Caro demo video

Caro Demo Video

Reproducible, on-brand product demo video for the caro website, rendered from React code via Remotion. This skill covers the full lifecycle: build → render → ship → detect drift → re-render.

When to Use

• "create the project demo video"
• "render a new caro demo"
• "update the landing page video"
• "add a new scene to the demo"
• "the demo on the website is missing / outdated"
• "the caro-demo-drift workflow flagged my PR — what now?"
• A beads task with label caro-demo-video is in your bd ready queue

What This Skill Owns

The Remotion project at demos/remotion-video/ and its rendered output at website/public/caro-demo.mp4 (+ caro-demo-poster.png). Wired into website/src/components/landing/LPVideoDemo.astro via videoUrl / posterUrl props passed from website/src/pages/index.astro.

Companion Skill

This skill is operational. For Remotion mechanics (animation curves, timing, fonts, transitions, audio) load the global remotion-best-practices skill at ~/.claude/skills/remotion-best-practices/. Specifically rules/compositions.md, rules/timing.md, rules/transitions.md, and rules/fonts.md cover everything you'll need.

Style Rules

These are caro-specific and not covered by remotion-best-practices.

Visual tokens (mirror of website/src/ui/tokens.css)

Token	Hex	Use
bgDeep	#0a0a0f	Composition background
bgTerminal	#1a1a2e	Terminal window body
bgChrome	#16161c	Terminal title bar
borderSubtle	#1e1e24	Window border
accent	#ff8c42	Caro suggestions, primary CTA
accentDark	#ff6b35	Hover states, secondary brand
prompt	#4ec9b0	Shell prompt $
command	#9cdcfe	Typed command text
success	#22c55e	Safe / passed indicator
danger	#ef4444	Blocked / error indicator
warning	#f59e0b	High-risk warning
textPrimary	#e0e0e0	Body text on dark bg
textMuted	#a0a0a0	Captions, secondary text

Mirror these in demos/remotion-video/src/tokens.ts. Do not import the website CSS — the Remotion build is isolated.

Typography

• Body / captions: system-ui sans-serif stack
• Terminal: 'SF Mono', 'Monaco', 'Cascadia Code', 'Fira Code', monospace
• Letter spacing in terminal: 0 (default monospace metrics; do not condense)

Window chrome (from LPDemo.astro)

macOS traffic-light dots:

Dot	Color
Close	#ff5f56
Minimize	#ffbd2e
Maximize	#27c93f

Title bar background #16161c, 12px padding, dot diameter 12px, gap 8px.

Authenticity rules

1. Never invent commands. Pull queries + expected outputs from .claude/beta-testing/test-cases.yaml. If you need a query that isn't there, add it to the test fixture first and verify it passes against the current caro binary, then use it in the demo.
2. Match the real terminal output. Caro prints the bare command on stdout and metadata (risk, confidence) on stderr — see src/main.rs around lines 1014–1023 for the literal block messages.
3. Use real install commands. cargo install caro and brew install wildcard/tap/caro. No marketing pseudo-syntax.

Scaffold

The Remotion project lives at demos/remotion-video/. Structure:

demos/remotion-video/
├── package.json           # remotion, @remotion/cli, react, react-dom
├── remotion.config.ts     # 1920x1080 @ 30fps, h264
├── tsconfig.json
└── src/
    ├── index.ts           # registerRoot(Root)
    ├── Root.tsx           # <Composition id="CaroDemo" durationInFrames={900} />
    ├── CaroDemo.tsx       # <Series> of scenes
    ├── tokens.ts          # color + font tokens
    ├── components/
    │   ├── TerminalWindow.tsx
    │   ├── TypewriterLine.tsx
    │   └── Caption.tsx
    └── scenes/
        ├── ScenePain.tsx
        ├── SceneQueries.tsx
        ├── SceneSafety.tsx
        └── SceneCloser.tsx

Total duration: 900 frames @ 30fps = 30 seconds.

