Adds a full annotation pipeline to /impeccable live. On Go, the browser
captures the selected element as a PNG (with annotations composed in),
uploads it to the live helper, and sends the generate event with the
screenshot path so the agent reads user intent visually instead of from
HTML alone.
Annotation tools (while an element is picked):
- Click inside the outline to drop a magenta comment pin with a text input
- Drag to paint a magenta SVG stroke (5 px click-vs-drag threshold)
- Click a pin to edit; double-click to delete; drag a pin to reposition
- Click a stroke to delete it (wider invisible hit path)
- Clear chip top-right wipes everything; hidden when no annotations
Capture pipeline:
- modern-screenshot vendored as an IIFE (scripts/modern-screenshot.umd.js)
and lazy-loaded from the live helper
- Font fix: cross-origin @font-face rules are fetched and fonts are inlined
as base64 data URIs before being handed to modern-screenshot via
font.cssText, since SVGs rasterized via canvas can't fetch external
resources (fix for "Impeccable" rendering bold-serif and items wrapping
wrong in the capture)
- Annotations are temporarily attached to the live element (not only the
clone) so computed styles resolve during the embed pass
- Session screenshots live in .impeccable-live/annotations/session-*/ in
the project root (gitignored) so the agent's Read tool doesn't trip a
per-path permission prompt
Loading shader (activates during GENERATING):
- WebGL overlay rendering the captured PNG as a halftone — cells with
luma-driven dot radius, rendered on paper-cream underneath a magenta
roller that sweeps top-to-bottom with a 3.4s cycle and clean overshoot
- Fixed asymmetric bandAt() using one-sided smoothsteps (previous reversed
smoothstep was undefined on d>0, giving "trail=1 everywhere below")
- Graceful <img> fallback when WebGL is unavailable; prefers-reduced-motion
freezes the band at t=0
Server:
- POST /annotation endpoint (raw image/png body, token + eventId query),
session-scoped tmpdir cleaned up on shutdown
- GET /modern-screenshot.js serves the vendored UMD with aggressive caching
- Optional screenshotPath / comments / strokes fields on generate events
- Fixed pre-existing /source crash on ENOENT (writeHead called twice)
Agent side:
- reference/live.md step 0 tells the agent to Read the screenshot first,
with four rules for interpreting annotations: comments are position-
anchored and scoped to the sub-element under their {x,y}; strokes are
gestures (loop=focus, arrow=direction, cross=delete); comments and
strokes are independent unless adjacent; don't silently guess on
ambiguous strokes
Also:
- Generating bar no longer claims "Generating 1 of 3..." (variants arrive
atomically) — now says "Generating N variants..."
- tests/live-server.test.mjs fixed to read the PID file from project root,
matching the server; adds coverage for the new endpoints and validator
fields
- .impeccable-live/ added to .gitignore
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Impeccable
The vocabulary you didn't know you needed. 1 skill, 23 commands, and curated anti-patterns for impeccable frontend design.
Quick start: Visit impeccable.style to download ready-to-use bundles.
Why Impeccable?
Anthropic created frontend-design, a skill that guides Claude toward better UI design. Impeccable builds on that foundation with deeper expertise and more control.
Every LLM learned from the same generic templates. Without guidance, you get the same predictable mistakes: Inter font, purple gradients, cards nested in cards, gray text on colored backgrounds.
Impeccable fights that bias with:
- An expanded skill with 7 domain-specific reference files (view source)
- 23 commands to audit, review, polish, distill, animate, and more
- Curated anti-patterns that explicitly tell the AI what NOT to do
What's Included
The Skill: impeccable
A comprehensive design skill with 7 domain-specific references (view skill):
| Reference | Covers |
|---|---|
| typography | Type systems, font pairing, modular scales, OpenType |
| color-and-contrast | OKLCH, tinted neutrals, dark mode, accessibility |
| spatial-design | Spacing systems, grids, visual hierarchy |
| motion-design | Easing curves, staggering, reduced motion |
| interaction-design | Forms, focus states, loading patterns |
| responsive-design | Mobile-first, fluid design, container queries |
| ux-writing | Button labels, error messages, empty states |
23 Commands
All commands are accessed through /impeccable:
| Command | What it does |
|---|---|
/impeccable craft |
Full shape-then-build flow with visual iteration |
/impeccable teach |
One-time setup: gather design context, write PRODUCT.md and DESIGN.md |
/impeccable document |
Generate DESIGN.md from existing project code |
/impeccable extract |
Pull reusable components and tokens into the design system |
/impeccable shape |
Plan UX/UI before writing code |
/impeccable critique |
UX design review: hierarchy, clarity, emotional resonance |
/impeccable audit |
Run technical quality checks (a11y, performance, responsive) |
/impeccable polish |
Final pass, design system alignment, and shipping readiness |
/impeccable bolder |
Amplify boring designs |
/impeccable quieter |
Tone down overly bold designs |
/impeccable distill |
Strip to essence |
/impeccable harden |
Error handling, i18n, text overflow, edge cases |
/impeccable onboard |
First-run flows, empty states, activation paths |
/impeccable animate |
Add purposeful motion |
/impeccable colorize |
Introduce strategic color |
/impeccable typeset |
Fix font choices, hierarchy, sizing |
/impeccable layout |
Fix layout, spacing, visual rhythm |
/impeccable delight |
Add moments of joy |
/impeccable overdrive |
Add technically extraordinary effects |
/impeccable clarify |
Improve unclear UX copy |
/impeccable adapt |
Adapt for different devices |
/impeccable optimize |
Performance improvements |
/impeccable live |
Visual variant mode: iterate on elements in the browser |
Use /impeccable pin <command> to create standalone shortcuts (e.g., pin audit creates /audit).
