Miguel Ángel 9bb4b4ce60 fix(lint): break two fix-loops and drop two rules the runtime owns (#3400)
An eval of time-to-finished-video against Remotion found the whole gap sits
after authoring, in the lint/check -> fix -> recheck loop. Lint execution is
3-5% of wall; the cost is the model turn each finding triggers. So the
expensive rule is the one an agent cannot satisfy, and the next most expensive
is the one that fires on correct code.

Two rules could not be satisfied at all.

`gsap_fullscreen_overlay_starts_visible` on a from() reveal was a closed cycle.
It errored on `tl.from("#flash", { opacity: 0 })`, which is not a defect:
from() seats its start values immediately, so on a paused timeline the overlay
already measures opacity 0 at t=0. Both of its fixHints (authored CSS
`opacity: 0`, or an immediate `gsap.set`) turn that working composition into a
real defect, which `gsap_from_opacity_noop` correctly errors on -- and that
rule's fixHint says to remove the very thing we just asked for. Applying either
hint bounced between the two errors forever.

The root cause was not the reporting condition but `laterHidden`, which counted
the reveal itself: a from-tween records its START values, so
`from({opacity: 0})` read as its own later hide. Excluding the reveal, and
excluding from-tweens (which end visible), is what actually fixes it. The
later-hidden shape still reports and still converges.

`caption_text_overflow_risk` told authors to add `overflow: hidden`, which is
exactly what `caption_overflow_clips_scaled_words` errors on. Following the
warning produced an error. The hint now says to keep overflow visible.

Two rules asserted a failure that cannot happen.

`root_composition_missing_data_start` errored because "the runtime needs
data-start=0 on the root element to begin playback". The runtime sets it itself
-- init.ts:286-292, whose comment reads "Agents sometimes omit data-start on the
root composition element ... Default to 0 for the root." The rule demanded the
fix the runtime had already applied. 16 of the 643 shipped registry files.

`overlapping_clips_same_track` claimed overlapping clips "cause rendering
conflicts". Nothing reads the track index at render: timeline.ts:586 states
"Track index is display-only; render never reads it", and grepping
`trackIndex|track-index` across engine and producer source returns zero hits.
Two clips overlapping on one track is a crossfade.

Two false positives fixed rather than removed, because the invariants are real.

`timeline_id_mismatch` fired on the legal one-liner
`window.__timelines = { main: gsap.timeline({ paused: true }) }`. The body regex
was non-greedy, so it stopped at the brace of the inlined OPTIONS object, and
the entry scanner harvested `paused` as a composition id. The resulting fixHint
named a registration that does not exist, so it could never be applied; hoisting
to a variable was the only escape and nothing said so. It now walks brace depth
and reads top-level keys only.

`non_deterministic_code` fired on `new Date("2026-01-01T00:00:00Z")`, which is
deterministic, and on `Math.random()` inside a string literal that a code-display
composition renders but never executes. Date is now zero-arg only, and patterns
run against string-stripped source -- except the GSAP `"random(...)"` tween
value, where the string IS the executed value and must still be scanned. That
exception is what the first attempt got wrong; the existing tests caught it.

Measured over the 643 shipped registry files: 386 -> 370 errors, no new codes.
The corpus does not exercise the loop cases, so it understates the change -- the
point is the turns those loops cost, not the finding count.
2026-08-21 15:15:12 -04:00
2026-08-20 21:47:29 -07:00
2026-03-21 22:43:56 -07:00

HyperFrames

npm version npm downloads License Node.js Discord

Write HTML. Render video. Built for agents.

Quickstart | Showcase | Playground | Catalog | Docs | Discord

HyperFrames demo: HTML code on the left transforms into a rendered video on the right

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 /hyperframes router installs each creation workflow on demand. Agents and non-interactive runs should use npx hyperframes skills update instead — it installs exactly the core set, whereas a non-interactive skills add without --skill installs all 20.

skills add resolves the skills.sh registry blob, which can lag main by hours. npx hyperframes skills update installs from the current main, 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), 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
Biennale Yellow
BlockFrame
BlockFrame
Blue Professional
Blue Professional
Bold Poster
Bold Poster
Broadside
Broadside
Capsule
Capsule
Cartesian
Cartesian
Cobalt Grid
Cobalt Grid
Coral
Coral
Creative Mode
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.html composition 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.

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

License

Apache 2.0

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Write HTML. Render video. Built for agents.
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