HyperFrames is HeyGen's open-source framework for turning HTML, CSS, media and seekable animations into deterministic MP4 videos, summed up in the README as "Write HTML. Render video. Built for agents." A video is defined as an HTML composition with data attributes for timing and tracks (data-start, data-duration, data-track-index), and animation can come from GSAP, CSS, Lottie, Three.js, Anime.js, WAAPI or a custom frame adapter. The README says the renderer seeks each frame in headless Chrome and encodes the result with FFmpeg, so the same input produces the same video, and that an index.html composition plays as-is with no build step. It can be used locally through the CLI (npx hyperframes init, preview, render), with local or Docker rendering, or through AWS Lambda for distributed renders. The repo is organized as packages: the hyperframes CLI, core, engine, producer, studio, player, shader-transitions and aws-lambda. For coding agents, the repo ships 21 skills and plugin packages for Claude Code, Codex, Cursor, Gemini CLI and others, covering workflows such as product-launch videos, PR-to-video, captions and slideshows. A catalog of installable blocks and components (npx hyperframes add) covers transitions, overlays, captions, charts and maps, and frame.md extends a DESIGN.md design spec for video. The README lists Node.js 22+ and FFmpeg as requirements, and compares itself with Remotion, which it says uses React components and a bundler where HyperFrames uses plain HTML. It is released under the Apache 2.0 license, which the README says carries no per-render fees or commercial-use thresholds. Some related pieces are HeyGen-hosted rather than part of the local package: the hyperframes.dev playground, and a hosted MCP connector that the docs describe as a beta requiring a HeyGen account.