forward while one in end_frame extends backward. There is no callback_url in the Agents API; the flow is submit, poll GET /v1/generations/{id}, download.