* fix(cli): prefer puppeteer cache + numeric version sort (staff review) Two correctness fixes from PR #821 self-review: 1. Cache priority order. Previous order was hyperframes-managed cache → puppeteer cache. HF cache is pinned to CHROME_VERSION (131-era) which lags 17+ releases behind upstream; if a user separately installed a newer chrome-headless-shell via @puppeteer/browsers install, the CLI would silently hand engine the older HF-cache binary while engine's own resolveHeadlessShellPath would have picked the newer one. Flip the priority so puppeteer cache wins, matching engine semantics. 2. Numeric (not lexicographic) version sort. `readdirSync.sort().reverse()` over names like `linux-148.0.7778.97` and `linux-99.0.6533.123` would return `linux-99...` first because character '9' outranks '1'. Parse each name into integer segments and compare them numerically. Tests: add both-caches-populated and linux-148-beats-linux-99 cases. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * perf(engine): page-side compositing for shader transitions (opt-in spike) Add an opt-in `--page-side-compositing` flag (CLI) backed by a new engine config field `enablePageSideCompositing` and env var `HF_PAGE_SIDE_COMPOSITING`. When set, SDR shader-transition compositions skip the Node-side layered blend (the hf#677 chain) and instead run the shader inside Chrome via a page-side WebGL canvas; the engine then captures ONE opaque RGB frame per output frame via the existing streaming capture path. This is the strongest non-beginFrame perf lever for Mac users, who cannot take the beginFrame `~5×` path (Chromium structural limit, crbug.com/40656275). Stacks on top of the hf#677 1.95× baseline. Default OFF — existing fixture pins (byte-exact MP4 output) are preserved. Opt-in path is intentionally PSNR-pinned, not byte-equal (WebGL is f32; Node is f64). HDR content forces the existing layered path regardless. Implementation: - engine: new `EngineConfig.enablePageSideCompositing` (default false). - producer/fileServer: new `HF_PAGE_SIDE_COMPOSITING_STUB` early-page script injected into the served HTML head when the flag is on. - producer/renderOrchestrator: when the flag + no HDR + no png-sequence, route SDR transitions through the streaming path instead of the layered HDR stage. - shader-transitions: new `engineModePageComposite.ts` installs a fullscreen WebGL compositor overlay and wraps `window.__hf.seek` so each seek inside a transition window captures both scenes via the Chromium `drawElementImage` API to GL textures, runs the fragment shader, and displays the composited result on the overlay canvas. The engine takes one screenshot per frame and sees the composited overlay. - cli: new `--page-side-compositing` flag sets `HF_PAGE_SIDE_COMPOSITING=true` before producer load. - scripts/page-side-compositing-smoke: bundled-CLI smoke that renders a representative fixture with and without the flag, validates the canary strings are in the shipped bundles, and writes a wall-time pair. Determinism trade documented in the engine config doc-comment. The smoke script enforces the bundled-CLI validation discipline from prior perf work (see internal feedback note `validate_bundled_cli_not_dev_path`). Runtime requirement: Chromium's `CanvasDrawElement` feature (already enabled by the engine's `--enable-features=CanvasDrawElement` launch flag). When the runtime feature is unavailable, the page-side installer logs a warning and falls back to opacity-flip mode — the engine still takes the streaming path; the transition window degrades to a hard scene swap. Vance will validate on Mac Chrome where the feature is supported. Co-Authored-By: Vai <vai@heygen.com> * fix(shader-transitions): use html2canvas for page-side compositor capture The original drawElementImage approach fails in engine render mode because the virtual-time shim prevents Chromium from generating paint records for cloned elements. drawElementImage requires a cached paint record from the browser's compositor — clones created at capture time never receive one because (a) shimmed rAFs deadlock inside the seek wrapper, (b) original rAFs don't produce real paints under virtual-time control, and (c) layoutsubtree canvases don't apply CSS stylesheet rules to children. Switch scene capture to html2canvas (foreignObjectRendering: false), the same JS-based renderer already used by the preview-mode fallback path in capture.ts. html2canvas reads computed styles and renders via its own canvas drawing pipeline with no dependency on the browser paint cycle. Also fixes: - Engine seek must return the result so Puppeteer awaits async seek promises (frameCapture.ts). - GSAP opacity cache: compositor must restore scene opacity before seek, not after — GSAP