Procedural-film is an agent skill that draws a 32-second vertical video

A content team that wants a short vertical film for TikTok, Reels or Shorts usually ends up paying for a video tool or a stock library, or asking an image model for frames the viewer cannot trust. Procedural-film takes a third route: it tells a coding agent how to draw the whole film in vanilla JavaScript, so the output is one MP4 and one HTML player, and the brief carries no media file.

GitHub user kuhnhomeuk-cell published procedural-film at github.com/kuhnhomeuk-cell/procedural-film under the MIT licence. Read from the GitHub REST API: 500 stars and 57 forks, 25 days after the repository was created and 17 days after the author's last push. The repository topped breakout trending with 500 stars in 30 days.

What the skill makes

The reference film is examples/butterfly-life, the life cycle of a monarch butterfly: 17 shots, 32 seconds, 120 beats per minute, 1080 by 1920 at 24 frames per second. The README says the look alternates "hand-inked paper shots and navy blueprint shots". Every frame is drawn on a canvas in vanilla JavaScript, every sound is written in Web Audio, and the final output is one self-contained HTML player plus an MP4 the author exports with ffmpeg.

A separate retro mode draws pixel-art films at 60 frames per second with an emulated NES sound chip, and a game mode ships a NES-style platformer called Claw'd that the agent deploys to the user's own Vercel account. The game examples are the three worked projects the retro mode was built from.

What runs where

The requirements, named in the README: Node.js 20 or newer, ffmpeg on the path, Chromium for Playwright, and an agent that runs skills and dispatches parallel subagents, with Claude Code named as the example. The Vercel CLI is listed as needed only to deploy a game. A user installs the skill by cloning the repository and symlinking skills/procedural-film into the agent's skills folder, which keeps the butterfly example reachable beside it.

Once installed, a user asks the agent for a procedural film on a subject, for example "make a procedural film about the life of a honeybee". The agent reads SKILL.md, writes the planning documents, assigns one subagent per shot to write a scene file of a thousand lines or more, then sends more subagents back to review each shot. The project ships a six-check gate and a render script to rebuild the butterfly film from the repository.

The limits the author names

The README states one honest limit on cost: a film spends a large share of a coding-agent usage plan, because one subagent writes each shot and more subagents review each one. A second limit, implicit in the pipeline, is that the agent cannot watch its own video, so quality has to be checked another way; the butterfly film ships a layout check that finds cut or overlapping text and a speech check that finds mispronounced words.

The author credits Kevin Ngo's "The life of a fruit fly" as the look and editing reference, and names an analysis document in the repository that records what was taken from it.

Source

• kuhnhomeuk-cell/procedural-film on GitHub, MIT