* feat(core): route grouped audio through a group bus in preview An audio element carrying `data-audio-group` no longer lands its gain on the master bus directly — it feeds a per-group `GainNode` (built lazily on first use, one per group id) which itself feeds master, so members of the same group sum before the ear, ready for a group-level FX chain and volume/mute in later steps. An id with no matching `<hf-audio-group>` element still gets a plain, unprocessed bus rather than losing the track. The group's own chain and volume lane are wired through the same `attachElementFxChain`/`scheduleVolumeLane` every element already uses, against the group's clock — composition time (design doc §1.3), since a group has no `data-start` and a missing one parses as 0. The bus persists across `stopAll()` (mirroring `_masterGain`'s own lifecycle) so replaying a group does not rebuild its chain; only `destroy()` disposes it. Render is untouched — stays flat until B4; `audio-groups` is still a 0% canary so nothing ships this to a real composition without hand-authoring `data-audio-group`. Also: `audioGroupOf` (B1) crashed on any element lacking a real `tagName`/ `getAttribute` — exactly the shape of most `HTMLMediaElement` test doubles in this suite, including this file's own `mockEl`. Made it tolerant, same style as `readChain`'s existing guard in `runtime/audioFx.ts`. `schedulePlayback` was already 110 lines pre-existing before this diff; extracted `resolveDestination` and `handleSourceEnded` to shrink it to 92, then suppressed the remainder (inherently sequential graph wiring, not a decision tree) per the same precedent B2 used on `TimelineLogicalRow`. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> * feat(studio,lint): carve targets voiceover groups — always, when plural Plural voiceover carve now targets a group instead of naming each clip: `resolveCarveSourceIds` (core `audioGroups.ts`) expands a group id to its current members at analysis time, so a clip added to the group later is covered without touching `sources`. The picker (`useFxCarve.ts`) offers a grouped voice as one option instead of one row per member, tests overlap as a union of member spans (a group overlaps the bed if ANY member does), and prefers a qualifying group over its individual members in `autoSourceIds`. Picking two or more ungrouped voice clips in the carve flow now mints a group behind them (`mintGroupId`, de-duped against every id in the document) and writes `data-audio-group` on each picked clip atomically, one undo entry — `createAudioGroupAndAssignMembers` in `timelineTrackVisibility.ts` copies `setElementsHidden`'s multi-target write shape. The DSP is untouched: `mixCarveSources` already sums multiple sources correctly (verified in the design doc's own investigation) — this only fixes the picker. New lint rule `audio_carve_ungrouped_sources` (`packages/lint/src/rules/ media.ts`, alongside `audio_volume_double_automation`) warns when a `data-fx-carve`'s `sources` names two or more plain clip ids instead of a group — the shape that silently rots when a clip is added. `/hyperframes- audio` states the same rule as an invariant, not a tip, with the grouped- narration HTML example from the design doc. The group-matching and auto-group logic (`withAutoGroupedSources`, `collectCarveCandidates`) is split into `useFxCarveGrouping.ts` — `useFxCarve.ts` was pushing past the 600-line cap. `resolveNextCarveSettings` is deliberately NOT an `async function`: wrapping it in one would force a microtask on every call, including the synchronous branch — the exact bug `withAutoGroupedSources`'s own sync-when-possible contract exists to avoid, and one caught via `propertyPanelAudioFxGroup.test.tsx` (10 failures) before fixing it back to a plain function the caller conditionally awaits. Also extracted `useEffectiveTimelineDuration` out of `App.tsx` and `useRemoveBackground` out of `StudioRightPanel.tsx` (both pushed past 600 lines from an added prop wire), and decomposed `useFxCarve.ts`'s picker IIFE to clear fallow's complexity gate. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> * feat(engine): render grouped audio through a summed, FX-processed bus Renders what B3 already routes in preview: a group's members sub-mix into one PCM WAV at full composition length (adelay already places each member at its composition position, so the group WAV's t=0 IS composition time), run through the group's own FX chain and automation via the same applyAudioFxChain/envelope-bake path a member uses, then fold into the flat track list as one processed AudioTrack — the final mixAudioTracks call never has to know groups exist. Gain law verified against plans/spikes/amix-nesting-spike.sh (brought over from the plans branch, along with audioMixer.grouping.test.ts, since both were committed there and never merged to origin/main — every step branch in this stack descends from origin/main): the sub-mix's own amix prefers normalize=0 (nulls exactly against a flat mix), falling back to per-node compensation by the group's OWN member count only when this ffmpeg build's amix rejects the option. Carrying any other count into a nested amix node is the exact +2.499 dB silent failure the spike measured — confirmed by a manual mutation check (wrong-count compensation landed 3.5 dB hot, exactly 20*log10(3/2) for a 2-member group compensated as 3; reverted after confirming the level test catches it). A group element carrying data-hidden drops every member before the sub-mix ever runs (RULES: mute-by-drop, never mute-by-volume-0) — parseAudioElements now resolves groups once per parse and skips hidden-group members the same way it already skips data-hidden ancestors. HfAudioGroup (packages/core/src/audioGroups.ts, from B1) gains fxChain, automation, volume and hidden, read off the group element the same way resolveAudioGroups already reads data-label — audioGroups.test.ts updated for the wider shape plus new coverage for the added reads. it.todo("mixes a grouped composition at the same level as the ungrouped one") is now a real, passing test; two more added per the step doc (FX routing isolation, member-level envelope survives grouping). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> --------- Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
Write HTML. Render video. Built for agents.
