## Problem I reproduced the selected open issue batch one by one and confirmed the reports were valid. The fixes all touch the CLI/runtime capture boundary, then the follow-up regression run exposed one over-broad runtime change in sub-composition host visibility and one CI-only baseline trap. Closes #590, #589, #588, #587, #586, and #584. ## What this fixes ### CLI/runtime edge cases - Makes the GSAP infinite-repeat lint rule ignore JavaScript comments, so literal `repeat:-1` text in comments is not flagged. - Lets the compositions CLI inspect `<template>` content, count visual-only template descendants, estimate simple GSAP durations, and suppress root `data-start` warnings in sub-composition lint mode. - Preserves runtime bootstrap scripts when body scripts are coalesced, and injects the runtime into a real `<head>` when source HTML has no head. - Keeps #589 fixed by loading and rendering template-wrapped sub-composition content, while restoring host visibility to the shorter of the authored parent clip window and the child composition live timeline. - Resolves snapshot/validate viewport size from root `data-width` / `data-height` instead of falling back to 1920x1080. - Skips fully off-frame text boxes during contrast sampling and bounds-checks ring samples so contrast output no longer emits `null:1` / `NaN:1`. - Marks muted videos as `data-has-audio="false"` in the core timing compiler, which fixes the same-src muted `<video>` + separate `<audio>` StaticGuard case. - Keeps user-authored `hf-seek` listeners reachable during capture by preventing author scripts from being merged into the runtime bootstrap path. ### Shared helper cleanup - Removes the stale producer-local timing compiler duplicate; producer compilation now consumes the core timing compiler. - Centralizes HTML document helpers in core: fragment parsing, embedded runtime stripping, head/body script injection, and early-head injection. - Centralizes the CLI layout/snapshot static HTML server. - Adds browser-safe core subpath helpers for Lottie readiness and CLI screenshot clip calculation; Studio's Vite config keeps the screenshot clip helper self-contained so clean-checkout test startup does not value-import core `.ts` source. - Replaces the engine parity-contract copy with a core re-export. - De-duplicates render-job cleanup and Studio static file-serving callbacks. ### Regression hardening - Replaces the embedded-runtime script stripping regex with a script-tag scanner that handles closing tags like `</script >`. - Escapes inline script bodies before wrapping them in `<script>` tags, so authored `</script` and `<!--` text cannot break out of the injected wrapper script. - Shares media-duration clamping between core and producer, with a 50 ms tolerance for ffprobe precision drift between local and CI media stacks. - Pins the affected style fixture SFX durations in source so style-1 and style-9 compile deterministically. - Restores the `vfr-screen-recording` video golden to the CI-stable baseline; the current CI failure showed the Linux render matches the old golden, while the locally refreshed macOS golden was the mismatch. ## Root cause The CLI paths had accumulated assumptions that held for simple direct-root landscape compositions but not for current composition patterns: DOM queries did not enter template content, snapshot/validate used a fixed viewport, runtime and author scripts shared a coalescing bucket, and timing compilation treated every video as audio-bearing unless authors manually overrode it. The style shard failures were not product regressions. Local and CI media probing disagreed on the short SFX clip duration by about 45 ms, and the compiler was clamping authored durations to the locally probed value. The shared clamp tolerance preserves explicit author/source durations for small probe precision differences while still clamping real overflows. The vfr fast-shard failure was a bad baseline refresh: CI actual frames matched the old `vfr-screen-recording` baseline at 40+ dB PSNR, but mismatched the macOS-refreshed golden at ~18-22 dB. The fix is to keep the Docker/Linux-stable video golden and only retain the deterministic compiled snapshot change. The sub-composition regression came from treating a host's authored parent window as the only visibility boundary. That made settled child overlays stay visible after their own live GSAP timeline ended. The corrected runtime behavior respects both contracts: parent clips still bound where the host can appear, and the child live timeline can end the host earlier. ## Verification ### Local checks - `bunx oxfmt --check packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts` - `bunx