caches inline values and skips re-writes. - Support check gates on WebGL availability, not drawElementImage. Perf: 15-scene shader-perf fixture (28s, 14 transitions, 30fps) Baseline (Node-side layered): 137s Page-side (html2canvas+WebGL): 33s → 4.1× speedup Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * refactor(shader-transitions): simplify review fixes for page-side compositor - Use uploadTexture (zeroes canvas backing store after upload) to prevent ~2.2GB transient memory pressure across 280 html2canvas calls per render - Add ignoreElements + stabilizeTransformedBoxShadows to html2canvas call, matching the preview-path capture.ts behavior - Parallelize from/to scene captures with Promise.all - Wrap post-capture render in try/finally so opacity is always restored - Fix WebGL context leak in isPageSideCompositingSupported probe - Remove dead ResolvedTransition.index field - Export stabilizeTransformedBoxShadows from capture.ts Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(producer): unify page-side compositing gating and Docker forwarding Addresses three issues from staff review: 1. ignoreElements filter stripped all in-scene canvases (Chart.js, D3, p5.js) — narrowed to data-no-capture only since the compositor canvas is a body sibling never in the scene subtree. 2. Docker mode silently dropped --page-side-compositing — thread pageSideCompositing through DockerRenderOptions/buildDockerRunArgs with regression tests. 3. Fragmented gating across 4 independent sites could disagree: - Stub injection gated only on cfg flag (leaked into HDR/alpha) - Probe-created fileServer never got the stub - needsAlpha (WebM/MOV) not excluded from the gate - WebGL-unavailable fallback claimed layered path would run but orchestrator had already disabled it Fix: compute stub injection at the same site as the layered-bypass decision (after hasHdrContent is known), using addPreHeadScript on the already-running fileServer. Single predicate now gates both decisions, including !needsAlpha. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * perf(engine): two-phase drawElementImage capture for page-side compositing Replace html2canvas with native drawElementImage for scene capture in the page-side compositor. drawElementImage reads from the browser's own paint cache, giving pixel-identical output to the preview path. The blocker was that cloned elements inside layoutsubtree canvases have no cached paint record under virtual time — the compositor only paints when explicitly triggered. Fix: split the seek+composite into two phases with an engine-forced paint between them. Phase 1 (seek wrapper, page-side): - GSAP seek positions the timeline - Clone FROM/TO scenes into visible layoutsubtree staging canvases - Set window.__hf_page_composite_pending flag Engine paint force (frameCapture.ts): - Detect pending flag after seek returns - Fire micro Page.captureScreenshot (1x1 clip) via CDP to force the browser compositor to paint all visible elements including staging canvas children Phase 2 (page.evaluate, page-side): - drawElementImage reads the now-valid paint records - Upload textures to WebGL, run shader, show GL overlay Key insight: staging canvases must be visible (not opacity:0) for the browser to paint their children. They sit at z-index:-9998, behind the main DOM and covered by the GL overlay during transitions. Perf: 15-scene fixture (28s, 14 transitions, 30fps): Baseline (Node-side layered): 137s html2canvas + WebGL: 33s (3.7×) drawElementImage + WebGL: 21s (6.6×) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * perf(engine): optimize two-phase compositor hot path - uploadTextureSource instead of uploadTexture: eliminates ~2.3GB of canvas buffer alloc/dealloc churn (persistent staging canvases don't need the one-shot zeroing behavior) - Fold hasPending check into seek page.evaluate: eliminates one CDP round-trip per frame (~700 unnecessary IPC calls on non-transition frames) - Fix renderShader error handling: on failure, leave source scenes visible as fallback instead of hiding both scenes + GL overlay (which produced black frames) - Move mutable state declarations above resolveComposite to prevent TDZ risk on refactor Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(engine): staff review — staging cleanup, pending flag, beginFrame guard - Clear staging canvas children when leaving transition window (prevents visible clone bleed-through on transparent compositions) - Clear __hf_page_composite_pending on all resolveComposite exit paths - Guard micro-screenshot paint force against beginFrame mode (CDP Page.captureScreenshot conflicts with beginFrame compositor control) - Update CLI flag description: document video/canvas limitation, remove stale PSNR