Quickstart | Showcase | Playground | Catalog | Docs | Discord
HyperFrames is an open-source framework for turning HTML, CSS, media, and seekable animations into deterministic MP4 videos. Use it locally with the CLI, from AI coding agents with skills, or as the rendering core behind hosted authoring workflows.
Quick Start
With an AI coding agent
Install the HyperFrames skills, then describe the video you want:
npx skills add heygen-com/hyperframes --full-depth
The picker opens with nothing pre-selected — the Core Skills group is all you need: the
/hyperframesrouter installs each creation workflow on demand. Agents and non-interactive runs should usenpx hyperframes skills updateinstead — it installs exactly the core set, whereas a non-interactiveskills addwithout--skillinstalls all 20.
--full-depthdoes a full clone of the repo's currentmain. Without it,skills addfetches the skills.sh registry blob, which lagsmainby hours — you'd get an older copy of a skill. (hyperframes skills updatealready installs full-depth.)
Try a prompt like:
Using
/hyperframes, create a 10-second product intro with a fade-in title, a background video, and subtle background music.
The skills teach agents the HyperFrames production loop: plan the video, write valid HTML, wire seekable animations, add media, lint, preview, and render. They work with Claude Code, Cursor, Gemini CLI, Codex, and other coding agents that support skills.
Skills
HyperFrames ships 20 skills agents load on demand. Read /hyperframes first — it's the router and capability map; it picks a workflow for any "make me a…" request — video, deck, or composition port — and points to the domain skills below.
Default to the core set — the router installs each creation workflow on demand. npx hyperframes skills update installs exactly that from anywhere; the interactive picker (npx skills add heygen-com/hyperframes --full-depth) lists it as the "Core Skills" group, nothing pre-selected. The picker is interactive-only — a non-interactive or agent run without --skill installs all 20. Use npx skills add heygen-com/hyperframes --all --full-depth to install all 20 deliberately (skips the picker), or npx skills add heygen-com/hyperframes --skill <name> --full-depth for just one (bare name, no leading /). Keep --full-depth — it installs the current main; without it skills add fetches the skills.sh blob, which lags by hours.
Installs stay lean after that: npx hyperframes init keeps the core set fresh (the router, the hyperframes-* domain skills, and media-use — plus whatever is already installed; /figma stays on demand) and never expands a partial install; the creation workflows install on demand — the router runs npx hyperframes skills update <workflow> before entering one. Nothing re-pulls the full set behind your back.
Upload to Codex
Build the upload-ready Codex plugin archive from the committed HEAD version of the manifest, brand assets, and skills:
bun run package:codex-plugin
This writes dist/hyperframes-plugin.zip with a hyperframes/ root folder and fails if the archive exceeds Codex's 100 MB upload limit.
Router
| Skill | Use when |
|---|---|
/hyperframes |
Read first for any request to make / create / edit / animate / render a video, animation, or motion graphic. Capability map for the domain skills, the intent layer that confirms every creation brief up front, and intent router for the creation workflows below. |
Creation workflows
| Skill | Use when |
|---|---|
/product-launch-video |
Any website — marketing / launching / promoting a product (from its URL, a brief, or a script), or a site tour / showcase / social clip featuring the site's own visuals. Up to ~3 min (sweet spot 30-90s). |
/faceless-explainer |
Explaining a topic / concept from arbitrary text — no product, no URL, no website capture; every visual is LLM-invented (typography / abstract / diagram / data-viz). |
/pr-to-video |
A GitHub pull request (PR URL, owner/repo#N ref, or "this PR") → changelog / feature-reveal / fix / refactor explainer, read via the gh CLI. |
/embedded-captions |
Adding captions / subtitles to an existing talking-head video (footage untouched) — verbatim rail, embedded climax behind the subject, or pure-cinematic embed. |
/talking-head-recut |
Packaging an existing talking-head / interview / podcast video with designed graphic overlays — lower-thirds, data callouts, kinetic titles, pull-quotes, side panels, PiP. |
/motion-graphics |
A short, unnarrated, design-led motion graphic (~under 10s) — kinetic type, stat / chart hit, logo sting, lower-third, animated tweet / headline. MP4 or transparent overlay. |
/music-to-video |
A music track (audio file, video to pull audio from, or one generated from a mood brief) → a beat-synced video — lyric, slideshow, or kinetic promo; music drives pacing. |
/slideshow |
A presentation / pitch deck / interactive deck — discrete slides, fragment reveals, branching, hotspot navigation, presenter mode. Output is a navigable deck, not a rendered video. |
/general-video |
Anything else — longer or multi-scene pieces, brand / sizzle reel, title card, static loop, freeform composition. Input- and length-agnostic fallback, and the home of companion mode (co-create with the full toolbox). |
/remotion-to-hyperframes |
Porting an existing Remotion (React) composition's source to HyperFrames HTML. One-way migration, not creation. |
Domain skills (loaded on demand)
Atomic capabilities the creation workflows compose against — pull one when you need that specific layer.