oxlint packages/core/src/runtime/init.ts packages/core/src/runtime/init.test.ts` - `bun run --cwd packages/core test src/runtime/init.test.ts` - `bun run --cwd packages/cli test src/commands/compositions.test.ts src/utils/compositionViewport.test.ts` - `bun run build:hyperframes-runtime` - `bun run --cwd packages/producer test --keep-temp --sequential style-12-prod style-5-prod` - `bun run --cwd packages/producer test --sequential vfr-screen-recording hdr-hlg-regression style-7-prod` - `bun run --cwd packages/core test src/compiler/htmlCompiler.test.ts src/compiler/timingCompiler.test.ts src/index.test.ts` - `bunx oxfmt --check packages/core/src/compiler/timingCompiler.ts packages/core/src/compiler/htmlCompiler.ts packages/core/src/compiler/htmlCompiler.test.ts packages/core/src/compiler/index.ts packages/core/src/index.ts packages/core/src/index.test.ts packages/producer/src/services/htmlCompiler.ts` - `bunx oxlint packages/core/src/compiler/timingCompiler.ts packages/core/src/compiler/htmlCompiler.ts packages/core/src/compiler/htmlCompiler.test.ts packages/core/src/compiler/index.ts packages/core/src/index.ts packages/core/src/index.test.ts packages/producer/src/services/htmlCompiler.ts` - `bun run --cwd packages/core typecheck` - `bun run --cwd packages/producer typecheck` - `bun run --cwd packages/producer test --sequential style-1-prod style-9-prod` - `bun run --filter @hyperframes/studio test` with `packages/core/dist` temporarily hidden to simulate clean-checkout config loading - `git diff --check` ### CI artifact checks - Inspected failed run `25225854394` job `73969147096`: style-1 failed only on `click-sfx` `1.044898` vs `1` duration/end. - Inspected failed run `25225854394` job `73969147061`: style-9 failed only on SFX `1.044898`-based duration/end mismatches. - Inspected failed run `25225854394` job `73969147048`: `vfr-screen-recording` compilation/audio passed, visual failed after comparing against the macOS-refreshed golden. - Compared the first 10 uploaded CI vfr failure frames against the restored old baseline; minimum PSNR was `40.444705`, above the fixture threshold of `28`. ### Repro checks - `bun packages/cli/src/cli.ts lint /tmp/hf-590-repro` now passes without `gsap_infinite_repeat`. - `bun packages/cli/src/cli.ts snapshot /tmp/hf-587-repro --at 0.5 --timeout 1000` now writes a 1080x1920 PNG. - `bun packages/cli/src/cli.ts validate /tmp/hf-588-repro --timeout 500` no longer emits `null:1` / `NaN:1` contrast output. - `bun packages/cli/src/cli.ts validate /tmp/hf-586-repro --timeout 500 --contrast false` no longer emits the muted-video StaticGuard contract error. - `bun packages/cli/src/cli.ts compositions /tmp/hf-589-gsap-repro` now reports `foo 0.5s 1920x1080 1 element`. - `bun packages/cli/src/cli.ts snapshot /tmp/hf-589-gsap-repro --at 0.25 --timeout 2000` captures the expected template-backed red frame. - `bun packages/cli/src/cli.ts snapshot /tmp/hf-584-repro --at 0.5,1.5 --timeout 500` captures the expected post-seek green frame. ### Browser verification - Refreshed the local side-by-side comparison page at `qa-artifacts/pr-591-video-compare/index.html`. - Served the comparison page locally and used `agent-browser` to load `style-12-prod`, play both videos quickly to the failed window, pause, and inspect the side-by-side frame. - Browser proof screenshot: `qa-artifacts/pr-591-video-compare/browser-proof/fixed-style12-labeled.png`. - Browser proof recording: `qa-artifacts/pr-591-video-compare/browser-proof/fixed-style12.webm`. - Earlier Studio proof artifacts remain local-only: `qa-artifacts/dedupe-refactor-preview.png`, `qa-artifacts/dedupe-refactor-preview-after-play.png`, `qa-artifacts/dedupe-refactor-preview.webm`. ## Notes - Browser proof and CI diagnostic artifacts are intentionally local-only and not committed. - Studio's Vite config intentionally keeps the thumbnail clip helper inline because Vite/Vitest config startup runs through Node's loader before package source `.ts` imports are transformed. - The committed PR diff changes `vfr-screen-recording/output/compiled.html` but no longer changes `vfr-screen-recording/output/output.mp4` relative to `main`. - I attempted a local `linux/amd64` Docker validation to mirror CI, but the local Docker build was blocked by Debian package download failures. The arm64 Docker image also cannot launch the x64 Puppeteer headless shell under OrbStack. The vfr baseline decision is therefore based on the uploaded CI artifact comparison above. - I kept this validated issue batch in one PR because the fixes overlap the same CLI/runtime capture surfaces.
Write HTML. Render video. Built for agents.
