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Agent Skill

Hyperframes Core

hyperframes-core

The HyperFrames composition contract — build one renderable project. Use for composition structure, the `data-*` timing attributes, `class="clip"`, tracks, sub-compositions, variables, framework-owned media playback, deterministic-render rules, and validation. Also covers Tailwind projects and the STORYBOARD.md / SCRIPT.md plan formats. Read before writing composition HTML.

Heygen ComFrontendTypeScriptAiAnimationFfmpegFrameworkGsapHtmlMcpPuppeteerRenderingTypescriptVideo

265K installs

heygen-com/hyperframes

by Heygen Com

Score

8.8

/ 10

Installs

265K

Repo Stars

40.8K

Last Updated

0d ago

Fresh

Quality Ratio

94%

Description

Verified

Language

TypeScript

First Published

Jun 2026

Summary

The Hyperframes Core agent skill defines the foundational technical contract for rendering dynamic video content directly from HTML, utilizing `data-*` attributes to dictate composition structure, timing, and media playback. This agent skill is essential for frontend developers, animators, and content creators building programmatic video experiences using web technologies like HTML, CSS, and JavaScript, particularly those integrating with Tailwind v4. It is a skill with 5K installs, indicating a significant but specialized adoption within the registry. It provides explicit guidance on composition architecture, distinguishing between standalone and sub-composition structures, and detailing the crucial use of `data-*` attributes for clips, tracks, and variable declaration. The skill enforces a synchronous GSAP timeline contract and outlines critical non-negotiable rules, such as avoiding `Math.random()` or `repeat: -1` for visuals, and requiring media elements to be direct children of the host root. Developers must be aware that several critical layout and media-related rules, if violated, can lead to silent visual bugs that standard linting and validation tools may not detect.

Skill Definition

HyperFrames renders video from HTML. A composition is an HTML file whose DOM declares timing with data-* attributes, whose animation runtime is seekable, and whose media playback is owned by the framework.

This skill is the technical contract — how to build one hyperframes project. The body below is the build guide; per-topic detail lives in references/ (index next), read on demand. Other concerns live in the sibling domain skills — hyperframes-animation, hyperframes-creative, media-use, hyperframes-cli, hyperframes-registry. The capability map in /hyperframes says what each one covers.

References

FileRead it to…
references/minimal-composition.mdstart from the smallest renderable composition skeleton
references/composition-patterns.mdchoose monolithic vs modular; structure a modular index.html; pick a sub-comp archetype
references/data-attributes.mdlook up any data-* (root / clip / sub-comp host / legacy aliases); use class="clip"
references/tracks-and-clips.mdpick data-track-index, handle same-track overlap / z-index, time a clip relative to another
references/sub-compositions.mdwire a sub-composition (host attrs, <template>, per-instance vars) and animate inside it
references/variables-and-media.mddeclare variables; place <video>/<audio>, set volume, trim
references/determinism-rules.mdbuild a seekable timeline; determinism bans; the animatable-property allowlist; layout / text fit
references/full-screen-motion.mdauthor full-frame motion with shared backgrounds
references/storyboard-format.mdauthor a STORYBOARD.md plan (+ the parsed manifest)
references/review-loop.mdrun the plan → sketch → build review passes on a live board — shared by every storyboard-planning workflow
references/production-loop.mdtake an approved plan to a delivered video — the stage dependencies (audio, frames, assembly, transitions, captions, verify, deliver) a freeform build follows directly
references/brief-contract.mdthe brief's ground rules — mode derivation (collaborative / autonomous), shared field registry, question invariants (the asking itself lives in /hyperframes → the intent layer)
references/brief-format.mdauthor BRIEF.md — the confirmed intent document a workflow's Setup writes and every later step reads
references/script-format.mdauthor the optional SCRIPT.md locked narration
references/subagent-dispatch.mdmap subagent dispatch verbs (parallel fan-out / background / wait) to your harness
references/frame-worker-core.mdthe shared frame-worker role contract — each narrative workflow's packet builder prepends it to that workflow's sub-agents/frame-worker.md delta
references/tailwind.mdwork in a Tailwind v4 project (init --tailwind; runtime contract differs from Studio's v3)

For animation runtime specifics (GSAP API, Lottie, Three.js, etc.) go to hyperframes-animationadapters/<runtime>.md.

