* skill: drop quality tiers, keep the real brand-craft guardrails Codex's craft/brand pass introduced fast/ship/showpiece "quality bars" plus brand-specific build gates, asset ledgers, sub-agent review, and self-graded fallback labels. In practice those tiers became escape hatches rather than craft pressure: the final output should always be 10/10, and the real decision points are splashiness and maximalism, not quality. Removed: - All quality-bar / showpiece / fast / ship framing in shape.md and craft.md - Standalone Brand Direction (#4) and Asset Requirements (#10) sections in shape's brief; renumbered back to 1-10 - The Brand hard rules section in brand.md (folded its real prohibitions into the existing Imagery and Brand bans sections) - Brand-specific build-gate item, mock-fidelity bullet, production-bar bullet, present-step bullet in craft.md - Asset ledger ceremony in craft Step 4 - Review-only sub-agents and "self-reviewed fallback, not independently validated" machinery in craft.md and polish.md - The For brand surfaces, assess hard failures subsection in polish.md and the brand checklist row - tests/brand-showpiece-reference.test.mjs (and its package.json wiring) Kept (the real nuggets): - Asset-substitution prohibition: image-led briefs ship real/generated assets or canvas/SVG/WebGL, not generic CSS panels, cards, bullets, or copy - Repeated tiny uppercase tracked kicker labels as a brand ban - Detector/QA output is defect evidence only, never proof of quality - "What visual assets are real content here?" discovery question - Inspect each major section individually for brand and long-form work - repeated-section-kickers detection rule + fixture - CLI improvements (JSON to stdout, -json/-fast aliases, severity field) - critique.md: npx impeccable detect --json fix Harness output dirs refreshed via bun run build. Full test suite (186) passes. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * skill: strip gate ceremony; require shape pause; allow compact briefs The setup gate table and IMPECCABLE_PREFLIGHT banner pushed every craft run through ritual restatement (PRODUCT.md → original prompt → round 1 → round 2 → 70-line "confirmed brief" → critique → summary, all saying the same thing). Replaced with imperative prose that still demands the same work but skips the user-facing telemetry. Specifically: SKILL.md - Drop the Setup gate table and IMPECCABLE_PREFLIGHT banner. - Keep the imperative steps explicitly: load context, identify register and load brand.md or product.md, AND load the matching command reference (craft.md / shape.md / etc.) when a sub-command is invoked. The command-reference step is non-negotiable; without craft.md loaded the agent skips the shape-and-confirm pause. craft.md - Drop the Build Gate / Craft Contract formal sections; replace with one paragraph stating prerequisites. - Step 1 explicitly requires ending the response after presenting the shape output; the user must confirm before any code lands. Allows a compact 3-5 bullet brief when the prompt + PRODUCT.md already pin direction (full 10-section structure reserved for genuinely ambiguous tasks). - Step 3 image gate skips silently when image generation isn't natively available; no user-facing announcement. - Step 6 explicitly legitimizes "first pass clean, shipping" as a valid endpoint and bans inventing fake defects to demonstrate iteration. shape.md - Cap discovery at 1 round by default; second round only when first leaves material gaps. - Adds an "assert-then-confirm, not menu-with-escape" rule: when PRODUCT.md and the prompt make one option obvious, name it and ask for confirm or override instead of enumerating "Restrained / Committed / Or something else?" as a real choice. - Phase 2 brief has two forms now: compact (default for clear briefs) and full structured (genuinely ambiguous). Open Questions can't double as leading-with-Recommend; if you'd write "Recommend: X", decide X. - Image gate same as craft.md. Validated end-to-end with a Haiku skill-on observability run: agent loads craft.md plus the brief's recommended implementation refs, pauses for one productive question (accent color, trace fidelity, CTA), and ships an artifact with zero side-tab violations vs. the original v1 baseline. Cost trades up modestly for that quality. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * craft.md Step 6: Reading the screenshot is the inspection, not taking it A v4 eval run took 4 targeted screenshots (hero, mobile, tablet, query-section) and then never Read any of them back. The agent treated browser_screenshot itself as "I inspected" and shipped without the multimodal feedback loop ever closing. Detector caught the resulting slop (5+ side-tab violations) on adjacent runs that did the same thing. Step 6 now spells out the pattern explicitly: take the screenshot, then Read the resulting PNG so its image content enters the conversation as multimodal input, then critique what you actually see in the image. With a check: "if your critique could have been written without looking at the image, you didn't look at the image." Validated with v5b: agent took 6 screenshots, Read all 6 back, and shipped with zero detector findings (vs the previous greenfield runs that hit 1-12 findings each). