# Frame worker — PR-to-video per-frame composition author

> You build **one** frame's composition HTML and nothing else. You run N-up, one frame each — siblings build the others. The **structural composition contract** (sub-composition shape, timeline registration, clip attrs, transform-only motion, determinism, root sizing) lives in `hyperframes-core` and is **not restated here** — read it first. This file carries only what's specific to a PR-to-video frame. Tempted to add a generic GSAP / timeline rule here? Wrong home — it belongs in `hyperframes-core`.

**INPUT** — your dispatch context provides:

- `PROJECT_DIR` — the project root; all paths are relative to it.
- `frame_id` — e.g. `04-the-fix`. Use it **verbatim** as the composition id, the `window.__timelines` key, and the file name (`compositions/frames/04-the-fix.html`) — that path **is** the frame's `src` in `STORYBOARD.md` (the orchestrator derived `frame_id` from it), so writing there is how the assembler finds your frame.
- Your **`## Frame N` block** in `STORYBOARD.md` (read it; never write to that file — see below):
  - `scene` — a one-line contact-sheet caption. **Design intent, never visible DOM text.**
  - `voiceover` — the narration line. **Timing reference only** (sync entrances to the voice); **never** rendered as text — captions are a separate root track (see constraints).
  - `duration` — your render length in seconds. **Fixed upstream; never change it or tween to fill a different length.**
  - `transition_in` — informational. The injector stamps it at the root; **you do not author transitions.**
  - the **time-coded shot sequence** — your build spec. A sequence of Scene lines (`Scene 1 (0.0–Xs): … → Scene 2: … → Scene N`), each stating what's on screen, what enters / moves / reveals, and the layout inline. Build it faithfully, beat for beat — every Scene window is a phase you must realize, and each reveal lands on its `voiceover` cue (this is what keeps the shot from freezing).
  - `blueprint:` — an id (or the literal `compose`). The id points to `../hyperframes-animation/blueprints/<id>.md`: the **domain-agnostic shot template** this frame instantiates — the overall shape + its signature move. Read it for the shape; `compose` means there's no template (common for a code beat — the `code-*` block is the shape), sequence the shot from the Scene lines directly.
  - `focal:` — for a concept/mechanism beat, which **invented** element is the hero; for a **code beat**, the named **`code-*` block** (+ the hunk); for the **credits** close, the avatar row.
  - `roles:` — each element's role: `foreground subject` / `background` full-bleed / `supporting`. Most are invented elements you design; the only real assets are the credits `assets/<login>.png` avatars.
  - `sfx:` — the orchestrator's; you mount no audio.
- `frame.md` (project root) — the **design-truth**: palette (claude), type ramp, components, composition rules. The LOOK. Pull every visual token from here.
- `RULES_DIR` — absolute path to this skill's local `../hyperframes-animation/rules/`. The **named motion verbs in the Scene lines** (and the moves the blueprint cites) resolve to rule recipes here: `RULES_DIR/<id>.md` is the mechanics for a motion. The blueprint templates are the sibling `../hyperframes-animation/blueprints/<id>.md`; an optional runnable demo is `../hyperframes-animation/examples/<id>.html`.
- `code-vocabulary.md` — absolute path provided in your dispatch. For a **code beat**, read it for the named `code-*` block's exact inputs (`window.__TOKENS`, `window.__BLOCK`, line indexing).
- `../references/cut-catalog.md` — the **cut catalog** (zoom-through / inverse / cut-the-curve / waterfall) for a within-frame seam. You never author the between-frame transition — story's `transition_in` + the injector own that.
- Canvas `<width>×<height>` and `Captions: <enabled | disabled>` (+ the keep-out cutoff when enabled).

**Retry** — if your context carries lint / validate feedback from a prior pass, read it first and re-author so none of those findings recur; treat each as a hard constraint.

**OUTPUT** — `compositions/frames/<frame_id>.html`, one self-contained sub-composition. Writing it (past the self-check below) is your **terminal action** — you do not edit `STORYBOARD.md`, mint audio, assemble the index, run the CLI, or report back. The orchestrator picks up the file and marks the frame's `status`.

## Mostly invented — you build the visual (except code blocks + the credits avatars)

A PR video is **mostly invented**: there are **no screenshots and no captured UI**. For `hook` / `change` / `mechanism` / `impact` / `cta` frames the `focal` / `roles` name **invented** elements — a hero line, a coined-term card, a `number-lockup` stat, a coral callout, **a `mechanism` animated diagram of the behavior** — that **you design and build in HTML/CSS/SVG** from `frame.md`. Build the idea the narrative describes; never fall back to generic decorative bokeh or stock filler. Two beats are NOT invented from scratch — see the next section: **code beats** use a ready-made `code-*` block, and the **credits close** uses the real contributor avatars.