Building a composition

Two root forms (not interchangeable)

  • Standalone (top-level index.html) — root <div data-composition-id="…"> sits directly in <body>, no <template> wrapper (wrapping it hides all content and breaks rendering).
  • Sub-composition (loaded via data-composition-src) — root must be wrapped in <template>.

⚠ Transport rule: the runtime only clones <template> contents; everything outside (incl. <head> styles/scripts) is discarded — put <style>/<script> inside the template. ⚠ Host-id rule: the host slot's data-composition-id must exactly equal the inner template's data-composition-id and the window.__timelines ["<id>"] key — no -mount/-slot/-host suffix.

File shape, host wiring, and the pre-render checklist → references/sub-compositions.md.

Root must be sized (silent layout bug)

The standalone root needs an explicit sized box (width/height in px), and every ancestor down to a height:100% element must have a resolved height — otherwise a flex/100% child collapses to ~0 and content piles into the top-left corner. Do not rely on automated gates alone to catch this; inspect a snapshot. Skeleton → references/minimal-composition.md.

One paused timeline

Each composition registers exactly one gsap.timeline({ paused: true }) at window.__timelines ["<id>"] (key = root data-composition-id), built synchronously at page load. Render duration = root data-duration, not timeline length. Don't manually nest sub-timelines into the host. Full contract (incl. non-GSAP runtimes) → references/determinism-rules.md + hyperframes-animation/adapters/.

First-pass lint gotchas (a guaranteed first build failure)

Two rules that lint does catch, but only after the fact — write them right the first time:

  • The root composition element must carry data-start="0" (alongside data-composition-id/data-width/data-height); omitting it fails lint with root_composition_missing_data_start.
  • Never pair a CSS initial transform with a GSAP tween on the same property — the CSS value and the tween's start fight and lint rejects it with gsap_css_transform_conflict. Set the initial state inside the tween with gsap.fromTo(el, { x: -40 }, { x: 0 }) instead of a CSS transform: translateX(-40px).

Non-negotiable rules (silent bugs automated gates may miss)

Surfaced here; full rationale in the linked reference. Do not violate:

  • No render-time clocks / unseeded Math.random / network / input-state; no repeat: -1 (use a finite count). → determinism-rules.md
  • Animate only the visual-property allowlist; never tween display or raw visibility. GSAP autoAlpha and zero-duration timeline boundary sets are the only visibility exceptions, and only on non-clip elements or wrappers inside a clip. The framework alone controls .clip visibility. Do not gsap.set later-scene clips at page load. → determinism-rules.md
  • No <br> in body text; transformed elements must be block-level + sized; pulsing absolute decoratives need peak clearance. → determinism-rules.md
  • <video>/<audio> work at any nesting depth (including inside a sub-comp <template> or wrapper); the framework owns playback and seeks/decodes media wherever it lives. The one caveat is timelines, not placement: a sub-comp timeline can't animate host-root elements. → variables-and-media.md
  • Every id must be unique across the assembled page; inside a sub-comp, prefix ids with the composition id (#<id>-hero). Duplicate <video>/<img> ids render blank — the producer injects frames by getElementById, and cross-file dupes slip past lint. → composition-patterns.md
  • A full-screen scene fill goes on a full-bleed child (position:absolute; inset:0), never on the composition root itself — the producer's frame compositing can drop the root element's own background (the frame renders black) even though preview/snapshot show it correctly. → composition-patterns.md

Editing existing compositions

  • Read the files first. Preserve unrelated timing, tracks, IDs, variables, media paths.
  • Match existing composition IDs and timeline keys.
  • Adding a clip: pick a non-overlapping data-track-index or adjust surrounding timing intentionally.
  • data-hidden on any composition element hides it in BOTH preview and render, overriding its time window; it is non-destructive/reversible and toggled by Studio's timeline eye icon.
  • Adding a sub-composition: verify its internal data-composition-id before wiring the host.

Validation

Use hyperframes-cli for command details

  • npx hyperframes check passes (0 findings across lint, runtime, layout, motion, and contrast)
  • Projects with sub-compositions: npx hyperframes snapshot --at <midpoints> and eyeball each frame
  • npx hyperframes preview for review (the user can edit anything in Studio's timeline)
  • npx hyperframes render only after the user approves

How to Use

Use in O-mega

Claude Code

npx skills add heygen-com/hyperframes hyperframes-core