ukimsanov 0730f88dc7 fix(cli): address snapshot PR review feedback
Incorporates four review points on #348:

1. Fix typecheck error — cast the dynamic `@hyperframes/engine` import to a
   typed shape and drop the `as typeof x` cast on a `null`-unioned variable
   that TS rejected. CI `Typecheck` was failing on main because the cast
   conflicted with the declared union.

2. Clear stale injected <img> overlays — always call
   `syncVideoFrameVisibility(page, activeIds)` on every seek (including
   `active.length === 0`), so injected frames from a previous timestamp
   don't leak into later snapshots. The runtime's visibility toggles act
   on the native <video> but not on its injected sibling, which Copilot
   correctly flagged as a leakage source.

3. URL-decode the served video path before resolving to a filesystem path.
   Files whose names contain spaces or other URL-encoded characters were
   skipped because `new URL().pathname` preserves `%20` while the file
   server decodes inbound requests and the file on disk lives at the
   decoded name.

4. Mirror `packages/core/src/runtime/media.ts` media math so clips with a
   non-1 `defaultPlaybackRate` get the correct active window and relTime.
   Specifically: clamp `defaultPlaybackRate` to [0.1, 5], apply
   `(t - start) * rate + mediaStart`, and adjust the duration-fallback
   branch by `/ rate` when only source duration is known.

5. Kill FFmpeg on a 30s timeout so a pathological clip cannot wedge
   snapshot indefinitely. Matches the default in
   `@hyperframes/engine`'s `runFfmpeg`.

Re-verified against the same 4-timestamp A/B on launch-video-2:
MD5s match the ffmpeg-from-render ground truth
  12.5s → ef9684e36fea53a0db7adf7cfcaacad3  (Stripe)
  16.0s → 487494ca16344d55d7181408dc439a56  (Framer)
  20.5s → 8835c34ad2a45755a1c98a7e079427a1  (HeyGen 3D)
  32.5s → 34dc9450f2bd661c12039d7aa82a30b0  (GitHub finale)

No-video projects (basecamp-tour, linear-brand, commissioned/github)
still produce identical output to the pre-fix path. Latency unchanged.

Made-with: Cursor
2026-04-20 10:30:29 -04:00
2026-03-21 22:43:56 -07:00

HyperFrames

npm version npm downloads License Node.js

Write HTML. Render video. Built for agents.

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

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

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).

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/introductionQuickstart | 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.

License

Apache 2.0

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