miga-heygenandMiguel Ángel
9460c983e0
* fix(engine): recover audio duration from packet timestamps before clamping An authored `data-duration` on an <audio> element could be silently shortened when a source file's container-summary duration (mvhd/tkhd/mdhd) undercounts the real audio length while the packet stream itself is intact. Add `probeAudioDurationFromPackets()`, which re-derives the true duration from the last packet's own pts_time + duration_time — figures ffprobe computes from the stream's own timestamps, not the container's summary header — and wire it into the compiler's existing clamp check as a rescue attempt before accepting a shorter value. Works regardless of codec/profile; verified against real HE-AAC/SBR fixtures and a binary-patched "lying container" MP4 built for the regression test. The rescue only fires for candidates the existing clamp predicate already flagged (no added cost on the common path), runs in parallel across candidates rather than serially, and requires the recovered duration to exceed the existing clamp epsilon (absorbing the few milliseconds of priming-delay drift raw packet timestamps carry relative to an edit-list-corrected container duration) before overriding the shorter value. Co-Authored-By: Miguel Ángel <miguel.sierra@heygen.com> * fix(engine): move audio duration correction into extractAudioMetadata The previous approach compared the compiler's own packet-scan probe against the already-corrected duration returned by extractAudioMetadata, which meant the correction only applied to one caller and the regression fixture happened to exercise a pre-existing AAC-LC-specific refinement instead of the new code path. Move the fix to the single canonical place duration is derived: replace the old AAC-LC-only packet-count refinement (a profile allowlist assuming a fixed 1024-samples-per-frame constant) with a codec-agnostic mechanism that decodes the final audio frame and reads its own timestamp plus real sample count. This has no per-codec assumption, so it applies uniformly regardless of codec or profile, and every caller of extractAudioMetadata benefits automatically. The compiler's own clamp logic is now unchanged from its pre-existing form. Verified against a real, previously-untouched case: a FLAC-in-MP4 file (a codec the old AAC-LC-only path never corrected) with its mvhd/tkhd/mdhd duration atoms binary-patched to half their true value while every real frame stays intact. Confirmed this reproduces on the prior code (by literally substituting its actual content) and is fixed by the new code. The decode probe reads CSV output (each line stands alone) rather than JSON (a single top-level array), and retains only the output tail under a small cap — a lying container's true duration can be arbitrarily larger than its declared one, and JSON truncated from the front isn't valid JSON, so an unbounded scan of a long file silently fell back to the wrong duration once ffprobe's stdout cap was hit. Co-Authored-By: Miguel Ángel <miguel.sierra@heygen.com> * test(producer): update style-7-prod golden for corrected AAC duration probe The deleted AAC-LC packet-count refinement assumed every demuxed packet decodes to exactly 1024 samples. For this suite's real audio fixture (a 48kHz stereo AAC-LC MP4), that assumption overcounts: ffprobe reports 753 demuxed packets, but only 752 of them actually decode into a real audio frame (verified via raw PCM sample count: 770048 samples / 48000Hz = 16.0426666...s). The old mechanism's 753 * 1024 / 48000 = 16.064s was therefore wrong; the new decode-based probe correctly derives ~16.043s from the real final frame. Regression-shards caught this as a compilation mismatch on the previous commit. Verified the corrected golden against the real source: full compilation, visual (0 failed frames), and audio (correlation 0.966) checks all pass locally with the actual LFS-hosted golden video, and a standalone compileForRender() check confirms all other audio-bearing fixture suites in the repo are unaffected. Co-Authored-By: Miguel Ángel <miguel.sierra@heygen.com> * perf(engine): seek the audio decode probe instead of scanning the whole file probeDecodedAudioDuration ran a full, single-threaded decode of the entire audio stream on every extractAudioMetadata call (once per audio element in the HTML compiler, plus audio mixing/padding/encoding steps). On real 30-minute files this took over a second, and could approach ffprobe's 30s deadline on multi-hour files while holding a shared probe slot the whole time. Add -read_intervals so the probe seeks to ~1 second before the container's already-known claimed duration and decodes only that tail. This is safe because the correction only ever raises the duration: an honest or over-claiming container's seek lands at or past the real end and finds nothing