| Skill | Covers |
|---|---|
/hyperframes-core |
The composition contract — data-* timing attributes, class="clip", tracks, sub-compositions, variables, framework-owned media playback, determinism rules. |
/hyperframes-animation |
All animation knowledge — atomic motion rules, scene blueprints, transitions, runtime adapters (GSAP / Lottie / Three.js / Anime.js / CSS / WAAPI / TypeGPU). |
/hyperframes-keyframes |
Seek-safe keyframe authoring across runtimes — GSAP timelines, CSS keyframes, Anime.js, WAAPI, FLIP, paths, masks, SVG morph/draw, 3D depth — plus hyperframes keyframes diagnostics for rendered motion. |
/hyperframes-creative |
Non-animation creative direction — frame.md / design.md, palettes, typography, narration, beat planning, audio-reactive visuals, composition patterns. |
/media-use |
The media OS — resolve any media need (BGM, SFX, image, icon, logo, voice, color grade, LUT) into a frozen local file or paste-ready block + ledger record, generate via TTS/music/image models when the catalog misses, transcribe, caption, remove backgrounds, and reuse assets across projects. One shared audio engine + manifest tracking. |
/hyperframes-cli |
CLI dev loop — init, lint, check, snapshot, preview, render, publish, doctor, plus HeyGen-hosted cloud rendering (cloud render) and AWS Lambda rendering (lambda deploy / render / progress). |
/hyperframes-audio |
Mix the audio already placed in a composition — voiceover carve (dip a music bed only in the bands the voice occupies, static or dynamic, level match included), the effect chain (EQ, compressor, limiter, gate, saturation, delay, reverb, chorus, phaser, bitcrush), and automation envelopes on volume or any effect parameter. Sourcing the audio is /media-use. |
/hyperframes-registry |
Install and wire registry blocks and components into compositions via hyperframes add. Authoring a new block or component to contribute upstream. |
/figma |
Import Figma assets, tokens, components, and storyboard sections → reconstructed motion (frames read as states, not slides) (REST/CLI) plus Motion animations (MCP) and shaders (MCP source / native export) into a composition. |
For visual design handoff workflows, see the Claude Design guide and Open Design guide.
Manually with the CLI
npx hyperframes init my-video
cd my-video
npx hyperframes preview # preview in browser with live reload
npx hyperframes render # render to MP4
Requirements: Node.js 22+, FFmpeg
What You Can Build
Need ideas? Browse the Showcase for finished videos you can watch, read, run, and remix.
- Product launch videos and feature announcements
- PR walkthroughs with animated code diffs, narration, and captions
- Data visualizations, chart races, and map animations
- Social videos with kinetic captions, overlays, and music
- Docs-to-video, PDF-to-video, and site-tour explainers
- Reusable motion graphics for automated content pipelines
Frame.md
frame.md — your design system, ready for video.
Every brand has a design.md. None of them were written for a camera. frame.md is the missing translation layer: it takes your web-context design spec and inverts it for the frame — the same tokens, the same rules, but rewritten so an AI agent can compose a promo video without guessing at scale or reaching for web chrome.
The output is a DESIGN.md superset your whole toolchain can read. Atoms stay sacred. Composition stays free. Numbers come from the script.
Biennale Yellow |
BlockFrame |
Blue Professional |
Bold Poster |
Broadside |
Capsule |
Cartesian |
Cobalt Grid |
Coral |
Creative Mode |
Browse and remix them all at hyperframes.dev/design.
How It Works
Define a video as HTML. Add data attributes for timing and tracks. Use GSAP, CSS, Lottie, Three.js, Anime.js, WAAPI, or your own frame adapter for seekable animation.
