Miguel Ángel
267ffd3fca
## Problem Template-wrapped sub-compositions could still lose correct parent timing during render in more than one place. In the validated repros, a host sub-composition starting after the intro (and in one follow-up repro, starting at `20s` after earlier compositions) contained scene-local media inside it. On the broken paths: - template-wrapped media could be missed during compile and scheduled at raw scene-local time - already-correct first-pass offsets could be clobbered during `recompileWithResolutions()` - even after those two fixes, the browser-metadata reconcile step in `executeRenderJob()` could still overwrite a compiled global `end` with a scene-local `data-end` from the inlined DOM, clipping the tail off late-start sub-composition media ## What this fixes ### Template-wrapped media discovery - `parseVideoElements`, `parseImageElements`, and `parseAudioElements` now unwrap a single top-level `<template>` wrapper before scraping media - the unwrap helper is DOM-based, not regex-based, so it avoids the CodeQL backtracking warning and only unwraps the exact single-wrapper shape we want - multiple sibling templates or other top-level content are left untouched instead of being rewritten heuristically ### Offset preservation after duration resolution - `recompileWithResolutions()` now preserves the first-pass sub-composition media arrays when the already-inlined HTML no longer contains `[data-composition-src]` hosts - that prevents correctly offset media metadata from being overwritten by scene-local media parsed from the merged DOM ### Browser metadata reconciliation in the compiled time origin - browser-discovered media can still report scene-local `data-start` / `data-end` from the merged DOM after inlining - the producer now reprojects browser `end` values into the compiled element's time origin before reconciling them back into `composition.videos` / `composition.audios` - this prevents late-start sub-composition media from getting truncated back to a scene-local end during the probe phase ### Regression coverage - adds focused engine tests for the template unwrap helper - adds producer regression coverage for both the initial compile path and the post-inline `recompileWithResolutions()` path - adds producer regression coverage for late-start host compositions (`t≈20`) with scene-local media inside them - adds producer unit coverage for the browser-end reprojection helper used by the reconcile path ## Root cause There were three distinct renderer failures behind the bug: ### 1. Template contents were invisible to the media scrapers `parseSubCompositions()` reads raw sub-composition HTML and applies the host offset to discovered media. But the engine media helpers were querying the parsed document directly, and linkedom follows browser semantics here: top-level `<template>` contents live in a `DocumentFragment`, so `querySelectorAll()` never saw those `<video>` / `<audio>` / `<img>` nodes. That meant template-wrapped sub-compositions could silently produce zero discovered media during the first pass. ### 2. The duration-resolution recompile could clobber already-correct offsets After the browser resolves composition durations, `recompileWithResolutions()` reparses the already-inlined HTML. By that point the original `[data-composition-src]` hosts are gone, so `parseSubCompositions()` legitimately returns no nested media. The old code still rebuilt the deduped media arrays from the merged DOM, which let scene-local media parsed from the inlined HTML overwrite the correctly offset first-pass metadata. ### 3. The browser probe reconcile path mixed two timing coordinate systems `discoverMediaFromBrowser()` reads `data-start` / `data-end` directly from the live DOM after sub-compositions are already inlined. For nested media, those attributes can still be scene-local even though the compiled metadata has already been offset into the parent host timeline. The old reconcile path compared those values directly and overwrote `existing.end` whenever the numbers differed. For a late-start sub-composition, that could replace a correct global end like `25.5` with a scene-local end like `5.5`, cutting the clip off during render. ## Verification ### Local checks - `bun test packages/engine/src/utils/htmlTemplate.test.ts` - `bun test packages/producer/src/services/htmlCompiler.test.ts` - `bunx vitest run packages/producer/src/services/renderOrchestrator.test.ts` - `bun run --filter @hyperframes/engine test` - `bun run --filter @hyperframes/engine typecheck` - `bun run --filter @hyperframes/producer typecheck` - `bunx oxlint packages/engine/src/utils/htmlTemplate.ts packages/engine/src/utils/htmlTemplate.test.ts packages/producer/src/services/renderOrchestrator.ts packages/producer/src/services/renderOrchestrator.test.ts packages/producer/src/services/htmlCompiler.test.ts` - `bunx oxfmt --check packages/engine/src/utils/htmlTemplate.ts packages/engine/src/utils/htmlTemplate.test.ts` - `bun run build:producer` ### Render / browser verification Verified against two local repros: 1. **Early offset repro** - host starts at `2s` - child media is scene-local `0-4s` - compiled render summary keeps the child video/audio at `start: 2` - browser verification via `agent-browser` confirmed the `2.2s` frame still shows the child clip active in the host timeline 2. **Late offset repro** - earlier compositions run first, then the target host starts at `20s` - child media starts scene-local at `1.5s` and should remain visible through `24.5s` - compiled render summary keeps the child video/audio at `start: 21.5`, `end: 25.5` - browser verification via `agent-browser` confirmed the `24.5s` frame still shows the late clip visible, which is the exact tail-clipping case the old reconcile path could break ## Notes - the `/tmp/hf-pr475-repro` and `/tmp/hf-pr476-late-offset-repro` projects plus their browser-proof artifacts are verification-only and are not part of this PR - this PR stays narrowly scoped to sub-composition media timing across compile, recompile, and browser probe reconciliation; it does not broaden into general sub-composition HTML normalization beyond the single-wrapper case
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 and GSAP animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for CLI commands, and /gsap for animation help.
For Claude Design, open skills/claude-design-hyperframes/SKILL.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 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 |
|---|---|
claude-design-hyperframes |
Template-first Claude Design skill — pre-valid skeletons, produces video drafts for refinement in any coding agent |
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 |
gsap |
GSAP animation API, timelines, easing, ScrollTrigger, plugins, React/Vue/Svelte, performance |
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