Scene Cadence

#	Scene	Frames	Duration	Caption	Terminal action
1	ScenePain	0–119	4s	"Forgot the syntax. Again."	Cursor blinks; # how do I find... types in then trails off
2	SceneQueries	120–539	14s	Per-query badge: 0.3s · 100% local	3 caro queries from test-cases.yaml render back-to-back, ~4.5s each
3	SceneSafety	540–779	8s	"52+ patterns. Blocked before damage."	caro "delete everything in the current directory" → red ✗ command blocked by safety validator (Critical)
4	SceneCloser	780–899	4s	"Local. Private. No API key."	Logo + cargo install caro install line

Scene 2 queries (verified against .claude/beta-testing/test-cases.yaml):

1. caro "find all PDF files larger than 10MB in Downloads" → find ~/Downloads -name "*.pdf" -size +10M -ls
2. caro "find python files modified last week" → find . -name "*.py" -type f -mtime -7
3. caro "find all errors in application logs" → grep ERROR logs/app.log

Build Workflow

# 1. First-time scaffold (skip if demos/remotion-video/ already exists)
cd demos/remotion-video
npm install

# 2. Iterate
npx remotion preview
# → opens Remotion Studio at http://localhost:3000
# → hot reloads on file save; tune timing visually

# 3. Render the MP4 + poster
npx remotion render CaroDemo \
  ../../website/public/caro-demo.mp4 \
  --codec=h264 --crf=23 --image-format=jpeg

npx remotion still CaroDemo \
  ../../website/public/caro-demo-poster.png \
  --frame=60

# 4. Verify in the website
cd ../../website
npm run dev
# → load http://localhost:4321/, scroll to "30 Seconds to Terminal Mastery"

Wiring

The slot is LPVideoDemo.astro and is rendered from website/src/pages/index.astro (around line 23). Pass:

<LPVideoDemo
  videoUrl="/caro-demo.mp4"
  posterUrl="/caro-demo-poster.png"
/>

When videoUrl is truthy the placeholder swaps for <video controls>. The component is already styled — no CSS edits needed.

The same MP4 is English only (root /). Non-English locales render Video.astro (asciinema embed) instead — leave those untouched unless explicitly extending scope.

Render Quality Targets

Setting	Value	Why
Resolution	1920×1080	Retina-friendly, standard hero
FPS	30	Web-safe; 60 doubles file size for no perceived gain on text-heavy demo
Codec	h264	Universal browser support, small file
CRF	23	Visually lossless for terminal text; bigger CRF (lower) bloats text-heavy frames quickly
Audio	none	Silent demo; site has <video controls> so users opt in to play anyway
File size target	< 6 MB	Hero asset budget — re-encode if larger

Update Workflow (when caro changes)

1. Re-run each Scene 2 query against the current caro binary; if any command drifted, update .claude/beta-testing/test-cases.yaml first to keep the test fixture authoritative.
2. Update the typed line in SceneQueries.tsx (and SceneSafety.tsx if the safety message text changed in src/main.rs).
3. Re-render and re-ship per the Build Workflow above.
4. Bump the version number in the demo's title bar (e.g. caro v1.4.0 — demo) only if a major release dropped.

Drift Detection

The video bakes in mutable facts: brand colors, terminal chrome design, real CLI output strings, the "52+" pattern count, install commands. These come from 7 specific files. Drift between those files and the shipped MP4 means the video is lying about the product.

Baseline manifest

demos/remotion-video/.baseline-manifest.json is the source of truth. It records:

1. Tripwire SHAs — SHA-256 of each watched file at the last successful render. Mechanical, cheap to check.
2. Semantic claims — the actual scene-text strings baked into the video: pattern count, install command, block message, the three Scene 2 query/output pairs, the Scene 3 query. So the next agent reading the manifest can see at a glance what the video says, without having to re-derive it from the source code.