claim Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat(engine): default-on page-side compositing for SDR shader transitions Page-side compositing is now enabled by default for SDR shader-transition renders without video content. The 6.6× speedup applies automatically — no flag needed. Auto-disables when: - HDR content detected - Alpha output (WebM/MOV/PNG-sequence) - Composition contains <video> elements (cloneNode loses playback state) - beginFrame capture mode (Linux headless) Use --no-page-side-compositing to force the Node-side layered path. Changes: - Engine config: enablePageSideCompositing defaults to true - CLI: flag default flipped to true; --no-page-side-compositing disables - Orchestrator: added composition.videos.length === 0 gate - Docker: forwards --no-page-side-compositing when explicitly disabled - Config tests updated for new default Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat(engine): support video elements on page-side compositing fast path Three-phase capture protocol lets shader transitions render video scenes without falling back to the slow Node-side layered pipeline: 1. Seek → compositor records transition metadata, sets pending flag 2. onBeforeCapture → video frame injector updates <img> replacements 3. prepare → cloneNode picks up current video frames, img.decode() awaits 4. micro-screenshot → forces browser to paint cloned elements 5. resolve → drawElementImage reads paint records, shader composites Key changes: - Remove `composition.videos.length === 0` gate from orchestrator - Split compositor resolve into prepare (clone) + resolve (shader) - Move onBeforeCapture before compositor prepare in frameCapture.ts - Await img.decode() on cloned data-URI images to prevent stale frames - Stop manipulating scene opacity in compositor (GL canvas overlay suffices) - Add gsap.set declaration for shader-transitions ambient types - Add video_missing_timing_attrs lint rule for <video> without id/data-start/data-end Performance: compositions with video now render at 7.5s (6 workers) instead of 2m38s on the layered path. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(core): auto-inject data-start on video/audio so frame extraction works without explicit attrs The timing compiler now injects data-start="0" on <video> and <audio> elements that lack it. This makes discoverMediaFromBrowser() find the element (it queries video[data-start]), so the frame extraction pipeline activates automatically. Videos "just work" without requiring authors to add data-start, data-end, or id attributes. Also removes the video_missing_timing_attrs lint rule — the compiler handles the missing attributes automatically, so the lint rule would only false-positive. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat(core): add data-hf-auto-start sentinel on auto-injected video timing Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat(producer): add discoverVideoVisibilityFromTimeline for runtime video discovery Seeks the GSAP timeline in Puppeteer to discover when each video's parent scene is visible (opacity > 0). Uses coarse sampling at 100ms steps followed by binary search refinement to frame-level precision (1/60s). Only processes videos with the data-hf-auto-start sentinel so author-specified timing is never overridden. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * feat(producer): integrate runtime video visibility discovery into probe stage Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(producer): trigger browser probe for auto-start videos, remove debug logging The probe stage was skipping browser launch when composition duration was already known, which meant discoverVideoVisibilityFromTimeline never ran. Now needsBrowser also checks for data-hf-auto-start sentinel in compiled HTML. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix(scripts): use mkdtempSync for smoke test work directory Replaces hardcoded /tmp/hf-page-side-smoke with a unique temp directory via mkdtempSync to resolve CodeQL "insecure temporary file" alert. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * style: format smoke test script Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com> Co-authored-by: Vai <vai@heygen.com>
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 the dev-loop commands (init, lint, preview, render), /hyperframes-media for asset preprocessing (TTS, transcription, background removal), /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 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 |
Dev-loop CLI: init, lint, inspect, preview, render, doctor |
hyperframes-media |
Asset preprocessing: tts (Kokoro), transcribe (Whisper), remove-background (u2net) — voice/model/codec selection |
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