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * craft + brand: framework foundation, build-pipeline respect, image verification Three closely-linked additions surfaced by an eval-harness session investigating why the agent always shipped flat single-file HTML and zero imagery on greenfield brand briefs. 1. craft.md gains a new Step 0 "Project Foundation" before Shape. Detects existing framework / component library / icon set and uses what's there. Greenfield: ask the user via AskUserQuestion with sensible defaults framed by the brief (Astro for content/ brand sites, SvelteKit/Next/Nuxt for app surfaces, single index.html only for one-shot demos). Skipping the framework decision and writing flat HTML "to satisfy the spec" produces work that reads as a 2018 prototype regardless of visual quality. 2. craft.md Step 5 production bar gains two bullets: - Respect the build pipeline. Edit source files and run the project's `npm run build`; do not write to build/ / dist/ / .next/ directly with cat/heredoc/Bash redirects. Bypassing the pipeline skips asset hashing, image optimization, code splitting, and CSS extraction. - Verify external image URLs before referencing them. Use an image-search MCP, web-fetch tool, or browser if available; guessed photo IDs ship as broken-image placeholders. 3. brand.md "Imagery" section: - Generalizes the Unsplash URL guidance to "verify URLs before referencing them" with a hierarchy: image-search MCP > web-fetch > confidence-restricted manual selection > fewer photos. - Tightens the tech/dev-tool exception. Old line "zero imagery can be correct" gave models a permission slip. New framing keeps the underlying truth (typography + code + diagrams primarily carry voice) but raises the floor: imagery still earns its place when it serves the brief, and skipping it requires naming the typographic/diagrammatic move that's carrying the visual weight instead. "Zero imagery is the failure mode of laziness, not restraint." Eval-harness corpus that prompted this: 19/19 brand landing tasks shipped 0 images each, including ones where Opus had taste enough to break the dev-tool color default lane. The skill needs to teach both halves of the decision; the harness shouldn't have to nudge. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * detector: body-text-viewport-edge rule + OKLCH/var-resolution + anchor-inherit FP fixes New rule: body-text-viewport-edge flags body paragraphs that render flush against the left/right viewport edges (no container padding). Tested via the new tests/fixtures/antipatterns/body-text-viewport-edge.html fixture (3 flag cases, 5 pass cases) and the test in detect-antipatterns-browser. False-positive class fixes — all jsdom-mode only (real browsers resolve the cascade correctly so these gates stay inert there). Five related gaps that compounded into ~14× spurious contrast findings on Tailwind v4 pages with OKLCH color tokens: • OKLCH parser. jsdom returns the literal "oklch(...)" string from getComputedStyle; the detector now converts to sRGB via Björn Ottosson's matrices. Handles Tailwind v4's compact minified form "oklch(21.5%.02 50)" (no space after %). • var() resolution. resolveBackground + checkElementColors now accept the existing customPropMap and parse `var(--color-paper)` etc. as proper RGB via the new parseColorResolved helper. • bg-color before bg-image. The old order bailed on any gradient ancestor before checking for a solid background-color underneath, causing the body's decorative paper-grain gradient to be measured against instead of the page's actual `bg-paper` cream. • body/html-level gradient → white fallback. When the only opaque ancestor we can read is body/html with a gradient overlay (and jsdom can't decompose `background: var(--paper) gradient` to extract the solid color), return white instead of falling through to resolveGradientStops — which was picking up paper-grain noise colors and using them as the bg. • Anchor-inherit workaround for jsdom :link UA specificity. Tailwind v4's preflight declares `a { color: inherit }` (0,0,1). jsdom's UA stylesheet has `:link { color: blue }` at (0,1,1) and wins the cascade. Real Chrome wraps :link in :where() (0,0,0) so the page rule wins. When the page declares the inherit rule AND we see jsdom's default `rgb(0,0,238)` on an anchor, walk to the nearest non-anchor ancestor and use its color. • Alpha-fallback safety gate. When text has alpha<1 AND we couldn't find an opaque ancestor (effectiveBg null), skip the contrast finding. Covers any remaining FP class the deeper fixes miss. Verified end-to-end against an Opus iter-1 artifact on Tailwind v4 with 14 cream/cream FPs + 2 blue-link UA FPs before; 0 findings after, while the color.html fixture's 12 real low-contrast cases continue to flag (verified via direct detectHtml calls). cli/engine/detect-antipatterns-browser.js is the generated browser distribution — regenerated from .mjs via scripts/build-browser-detector.js (no manual edits to the generated file). