Who makes a clip
In AI Vids an open page of your workspace makes the clips: it claims a queued video, makes each clip in order and stitches the file, so a queued video waits for an open page.
Every open AI Vids page of a workspace watches the queued videos and claims one, with a lease of a few minutes that is renewed while a clip is made. Two tabs never make it twice, and a closed tab hands it on. A browser model paints the clip in the page. A server model is called through the hub by that page's run, which checks the plan and the month's credits.
So a video queued by someone else, such as your AI, waits until somebody has AI Vids open.