* feat(engine): add packageHls for HLS VOD packaging Adds `packageHls` next to `muxVideoWithAudio`: stream-copies an already-encoded H.264 video and optional AAC sidecar into an HLS VOD directory (`master.m3u8` + split video/audio renditions, MPEG-TS segments) with `-c copy`, so no re-encode happens at package time. Depends on the locked GOP from the previous commit. `-hls_time` can only cut at existing keyframes, so `gopSize = segmentSeconds x fps` is what makes every segment exactly `segmentSeconds` long and IDR-aligned. A test packages an unlocked encode to pin that: the same call yields one 4s segment instead of four 1s ones. Deliberately omits the mp4 mux's provenance tags, which MPEG-TS drops and whose `-movflags` is invalid for `-f hls`, and `-avoid_negative_ts`, which would discard the AAC priming and shift audio against video (see issue 3487). A real-ffmpeg test asserts the first presentable audio sample lands on the first video frame. No caller yet; `format: "hls"` in the producer follows. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> * fix(engine): zero HLS mux base and reject % in packageHls outputDir - Pass -muxdelay 0 -muxpreload 0 so the first segment starts at PTS 0 instead of the mpegts muxer's 1.4 s base; A/V alignment through the AAC priming packet is unchanged - Throw on an outputDir containing %, which ffmpeg expands as a printf conversion in -hls_segment_filename and fails with a misleading "No such file or directory" - Assert alignment on relative spacing rather than on how one ffmpeg build clamps the priming packet's negative PTS - Encode the test fixture with the full software GOP lock (lockedGopCodecParams), not just appendLockedGopArgs - Trim comments to the non-obvious rationale Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * test(engine): satisfy the ffprobe argv contract in packageHls test `producer/src/utils/ffprobeArgvContract.test.ts` sweeps every package at the source level and requires `--` to be the argv entry immediately before an ffprobe input path. The `probe()` helper here passed `join(outputDir, HLS_VIDEO_PLAYLIST)` in that slot, which the contract's comma-splitting parser reads as two entries, so the producer suite was red on this branch while the engine suite stayed green. `probe()` now takes the input path as a parameter and appends the terminator itself. The sibling ffmpeg `run()` helper switches from a spread-in-array-literal to `.concat`, because a verbosity-flag-then-spread literal is indistinguishable from the ffprobe wrapper shape the contract demands a terminator on. The matcher reads raw source including comments. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(engine): drop the audio-only variant from the HLS master playlist With `a:0,agroup:aud` in `-var_stream_map`, ffmpeg lists the audio rendition twice in `master.m3u8`: as the `#EXT-X-MEDIA:TYPE=AUDIO` group the video variant references, and again as a standalone `#EXT-X-STREAM-INF` variant with no `RESOLUTION`. That is valid HLS, but a player choosing by bandwidth can select it and play sound with no picture, and the VOD consumer asked for a single rendition. `stripAudioOnlyVariants` removes any variant tag without a `RESOLUTION` attribute together with its URI line; `packageHls` applies it to the master after a successful audio+video run. The rendition group and the audio playlist are untouched, so `audio.m3u8` is still referenced from the master. Pinned by a unit test on the playlist text and by the real-ffmpeg test, which now asserts exactly one `#EXT-X-STREAM-INF`. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * refactor(producer): extract hdrMode warning and decision-log helpers `resolveEffectiveHdrMode` was already over the fallow complexity gate on `main` (21 cyclomatic / 25 cognitive / CRAP 462) and only surfaces now because the HLS format work needs to touch its downgrade warning. Pull the downgrade message into `formatDowngradeWarning` and the "which mode and why" info line into `logHdrDecision`, which puts the function under the threshold. No behavior change: every log string is byte-identical and `hdrMode.test.ts` asserts them unchanged. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * feat(producer): add hls output format Adds `format: "hls"` to `@hyperframes/producer`. An HLS render is the same opaque H.264 + AAC encode as `mp4`, stream-copied at assemble time (no re-encode) into a directory: `master.m3u8`, `video.m3u8` + `video_%05d.ts`, and `audio.m3u8` + `audio_%05d.ts` when the composition has audio. The load-bearing part is that `-c copy -f hls` can only cut a segment at an existing keyframe, so the encoder's GOP is locked to `hlsSegmentSeconds x fps` frames. `resolveHlsEncoderGopLock` returns that pair as one value spread into both encoder inputs, so the streaming and disk/chunked paths cannot disagree — a render reaching only one of them still succeeds, it just emits variable-length segments silently. - `renderFormat.ts`: `hls` is opaque (`outputNeedsAlpha` is now `!== "mp4" && !== "hls"` — missing this flips HLS to RGBA screenshot capture with nothing failing), supports page-side compositing, and `outputUsesH264Pipeline` replaces the three `outputFormat === "mp4"` router gates. - `hlsConfig.ts`: `hlsSegmentSeconds` (default 4, positive integer), the GOP derivation, and the fail-fast gates. `force-hdr` is rejected (v1 is SDR-only; HDR10 needs HEVC in fMP4), and so is `useGpu` — the GOP lock is software-only, so a GPU HLS render segments correctly by accident on videotoolbox and wrong on nvenc. - `assembleStage.ts`: `hls` branches to `packageHls` instead of mux/faststart, after the same `padOrTrimAudioToVideoFrameCount` the mp4 mux uses. - `artifactTransaction.ts`: a directory artifact can now carry a `probeTarget` + `requiredFiles`, so the #3395 truncation gate still runs for HLS against `video.m3u8`. `expectedFrames` is inert there (ffprobe reports no frame count through the hls demuxer); duration carries it. - `renderRequest.ts`: accepts `hls` + `hlsSegmentSeconds`; distributed conversion rejects it alongside `gif`. `DistributedFormat` is unchanged. `RENDER_REQUEST_VERSION` stays at 1: the new field is optional, the parser ignores unknown option keys, and an older worker already rejects `format: "hls"` with "Render request format is invalid". - `hdrMode.ts`: the non-mp4 SDR downgrade warning no longer claims "HDR + alpha" for `hls`; the helper extraction landed in the preceding refactor commit. Verified: `hlsRender.integration.test.ts` renders a real 10 s composition and asserts 3 segments, the first two exactly 4.000 s, every segment starting on an IDR frame, and PTS 0. Removing the GOP wiring collapses it to 2 segments, so the test is load-bearing. Both producer lanes (unit and integration) run on every PR in `ci.yml`, so that wiring check is on the PR gate. CLI flags and docs are deliberately left to the next PR in the series. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> * fix(engine): close the HLS master playlist rewrite race CodeQL flagged two high-severity alerts on the `stripAudioOnlyVariants` rewrite: a check-then-use race (`existsSync` then a separate path-based read and write) and insecure creation of a file at a predictable path in the OS temp dir. Both came from resolving `master.m3u8` three times. Open it once with `r+` and owner-only mode — which neither creates the playlist nor widens its permissions, ffmpeg owns that — then read, truncate and write through that one descriptor. Absence is still tolerated for the argument-level tests that stub ffmpeg, now via ENOENT rather than a prior existence check. No behavior change: `hlsRender.integration.test.ts` still renders a real composition with audio and asserts the stripped master playlist. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 (1M context) <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
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 20 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, 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) 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 to install all 20 deliberately (skips the picker), or npx skills add heygen-com/hyperframes --skill <name> for just one (bare name, no leading /).
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), 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