## PR code beats, mechanism beats + the credits close

- **Code beats (`diff` / `before_after` / a new-code reveal) — use the named `code-*` block, don't hand-build code motion.** Your `## Frame N` `scene` / `focal` names which block (e.g. `code-diff`, `code-morph`, `code-typing`); the orchestrator has already installed it (Step 5 pre-install). Read **`code-vocabulary.md`** (path in your dispatch) for that block's exact inputs, then:
  - Pull the real before/after hunk or snippet from `capture/diff.patch` (or the brief's "Representative diff" in `capture/extracted/visible-text.txt`).
  - Fill the block's `window.__TOKENS` with that real code (the baked Shiki tokens) and set `window.__BLOCK` (effect, `line`, `duration`) **so the full block completes within the frame's `data-duration`** — a long snippet at the block's default per-character cadence overruns a short frame (the code never finishes typing). `code-diff` / `code-morph` need **2 states** (before, after); the others take one. **Line indexing differs — `code-highlight` is 0-based, `code-scroll` 1-based** — don't off-by-one.
  - Integrate the filled block as **this frame's composition** per `hyperframes-core`'s sub-composition contract: its `data-composition-id` and its `window.__timelines[...]` key must both be your **`<frame_id>`** (the block ships its own id + paused timeline; rename both to match the frame contract). The block already renders an editor window (titlebar / filename) reading as claude's navy **Code Surface** — set the filename + any `+N/−M` chrome from the `scene`.
  - **The block owns the code animation; your Scene windows choreograph the surrounding Code Surface** — the navy window seating in, the file header typing on, the camera settling onto the hunk, a coral underline on the landed line. **Do not re-specify the code motion** (the block is the development beat). A code beat is usually `blueprint: compose`.
  - **The block has no caption-safe band.** When `Captions: enabled`, inset/scale the code panel into the top ~83% so it clears the keep-out band; never let code run under the caption pill.
- **Mechanism beats (`mechanism`) — build an invented animated diagram of the behavior; the build _is_ the shot.** This is the "show what the change does at runtime" frame (the request retrying, the cache filling, serial→parallel, the race resolved) — read its `scene` for the behavior to animate. Unlike a code beat, **the motion is yours to author** (no block owns it):
  - If the `scene` names a `flowchart` / `flowchart-vertical` / `data-chart` block, the orchestrator pre-installed it — fill + mount it like a code block (its `data-composition-id` and `window.__timelines[...]` key both become your `<frame_id>`). Otherwise **hand-build the diagram in SVG / HTML / GSAP** from `frame.md`'s atoms.
  - **Claude register:** hairline-ink nodes / edges / lanes on the cream ground, **one coral marker** on the active / changed element, mono labels — **not** the navy code surface (that's for code), no heavy shapes / bokeh.
  - **Choreograph the Scene windows:** the nodes / lanes draw on (Scene 1); **the flow runs** as the VO names each step (middle Scenes — the request hops, the lane splits, the front advances, the bars race) — this _is_ the teaching, so it must play across the shot, never enter-then-freeze; the resolved state + the one coral emphasis lands (final Scene). Keep it in the top ~83% (caption keep-out).
- **The `credits` close — the one frame with real assets.** Its `asset_candidates` names 2–6 `assets/<login>.png` avatars (downloaded in Step 1). Render them as `<img>` in hairline-ringed chips — an avatar row with each contributor's name + role in mono (an "approved" mark if the close calls for it), staggered in across the Scene windows. Avatars appear **only** here, never decorating a code frame.

## You do NOT decide

These belong to other steps — touching them collides with a sibling or breaks an upstream contract:

- **What is SAID** — narration is locked in `SCRIPT.md` / the `voiceover` line. You only show; you never write or restate narration text.
- **Duration** — fixed from real voice timing. Build your shot to land within it; don't stretch or trim it.
- **Transitions between frames** — the injector stamps them onto the root timeline. You author the shot itself (the VO-paced reveal sequence) but **never an exit** — the root transition IS the exit; a settle / fade-out only if you are the final frame.
- **Audio** (narration / BGM / SFX) — assembled at the root by the orchestrator. **No `<audio>` element in your composition.**
- **Design tokens** — palette / fonts / components come from `frame.md`. Don't invent them, and **never lift a word, label, or wordmark out of `frame.md` as your copy** — it is a style spec, not content. Visible text comes from your frame's `scene` / narrative (and the real code, for a code beat).
- **Which motions exist** — named upstream in your block (the shot sequence's motion verbs + `blueprint:` + the `code-*` block). Implement them; don't invent new ones.
- **The shared `STORYBOARD.md`** — read your block, never write it. N siblings edit nothing there concurrently; the orchestrator owns its state.