Hyperframes is an open-source video rendering framework that lets you create, preview, and render HTML-based video compositions — with first-class support for AI agents.
Quick Start
Option 1: With an AI coding agent (recommended)
Install the HyperFrames skills, then describe the video you want:
npx skills add heygen-com/hyperframes
This teaches your agent (Claude Code, Cursor, Gemini CLI, Codex) how to write correct compositions, GSAP timelines, Tailwind v4 browser-runtime styles, and first-party adapter animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for CLI commands, /tailwind for init --tailwind projects, /gsap for timeline animation help, or the adapter skills (/animejs, /css-animations, /lottie, /three, /waapi) when a composition uses those runtimes.
For Claude Design, open docs/guides/claude-design-hyperframes.md on GitHub and click the download button (↓) to save it, then attach the file to your Claude Design chat. It produces a valid first draft; refine in any AI coding agent. See the Claude Design guide.
For Open Design — the open-source, BYOK alternative to Claude Design that runs locally and drives whichever coding-agent CLI you already have on your PATH — open docs/guides/open-design-hyperframes.md and either drop it into your project's skills/hyperframes-handoff/SKILL.md or attach it to your Open Design chat. It teaches Open Design to emit a HyperFrames-valid composition; refine in any AI coding agent. See the Open Design guide.
For Codex specifically, the same skills are also exposed as an OpenAI Codex plugin — sparse-install just the plugin surface:
codex plugin marketplace add heygen-com/hyperframes --sparse .codex-plugin --sparse skills --sparse assets
For Claude Code, the repo also ships a Claude Code plugin manifest: test it locally with claude --plugin-dir .. The manifest intentionally omits skills because Claude Code auto-discovers the root skills/ directory by convention, and for marketplace submission use the title HyperFrames by HeyGen plus the black/white icon assets at assets/claude-code-icon-dark.svg and assets/claude-code-icon-light.svg for the two theme slots.
For Cursor, the same skills are packaged as a Cursor plugin — install from the Cursor Marketplace, or sideload by cloning this repo and pointing Settings → Plugins → Load unpacked at the repo root.
Try it: example prompts
Copy any of these into your agent to get started. The /hyperframes prefix loads the skill context explicitly so you get correct output the first time.
Cold start — describe what you want:
Using
/hyperframes, create a 10-second product intro with a fade-in title, a background video, and background music.
Warm start — turn existing context into a video:
Take a look at this GitHub repo https://github.com/heygen-com/hyperframes and explain its uses and architecture to me using
/hyperframes.
Summarize the attached PDF into a 45-second pitch video using
/hyperframes.
Turn this CSV into an animated bar chart race using
/hyperframes.
Format-specific:
Make a 9:16 TikTok-style hook video about [topic] using
/hyperframes, with bouncy captions synced to a TTS narration.
Iterate — talk to the agent like a video editor:
Make the title 2x bigger, swap to dark mode, and add a fade-out at the end.
Add a lower third at 0:03 with my name and title.
The agent handles scaffolding, animation, and rendering. See the prompting guide for more patterns.
Option 2: Start a project manually
npx hyperframes init my-video
cd my-video
npx hyperframes preview # preview in browser (live reload)
npx hyperframes render # render to MP4
hyperframes init installs skills automatically, so you can hand off to your AI agent at any point.
Requirements: Node.js >= 22, FFmpeg
Why Hyperframes?
- HTML-native — compositions are HTML files with data attributes. No React, no proprietary DSL.
- AI-first — agents already speak HTML. The CLI is non-interactive by default, designed for agent-driven workflows.
- Deterministic rendering — same input = identical output. Built for automated pipelines.
- Frame Adapter pattern — bring your own animation runtime (GSAP, Lottie, CSS, Three.js).
Hyperframes vs Remotion
Hyperframes is inspired by Remotion — we used Remotion at HeyGen in production, learned a ton from it, and kept attribution comments in the source for the patterns it pioneered (Chrome launch flags, image2pipe → FFmpeg streaming, frame buffering). Both tools drive headless Chrome and both are deterministic. They differ on one decision: what the primary author writes. Remotion's bet is React components; Hyperframes' bet is HTML.
| Hyperframes | Remotion | |
|---|---|---|
| Authoring | HTML + CSS + GSAP | React components (TSX) |
| Build step | None; index.html plays as-is |
Required (bundler) |
| Library-clock animations (GSAP, Anime.js, Motion One) | Seekable, frame-accurate | Plays at wall-clock during render |
| Arbitrary HTML / CSS passthrough | Paste and animate | Rewrite as JSX |
| Distributed rendering | Single-machine today | Lambda, production-ready |
Licensing: fully open source vs source-available
Hyperframes is completely open source under Apache 2.0 — an OSI-approved license. Use it commercially at any scale, with no per-render fees, no seat caps, no company-size thresholds.
