Motion Video Kit is a Claude Code skill for launch-style business commercials, with an independent critic loop that reviews every render

A video commercial written by one agent and judged by the same agent will approve its own shots that look wrong, and the problem is only visible once a client watches it on a phone. Motion Video Kit, an open-source Claude Code skill at echris6/motion-video-kit, splits the two jobs: a separate fresh critic agent reviews each render against measurable targets, and only shots that clear the loop go into the cut.

The MIT-licensed repository reached 990 stars and 92 forks within a week of its first public commit on 2026-09-27, according to its GitHub page. It is positioned for people writing launch-style commercials for real businesses, with HTML and GSAP motion, selective Three.js, and AI-generated footage.

The Gauntlet loop

The author describes the central idea as "builder is not judge". Every render goes to a fresh critic agent with no memory of the writing process, which checks the actual output rather than the plan behind it. Each shot is verified against a ledger of measurable targets: frozen-time windows for product reveal shots, loudness in LUFS, contrast ratios, and brand-colour compliance. The repository ships critic prompts for component review, full-film review, verification and storyboard checks.

The author studied 28 reference launch films from established SaaS brands and recorded the pacing, pattern and sound choices in references/motion-grammar.md and references/launch-film-notes.md. The grammar is six rules and a catalog of 16 reusable motion mechanisms. The reference films themselves are linked, not redistributed; the repository holds the written analysis only.

Two worked examples

The kit was built while making two full commercials, both included as case studies. The first is a calm service film at references/case-study-alder.md. The second is a 40-second Three.js product-spec ad for a foldable phone at references/case-study-duo.md, in which every frame is code: measured angle keys for the hinge, a monotone cubic for the fold motion, a locked camera, deterministic accumulation motion blur, and screen continuity through the fold. The author describes both as taking dozens of rounds of independent critique to reach a quality a client would accept.

The scripts folder carries the measurement tools the loop depends on: frozen-time analysis, loudness measurement with ebur128, contact sheets for comparison, sound-effect softening, and an offline mix. The templates folder has an isolated component lab for shot development and a projected-overlays module for 3D callouts.

The kit works best with HyperFrames for rendering, the author says, but the principles, prompts and quality checks are renderer-agnostic. For other models, the author recommends pasting business-motion-film/SKILL.md plus the needed reference files into the context.

The repository also carries a business playbook: verticals with buying evidence, price anchors, a pilot-offer template, and honesty rules. The author says reference-film reach numbers quoted inside are the originating studios' own claims and that the September 2026 market prices should be re-verified before use. The skill enforces labelling and never presents AI-generated imagery as a real customer or job.

Source

Primary source: motion-video-kit on GitHub.