extra, while an under-claiming container (the only case this exists to fix) still has real frames past the seek point. If the tail read finds nothing at all, fall back to a full unseeked decode before giving up, protecting files whose seek index is unreliable (an index-less or non-seekably-sourced container) from silently missing a real correction — mirroring the existing seek-then-fallback pattern already used by the sibling final-video-frame probe in this file. Also replaces the real-file regression test's runtime ffmpeg-spawning fixture generation with two small, committed binary fixtures (an honest FLAC-in-MP4 file and a copy with its container duration atoms halved) plus the ffprobe-static package, so this test's real-file proof actually runs in CI instead of being silently skipped when no system ffmpeg is on PATH. Co-Authored-By: Miguel Ángel <miguel.sierra@heygen.com> * refactor(engine): trim the audio duration probe comments to the invariant * test(engine): cache tests queue the decode probe and count metadata probes only * test(engine): probe for ffprobe with a literal argv so the argv contract classifies it * test(producer): regenerate the speed-ramp golden for the single-encode mix The audio probe now reads the mixed AAC as exactly 4.000 s instead of the packet-count 4.032 s (which counted the priming frame), so the final mix is stream-copied instead of re-encoded once more. Same waveform (sample correlation 0.9996 vs the old golden), 3.1 dB less true-peak attenuation; video frames are byte-identical. * fix(engine): measure decoded audio from the stream start and trust it for raw ADTS The decoded last-frame end is an absolute timestamp, so subtract the audio stream's start time (format start as fallback) before comparing it with the start-relative container duration, and start the tail read at start + duration - 1 s. MPEG-TS audio (1.4 s default start) and offset MP4s were over-extended by their start time. Raw ADTS (format aac) has no duration field; ffprobe estimates it from the opening bitrate and overclaims after a quiet opening. Its decoded timestamps are sample-counted, so for raw ADTS the decoded end now wins in both directions beyond the margin. Other containers stay upward-only so an MP4 edit list is never extended. --------- Co-authored-by: Miguel Ángel <miguel.sierra@heygen.com>
Write HTML. Render video. Built for agents.
Studio | 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
For Claude Code, install the versioned plugin:
claude plugin marketplace add heygen-com/hyperframes
claude plugin install hyperframes@hyperframes
Enable auto-update for the hyperframes marketplace in /plugin → Marketplaces,
then use /hyperframes:hyperframes. See the plugin guide
for Copilot, VS Code, Cursor, Gemini CLI, updates, and migration.
For standalone skills (including OpenCode), use:
npx skills add heygen-com/hyperframes
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, whereasskills add --allinstalls all 21 published skills. The six repo-internal skills under.claude/skills/.agents/skillsare excluded by default. For the full published set usenpx hyperframes skills.
skills addresolves the skills.sh registry blob, which can lagmainby hours.npx hyperframes skills updateinstalls from the currentmain, so reach for it when you need the newest copy of a skill.
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, Codex, Cursor, Gemini CLI, IBM Bob, and other coding agents that support skills.
Skills
HyperFrames ships 21 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.
For standalone installation, 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) 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 21. Use npx skills add heygen-com/hyperframes --all to install the complete published set deliberately (skips the picker), or npx skills add heygen-com/hyperframes --skill <name> for just one (bare name, no leading /).
Standalone 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.
Plugin packages
Plugins bundle the full skill catalog and use their agent's update manager.
bun run package:agent-plugin builds the committed portable ZIP, source metadata,
and SHA-256 checksum. See the maintainer checklist.
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 (a host app's own music and sound-effect tools come first for those) — 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), automation envelopes on volume or any effect parameter, and submix buses (<hf-audio-group>) carrying one chain, fader and automation clock for several tracks at once. Sourcing the audio is /media-use. |
/hyperframes-registry |
Search, install and wire registry blocks and components into compositions via hyperframes catalog / hyperframes add. Load before hand-building any named look, effect, treatment or transition. 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