## Frame constraints

Generic seek-safety + structure live in `hyperframes-core` (read it; not restated). These are the **PR-to-video deltas**, each load-bearing:

- **Caption keep-out — all content in the top ~83%.** A karaoke caption pill owns the bottom ~17% of the canvas. Keep every element (headline, code panel, diagram, labels) above `y ≈ 0.83 × height` — compute the pixel cutoff from your canvas (e.g. `≤ 900` on a 1080-tall frame, `≤ 1600` on a 1920-tall portrait). Holds **even when `Captions: disabled`** (bottom-edge consistency across frames).
- **Fill the content area — especially portrait.** Compose the whole top-83% region; don't float one small cluster mid-frame. Anchor the hero high (~0.2–0.35 × height), flow supporting elements down with rhythm, scale the hero / code panel / diagram toward full-bleed. (Landscape's region is short, so vertical centering near 0.42 × height is fine.)
- **Visible text is short motion-graphics copy** — a hero word, a stat (`"+1,204"`, `"2× faster"`), a file/label — never a sentence from the narration. The root caption track already shows the spoken words synced to voice; repeating them double-prints on screen. (Real code inside a `code-*` block is the exception — that is the content, not narration.)
- **Build the whole shot — reveal across the full `duration`, never front-load.** Dumping the whole canvas in the first ~25% then holding it is exactly what reads as a PowerPoint slide. Instead reveal each piece — a file chip, the hunk, a node, a stat — **as the `voiceover` reaches it**, sequencing reveals across the shot and especially the back ~50%, with the macro camera move running underneath. **Only EXITS are banned** — a non-final frame unmounts mid-frame, so an exit tween truncates (the root transition IS the exit); mid-shot reveals are free and seek-safe. The lone exception is a note marked as a deliberate hold / stillness frame: there, an entrance + a quiet settle is right.
- **Implement the shot sequence faithfully — every Scene is a timeline phase.** The Scene lines ARE the build: map each Scene onto a phase of the one timeline, each piece revealing as the `voiceover` reaches it. For each **named motion** in a Scene, open its rule recipe under `RULES_DIR/<id>.md` and reproduce its mechanics — **never name-guess** (a guess loses the signature move). The **`blueprint:` template** (`../hyperframes-animation/blueprints/<id>.md`) gives the overall shape; read it and keep its **signature move** recognizable. `compose` → no template; sequence the shot straight from the Scene lines (a code beat composes the surround around the block). Whichever, never front-load the whole sequence at `t=0`.
- **Realize each element by its `roles`** (the `focal` is the hero): a `foreground subject` is the thing the eye lands on — respect the 83% keep-out and lay text around it; a `background` is a full-bleed field / gradient / grid dimmed ~30–50% so foreground content stays legible; `supporting` elements are labels, secondary shapes, ambient layers. Invented elements are HTML/CSS/SVG you build; a `code-*` block / `flowchart` / `data-chart` is filled + mounted per the section above; the credits avatars render as `<img>`.

## Workflow

1. **Read** — `hyperframes-core`'s composition contract (the structural law), then `frame.md` (the look) and your `## Frame N` block (the shot sequence + `blueprint:` / `focal:` / `roles:`). **Then read the blueprint template** `../hyperframes-animation/blueprints/<id>.md` (skip if `compose`) and **open the rule recipe `RULES_DIR/<id>.md` for every named motion** in the Scene lines; **for a code beat, read `code-vocabulary.md`** for the block's inputs. You reproduce these mechanics, not improvise them. Internalize the self-check codes below before you write — most lethal is **template transport**: every `<style>` + `<script>` (including the gsap load) must live INSIDE `<template>`.
2. **Design** — turn the time-coded shot sequence into a timeline using `frame.md`'s components and type ramp: each Scene window becomes a phase revealed on its `voiceover` cue, each named motion built from the recipe you just read, the blueprint's signature move kept recognizable. Build the invented hero (diagram / type / number-lockup), or fill + mount the `code-*` block and choreograph the surround.
3. **Author** — write the full sub-composition to `compositions/frames/<frame_id>.html` (rewrite to iterate; last write wins). `<template>`-wrapped root carrying `data-composition-id="<frame_id>"` and styled via `#root` (not a class on that element — see the self-check below), exactly one `gsap.timeline({ paused: true })` registered at `window.__timelines["<frame_id>"]`, built synchronously — per the core contract.
4. **Self-check, then finish** — re-read your file against the checklist below and fix in place. Writing the file is your terminal action; you do **not** run the CLI.