<div id="stage" data-composition-id="launch" data-start="0" data-width="1920" data-height="1080">
<video
class="clip"
data-start="0"
data-duration="6"
data-track-index="0"
src="intro.mp4"
muted
playsinline
></video>
<h1 id="title" class="clip" data-start="1" data-duration="4" data-track-index="1">Launch day</h1>
<audio
data-start="0"
data-duration="6"
data-track-index="2"
data-volume="0.5"
src="music.wav"
></audio>
<script src="https://cdn.jsdelivr.net/npm/gsap@3/dist/gsap.min.js"></script>
<script>
const tl = gsap.timeline({ paused: true });
tl.from("#title", { opacity: 0, y: 40, duration: 0.8 }, 1);
window.__timelines = window.__timelines || {};
window.__timelines.launch = tl;
</script>
</div>
Preview instantly in the browser. Render locally or in Docker. The renderer seeks each frame in headless Chrome and encodes the result with FFmpeg, so the same input produces the same video.
HyperFrames Stack
HyperFrames is the open-source rendering engine, plus a growing set of tools around HTML-native video creation.
| Piece | Status | What it does |
|---|---|---|
| CLI | Available | Scaffold, preview, lint, inspect, and render local video projects |
| Core / Engine / Producer | Available | Parse compositions, drive headless Chrome, encode video, and mix audio |
| Catalog | Available | Reusable blocks and components for transitions, overlays, captions, charts, maps, and effects |
| Agent skills | Available | Teach coding agents the video-production patterns that generic web docs miss |
| Studio | Available, evolving | Browser surface for previewing and editing compositions |
| AWS Lambda rendering | Available | Deploy a distributed render stack and drive renders from your laptop or CI |
| hyperframes.dev | Available | Community playground for previewing, iterating, sharing, and rendering HTML-native video projects |
| frame.md | Available | Invert your design system for the camera — a DESIGN.md superset an agent can compose video from |
Catalog
Install ready-to-use blocks and components:
npx hyperframes add flash-through-white # shader transition
npx hyperframes add instagram-follow # social overlay
npx hyperframes add data-chart # animated chart
Browse the catalog at hyperframes.heygen.com/catalog.
Why HyperFrames?
- HTML-native: compositions are HTML files with data attributes. No React requirement, no proprietary timeline format.
- Agent-friendly: agents already write HTML, and the CLI is non-interactive by default.
- Deterministic: same input, same frames, same output. Built for CI, regression tests, and automated rendering.
- No build step: an
index.htmlcomposition plays as-is and can be previewed directly in the browser. - Adapter-based animation: bring GSAP, CSS animations, Lottie, Three.js, Anime.js, WAAPI, or a custom runtime.
- Open source: Apache 2.0 license, with no per-render fees or commercial-use thresholds.
HyperFrames vs Remotion
HyperFrames is inspired by Remotion. Both tools render video with headless Chrome and FFmpeg. The main difference is the authoring model: Remotion's bet is React components; HyperFrames' bet is plain HTML that humans and agents can both write easily.
| HyperFrames | Remotion | |
|---|---|---|
| Authoring | HTML + CSS + seekable animation | React components |
| Build step | None; index.html plays as-is |
Bundler required |
| Agent handoff | Plain HTML files | JSX / React project |
| Library-clock animations | Seekable, frame-accurate via adapters | Wall-clock animation patterns need care |
| Distributed rendering | Local and AWS Lambda render paths | Remotion Lambda, mature cloud renderer |
| License | Apache 2.0 | Source-available Remotion License |
Read the full comparison in the HyperFrames vs Remotion guide.
Documentation
Full documentation: hyperframes.heygen.com/introduction
Packages
| Package | Description |
|---|---|
hyperframes |
CLI for creating, previewing, linting, and rendering compositions |
@hyperframes/core |
Types, parsers, generators, linter, runtime, and frame adapters |
@hyperframes/engine |
Seekable page-to-video capture engine using Puppeteer and FFmpeg |
@hyperframes/producer |
Full rendering pipeline for capture, encode, and audio mix |
@hyperframes/studio |
Browser-based composition editor UI |
@hyperframes/player |
Embeddable <hyperframes-player> web component |
@hyperframes/shader-transitions |
WebGL shader transitions for compositions |
@hyperframes/aws-lambda |
AWS Lambda SDK and deployment surface for distributed renders |
Community
HyperFrames is used in production at HeyGen, with community examples from teams like tldraw, TanStack, and others in ADOPTERS.md. Open a PR if your team is using HyperFrames.
- Questions and ideas: Discord
- Bugs and feature requests: GitHub Issues
- User research: Book a casual 30-minute conversation with the HyperFrames team — no preparation or sales pitch
- Security reports: SECURITY.md
- Contributions: CONTRIBUTING.md
Development Note
The repo uses Git LFS for golden regression-test baselines under packages/producer/tests/**/output.mp4 (about 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
# Then, once per machine
git lfs install
If you only need source files, you can skip LFS content:
GIT_LFS_SKIP_SMUDGE=1 git clone https://github.com/heygen-com/hyperframes.git










