Velreel
A three agent pipeline that turns a Shopify store into finished video ads. A Writer drafts, a Director grades with a second model so no agent marks its own homework, and a Producer renders image, video, and music. Pay per video, at 84 to 88 percent gross margin.
The build
Writer on Claude; Director on Claude with Gemini as a second-opinion grader; Producer chaining image, video, and music models. A Python pipeline on Fly.io runs the long video-gen jobs; Cloudflare Workers handle the live progress.
The hard part
Keeping quality high without a human in the loop. We solved that with cross model grading gates, and kept the margin healthy on the expensive generative steps.