Usage Examples
/impeccable audit blog # Audit blog hub + post pages
/impeccable critique landing # UX design review
/impeccable polish settings # Final pass before shipping
/impeccable harden checkout # Add error handling + edge cases
Or use /impeccable directly with a description:
/impeccable redo this hero section
Anti-Patterns
The skill includes explicit guidance on what to avoid:
- Don't use overused fonts (Arial, Inter, system defaults)
- Don't use gray text on colored backgrounds
- Don't use pure black/gray (always tint)
- Don't wrap everything in cards or nest cards inside cards
- Don't use bounce/elastic easing (feels dated)
See It In Action
Visit impeccable.style to see before/after case studies of real projects transformed with Impeccable commands.
Installation
Option 1: Download from Website (Recommended)
Visit impeccable.style, download the ZIP for your tool, and extract to your project.
Option 2: Copy from Repository
Cursor:
cp -r dist/cursor/.cursor your-project/
Note: Cursor skills require setup:
- Switch to Nightly channel in Cursor Settings → Beta
- Enable Agent Skills in Cursor Settings → Rules
Claude Code:
# Project-specific
cp -r dist/claude-code/.claude your-project/
# Or global (applies to all projects)
cp -r dist/claude-code/.claude/* ~/.claude/
OpenCode:
cp -r dist/opencode/.opencode your-project/
Pi:
cp -r dist/pi/.pi your-project/
Gemini CLI:
cp -r dist/gemini/.gemini your-project/
Note: Gemini CLI skills require setup:
- Install preview version:
npm i -g @google/gemini-cli@preview- Run
/settingsand enable "Skills"- Run
/skills listto verify installation
Codex CLI:
# Project-local
cp -r dist/agents/.agents your-project/
# Or user-wide
mkdir -p ~/.agents/skills
cp -r dist/agents/.agents/skills/* ~/.agents/skills/
GitHub Copilot:
cp -r dist/github/.github your-project/
Trae:
# Trae China (domestic version)
cp -r dist/trae/.trae-cn/skills/* ~/.trae-cn/skills/
# Trae International
cp -r dist/trae/.trae/skills/* ~/.trae/skills/
Note: Trae has two versions with different config directories:
- Trae China:
~/.trae-cn/skills/- Trae International:
~/.trae/skills/After copying, restart Trae IDE to activate the skills.
Rovo Dev:
# Project-specific
cp -r dist/rovo-dev/.rovodev your-project/
# Or global (applies to all projects)
cp -r dist/rovo-dev/.rovodev/skills/* ~/.rovodev/skills/
Usage
Once installed, use commands in your AI harness:
/audit # Find issues
/normalize # Fix inconsistencies
/polish # Final cleanup
/distill # Remove complexity
Most commands accept an optional argument to focus on a specific area:
/audit header
/polish checkout-form
Note: Codex uses skills here, not /prompts: commands. Open /skills or type $impeccable. Repo-local installs live in .agents/skills/; user-wide installs live in ~/.agents/skills/. GitHub Copilot uses .github/skills/. Restart the tool if a newly installed skill does not appear.
CLI
Impeccable includes a standalone CLI for detecting anti-patterns without an AI harness:
npx impeccable detect src/ # scan a directory
npx impeccable detect index.html # scan an HTML file
npx impeccable detect https://example.com # scan a URL (Puppeteer)
npx impeccable detect --fast --json . # regex-only, JSON output
The detector catches 24 issues across AI slop (side-tab borders, purple gradients, bounce easing, dark glows) and general design quality (line length, cramped padding, small touch targets, skipped headings, and more).
Supported Tools
Contributing
See DEVELOP.md for contributor guidelines and build instructions.
License
Apache 2.0. See LICENSE.
The impeccable skill builds on Anthropic's original frontend-design skill. See NOTICE.md for attribution.
Created by Paul Bakaus