Watched files (7)

File	Why it matters	Affects
website/src/ui/tokens.css	Brand palette	All scenes
website/src/components/landing/LPDemo.astro	Terminal chrome design	All scenes
src/main.rs (lines ~1014–1023)	CLI block-message string	Scene 3
.claude/beta-testing/test-cases.yaml	Verified caro queries + outputs	Scene 2
src/safety/patterns.rs	Pattern count (currently 52)	Scene 3 caption
homebrew-tap/README.md	Install command	Scene 4
install.sh	Curl-pipe install	Scene 4

Run the check

demos/remotion-video/scripts/check-drift.sh --human

Exit codes: 0 no drift, 1 drift detected, 2 tooling error. Default output is JSON; --human is for terminals.

Triggers (how an agent gets here)

Three independent channels — at least one will catch drift:

1. CI watcher (path-filtered) — .github/workflows/caro-demo-drift.yml runs check-drift.sh on every PR that touches a watched file. If drift is detected, the workflow comments on the PR with the specific files that changed and links here.
2. Monthly cron — a scheduled beads task (label caro-demo-video) forces a fresh check even when no PR touched a watched path. Catches slow brand drift over many small commits.
3. Manual / human-triggered — anyone can run the check script and file a beads task tagged caro-demo-video.

Trust Model — when can an agent ship without human review?

The re-rendered MP4 is a public-facing marketing asset. Two paths:

Drift type	Examples	Required action
Output-equivalent	tokens.css color literal renames (e.g. variable rename, same hex value); whitespace-only changes in LPDemo.astro; install.sh comment edits	Agent re-renders and ships directly. Visual diff against the prior poster.png must be within ±5% pixel delta.
Cosmetic but visible	Hex color value changes; LPDemo chrome restyle; new pattern count claim ("52+" → "60+")	Agent renders, opens a PR with the new MP4 + poster, requests human review.
Semantic	Scene 2 query strings drift; block message changes; install command changes	Agent renders, opens a PR with side-by-side commentary (old vs new strings), requests human review. Do not auto-ship.

The agent decides which bucket applies by reading the claims_baked_into_video section of the manifest against the current working tree. If a query string in test-cases.yaml changed, that's semantic → PR. If only a hex value changed in tokens.css, that's cosmetic-but-visible → PR. If nothing semantic changed and the render is byte-identical, the agent may push directly to main.

Claiming a Maintenance Task

This skill is agent-claimable. A Claude Code session reaching this section should:

1. Check the trigger.
   • Beads task in bd ready with label caro-demo-video → read bd show <id> for the trigger note.
   • PR comment from caro-demo-drift workflow → read the comment for the drifted-files list.
   • Manual invocation → run check-drift.sh --human for the report.
2. Decide the trust bucket from the table above.
3. Re-render with demos/remotion-video/scripts/render-and-ship.sh — this also refreshes the baseline manifest, so subsequent drift checks anchor to this render.
4. Ship per trust bucket:
   • Output-equivalent: commit + merge directly.
   • Cosmetic / Semantic: open a PR with the rendered MP4 + poster + refreshed manifest, request human review.
5. Close the beads task with bd close <id> --reason="re-rendered <reason>; commit <sha>".

If unable to complete (e.g. queries failed when verified against the current caro binary, terminal chrome rebuild needed), keep the task in_progress and add a comment explaining what's blocking, so the next agent (or a human) can pick up.

Out of Scope (track separately if requested)

• Voiceover audio — the remotion-best-practices skill covers ElevenLabs TTS at rules/audio/voiceover.md if needed
• Localized text overlays — current MP4 is English; per-locale text would require either separate renders or runtime SVG overlays
• Lambda / cloud rendering pipeline — local npx remotion render is fast enough for a 30s clip (~30s render time on M-series)
• A second longer-form demo (1–2 min "deep dive") — would need its own composition + scene set