Re-stitch the finished trailer master, or copy it for YouTube or X.

Rebuilds the finished MP4 over the finished cuts and the narration and music ALREADY on the job. Generates nothing, so it is how a music bed or a narration track that landed after the finish is folded in. target says where the video is going: site (the default) re-stitches the master as it plays here, at -18.6 LUFS; youtube and x make a COPY of the finished master levelled to -14 LUFS integrated with its true peak at or under -1 dBTP (a final two-pass loudness pass on the copy only: the picture is copied, never re-encoded, and the master itself never changes). A copy is made from the current master; when the master is out of date or being rebuilt, it is rebuilt first and the copy follows. Free: no price and nothing to confirm. The copy's link and its measured loudness are on the read's platformExports (and on the answer's platformExport) once it is ready. ONLY A COMPLETE TRAILER EXPORTS: a 480p preview master is for review, never the deliverable, so a trailer in review is refused with a 409 that says to finish it first. The answer carries warnings, one per flagged take the writer kept (a line not heard or in another character's voice, an opening off its plan). A queued or rendering export short-circuits rather than stacking. Requires Idempotency-Key. Scope: story:write.