Remotion is source-available, not open source. The code is on GitHub under a custom Remotion License that requires a paid company license above small-team thresholds. It's a great product with a real team behind it — but if open-source licensing matters to you (OSI compliance, redistribution rights, no per-use fees), that's a first-order decision point.
Full write-up with benchmarks, an honest list of where each tool wins, and a GSAP side-by-side: Hyperframes vs Remotion guide.
How It Works
Define your video as HTML with data attributes:
<div id="stage" data-composition-id="my-video" data-start="0" data-width="1920" data-height="1080">
<video
id="clip-1"
data-start="0"
data-duration="5"
data-track-index="0"
src="intro.mp4"
muted
playsinline
></video>
<img
id="overlay"
class="clip"
data-start="2"
data-duration="3"
data-track-index="1"
src="logo.png"
/>
<audio
id="bg-music"
data-start="0"
data-duration="9"
data-track-index="2"
data-volume="0.5"
src="music.wav"
></audio>
</div>
Preview instantly in the browser. Render to MP4 locally or in Docker.
Catalog
50+ ready-to-use blocks and components — social overlays, shader transitions, data visualizations, and cinematic effects:
npx hyperframes add flash-through-white # shader transition
npx hyperframes add instagram-follow # social overlay
npx hyperframes add data-chart # animated chart
Browse the full catalog at hyperframes.heygen.com/catalog.
Documentation
Full documentation at hyperframes.heygen.com/introduction — Quickstart | Guides | API Reference | Catalog
Packages
| Package | Description |
|---|---|
hyperframes |
CLI — create, preview, lint, and render compositions |
@hyperframes/core |
Types, parsers, generators, linter, runtime, frame adapters |
@hyperframes/engine |
Seekable page-to-video capture engine (Puppeteer + FFmpeg) |
@hyperframes/producer |
Full rendering pipeline (capture + encode + audio mix) |
@hyperframes/studio |
Browser-based composition editor UI |
@hyperframes/player |
Embeddable <hyperframes-player> web component |
@hyperframes/shader-transitions |
WebGL shader transitions for compositions |
Skills
HyperFrames ships skills that teach AI agents framework-specific patterns that generic docs don't cover.
npx skills add heygen-com/hyperframes
| Skill | What it teaches |
|---|---|
hyperframes |
HTML composition authoring, captions, TTS, audio-reactive animation, transitions |
hyperframes-cli |
CLI commands: init, lint, preview, render, transcribe, tts, doctor |
hyperframes-registry |
Block and component installation via hyperframes add |
website-to-hyperframes |
Capture a URL and turn it into a video — full website-to-video pipeline |
remotion-to-hyperframes |
Translate a Remotion (React) composition into a HyperFrames HTML composition |
gsap |
GSAP timelines for HyperFrames: paused registration, deterministic seeking, easing, sequencing, performance |
animejs |
Anime.js animations and timelines registered on window.__hfAnime for deterministic HyperFrames seeking |
css-animations |
CSS keyframe animation patterns that HyperFrames can discover, pause, and seek |
lottie |
lottie-web and dotLottie players registered on window.__hfLottie with local assets and paused playback |
three |
Three.js scenes that render from HyperFrames hf-seek events and window.__hfThreeTime instead of wall-clock time |
waapi |
Web Animations API element.animate() patterns seeked through document.getAnimations() |
Contributing
See CONTRIBUTING.md for guidelines.
Cloning the repo
The repo uses Git LFS for golden regression-test baselines under packages/producer/tests/**/output.mp4 (~240 MB of .mp4 files). If you're cloning the full repo for development, install Git LFS first:
# macOS
brew install git-lfs
# Ubuntu/Debian
sudo apt install git-lfs
# Windows
winget install GitHub.GitLFS
# (or install Git for Windows, which bundles Git LFS as an optional component)
# Then (once, per machine)
git lfs install
If you hit git-lfs filter-process: command not found during git clone or npx skills add heygen-com/hyperframes, install Git LFS and retry. You can also skip LFS content if you only need the source files:
GIT_LFS_SKIP_SMUDGE=1 git clone https://github.com/heygen-com/hyperframes.git
