* fix(player): inject runtime immediately for nested compositions Compositions that use `data-composition-src` on child elements require the HyperFrames runtime to load those scenes — there is no way for the iframe to render without it. The existing probe loop delayed runtime injection behind a 5-tick attempts gate so the adapter path could try to resolve a timeline first. For nested compositions that race lost: a composition like the `product-promo` registry example registers an inline pre-runtime GSAP timeline at `window.__timelines["main"]` (covering only a partial duration, e.g. 14s of a 20s master) while the iframe document loads. The probe's adapter check finds that timeline and locks the player into a "ready" state against it — which short-circuits the attempts gate and the runtime never gets injected. The iframe ends up blank because the runtime is what would have loaded the child scenes via `data-composition-src`. This change splits the injection decision into a pure helper, `shouldInjectRuntime(state)`, and treats nested compositions as "inject immediately, skip the gate." Self-contained GSAP-only compositions retain the 5-tick grace period so the adapter path keeps first shot for them. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * fix(core): propagate play/pause to all sibling timelines Pausing or playing the master timeline only called `.pause()` / `.play()` on `state.capturedTimeline` — the single adapter-selected timeline. In a nested composition (a master with `data-composition-src` children), each scene's own timeline is registered as a sibling in `window.__timelines`, so they would keep advancing after the user clicked pause. The player UI froze at the paused time while the visual content continued to animate, eventually finishing all scene-level animations and landing on an empty end-state. Wire `window.__timelines` into the runtime player via a new `getTimelineRegistry` dep, iterate the registry on play/pause, and forward `timeScale` to siblings when play() starts so a changed playback-rate applies uniformly. Covered by 7 new unit tests in player.test.ts, including the identity- equality check (don't double-invoke the master), playbackRate propagation, a broken-sibling swallow, and a back-compat case with no registry supplied. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.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 and GSAP animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for CLI commands, and /gsap for animation help.
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 |
CLI commands: init, lint, preview, render, transcribe, tts, doctor |
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 |
gsap |
GSAP animation API, timelines, easing, ScrollTrigger, plugins, React/Vue/Svelte, performance |
Contributing
See CONTRIBUTING.md for guidelines.