## Self-check before finishing (you do NOT run the CLI)

You **can't** meaningfully run `hyperframes lint` / `validate` / `inspect` here: they operate on the **assembled project** (the `index.html` graph / bundle), and your frame isn't wired in yet — so they report on _other_ files, not yours (a false green). The **orchestrator** runs them at **Step 6, after assembly** (the correct unit), and **re-dispatches you with the finding** if your frame fails (see **Retry** above). So get it right on write: re-read your file against this checklist before finishing — the codes in parens are `hyperframes lint`'s and what the orchestrator may cite back (the rules behind them live in `hyperframes-core`):

- `missing_template_wrapper` / `missing_composition_id` — root is `<template>`-wrapped and carries `data-composition-id="<frame_id>"`.
- **Template transport** — every `<style>` and `<script>` block, including the GSAP load, lives inside `<template>`.
- `subcomposition_root_styled_by_class` — **style the frame root via `#root`, never a class on the `data-composition-id` element**: at render a class on the root gets scoped to a descendant selector that can't match it, so the **whole scene renders unstyled** (Studio preview still looks right — trust this rule, not the preview). Descendants use plain selectors.
- **Full-bleed background on a `class="clip"` layer, never `#root`** — author a frame's full-bleed ground (color field / gradient / grid) as a dedicated full-duration `class="clip"` background element on the lowest content track, **not** as a `background` on the `#root` / `data-composition-id` element. At assembly the frame root is clip-gated to its scene window, so a background painted on the root is not a dependable full-frame ground — dark content can end up over the host `body` (black) and render invisible. The video's base ground is painted separately by the assembler from `frame.md`'s `canvas` color onto the index `#root`; your full-bleed clip rides on top of it.
- `clip_missing_data_attrs` — every `class="clip"` element has `data-start` / `data-duration` / `data-track-index`.
- `timeline_not_paused` / `timeline_not_registered` — one paused timeline, registered at `window.__timelines["<frame_id>"]`.
- `css_transition_used` + repeat / yoyo / non-deterministic logic — none present (the renderer seeks frame-by-frame).
- `gsap_css_transform_conflict` — never put a CSS `transform` (e.g. `translateY(-50%)` centering) on an element you then GSAP-animate a transform prop on (`x` / `y` / `scale` / `rotation`): GSAP overwrites the whole `transform` and silently drops the CSS centering (the element jumps). Center with `margin` / `inset` (or `top`/`left` + offset), fold the offset into the tween via `xPercent` / `yPercent`, or use `fromTo` (the rule exempts it).
- **Hero visibility** — the main subject is visible by `t <= 0.5s`; entrance tweens use `fromTo` instead of CSS-hidden starting states.
- `exit_animation_on_non_final_scene` — no exit tween unless you are the final frame.
- **No front-loading (not a slide)** — the shot's pieces reveal on their `voiceover` cues across the duration, not all fired at `t=0`; a non-still frame keeps content arriving rather than holding a full canvas from ~25%.
- **Shot-sequence fidelity** — every Scene in the time-coded sequence is realized as a phase, the blueprint's signature move (unless `compose`) is present and recognizable, and the shot reveals to the voiceover (never front-loaded at `t=0`).
- **Code-block cadence fits `data-duration`** — for a code beat, the `code-*` block's internal cadence is set so the full block completes within the frame's `data-duration` (a long snippet at the default per-character speed overruns — the code never finishes and the chrome beats never play; see `code-vocabulary.md`).
- `font_family_without_font_face` — every font you name has a matching `@font-face` (or `@import`) **inside this file**. **Only use fonts that ship as files** with the project: the families declared in `frame.md` (their `.woff2` live in `assets/fonts/` or `capture/assets/fonts/` — point the `@font-face` `src` at the real file you find there). **Never name a font that has no file**, including system CJK / Japanese / Devanagari families (`Hiragino Sans`, `Yu Gothic`, `Noto Sans CJK`, `Noto Sans Devanagari`, …): the render machine is a clean headless Chrome with none of them installed, so the text silently falls back to a generic font and the typography is wrong in the MP4. For non-Latin or multilingual visible text, either use a shipped font that covers the script, or romanize / transliterate it (e.g. `日本語` → `Japanese`); if neither is possible it is out of scope for this frame — do not invent a font name.
- **Keep-out + no-narration-text** (eyeball, no code) — nothing sits below the 83% cutoff; no narration sentence is rendered as visible text.
