Tools

Write videos in HTML, CSS and frame-seekable animations, preview them from the CLI and render deterministic MP4s. Comes with agent skills for product launch videos, captions and talking-head re-edits. Maintained by HeyGen; needs Node.js 22+ and FFmpeg.

HeyGen's official video plugin: compose scenes with HTML, CSS and animation and render deterministic MP4s, with skills for promo videos, captions, voiceover and music, and PR walkthrough videos. Needs Node.js 22+ and FFmpeg.

Has the agent build single-file HTML interactive playgrounds: visual controls on one side, live preview on the other, and a prompt to copy back into Claude. Templates for design tuning, data exploration, concept maps, doc annotation, code review and architecture diagrams. By Anthropic.

Bundles a whole web page with its CSS, images, fonts and scripts into a single HTML file that opens offline exactly as it looked, good for archiving pages or handing them to an agent for offline analysis. It does not run JavaScript, so pre-render dynamic pages with a headless browser.

Develops an original visual language for a brand, campaign, publication, site or product. Without looking at contemporary design, it builds ten typography-only HTML directions; once you lock one, it turns it into a production system. Not for routine UI fixes or existing design systems.