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * craft.md: tighten verbose passages, de-codex Step 6, cut redundancies Cumulative reduction: 218 → 155 lines (-29%). Step 0: drop the "Why this matters" paragraph at the end. The body of Step 0 already makes the framework-pick point; the paragraph just re-explains it with extra rhetoric. Step 1: replace the 4-sentence "you must end your response" block with a single line. The original said the same thing three different ways. Step 3: trim the conditional / defensive scaffolding (Purpose subsection, "do not skip because the eventual UI is semantic..." paragraph, duplicated approval-loop guidance). Mock fidelity inventory preserved. Step 4: drop the "keep UI text semantic" sentence; it duplicates Step 5's "Semantic first" rule. The rasterized-vs-semantic decision rule stays. Step 5: tighten each production-bar bullet to bold-lead + specifics format. All 15 rules preserved (real content, mock ingredients, semantic first, spacing/alignment, typography, state coverage, interaction quality, icon set, build pipeline, image URL verification, optimized imagery, premium motion, maintainability, technical cleanliness, ask-when-uncertain). Step 6: rewrite around "look at what you built like a designer would — your eyes are whatever the harness gives you." Drops Codex-specific "In Codex, use browser-use" bias. Drops the verbose 3-step Read pattern (condensed to one sentence). Drops the 1-8 numbered checklist (replaced by a tight paragraph). Keeps the load-bearing rules: read the PNG, don't fabricate iteration, mock fidelity reference, exit bar = studio defensibility. Step 7: drop the closing "Iterate based on feedback. Good design is rarely right on the first pass" preachy filler. All em-dashes converted to semicolons / colons / periods to satisfy the skill prose validator. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * build: native subagent pipeline + Codex-only asset producer Adds an agent cross-compile pipeline alongside the existing skill pipeline. Sources live at skill/agents/*.md; providers that declare agentFormat (codex-toml, claude-md) emit native subagent files. An optional providers: <list> field on an agent gates which harnesses get a copy; default (no field) ships everywhere. The impeccable-asset-producer agent is opt-in to Codex only. It's useful for Codex's native image generation path and is untested elsewhere; Claude has no native image gen anyway. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * brand: inverse-test + cultural-symbol palette guardrail Two additions to the brand register reference: - Inverse slop test: describe the page the way a competitor would describe theirs. If that sentence fits the modal landing page in the category, restart. - Palette guardrail: when a cultural-symbol palette is the obvious pull, reach past it. Let cultural reading come from typography, imagery, and copy. Harness mirrors regenerated; some also catch up to the image- verification paragraph frome3ad2efthat hadn't been re-synced. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * PRODUCT.md: widen audience beyond developers Designers, product managers, and engineers all use AI coding tools and want better design output. Keeping the audience narrow to "frontend and full-stack developers" understates who the skill is actually for. Also retitles "developer" to "user/builder" in the purpose statement. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * site + build: bump rule count to 29, strip changelog from detector check Two changes: - site/pages/index.astro: three live mentions of "28 rules / checks" bumped to 29 after the body-text-viewport-edge rule landed inb9bf496. - scripts/build.js: the detection-count validator was reading the unstripped content, so historical counts inside changelog entries (e.g. "28 rules" from an older release note) were flagging against the current detector total. The command-count check already strips the changelog ul; the detection check now does the same. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * test: align hero-eyebrow-chip fixture with relaxed rule gatesb9bf496intentionally relaxed two gates in checkHeroEyebrow: - removed the heading-size ≥ 48px anchor (modern hero h1s use clamp/vw/var that jsdom can't resolve) - raised the eyebrow text ceiling from 30 to 60 chars Two fixture cases that satisfied the negative side of the old gates now match the rule: - "Body-Sized Heading Below Eyebrow" — 24px h1 with tracked-caps label above. Per the rule's stated intent ("a tiny tan label directly above any h1 is the antipattern regardless of how big the h1 ends up"), this is a flag. - "Long Uppercase Sentence Above Hero" — 46-char tracked-caps label is under the new 60-char ceiling, so still eyebrow-shaped. Both cases moved from the should-pass column to should-flag, with case descriptions rewritten to explain the gate they exercise. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Paul Bakaus <paulbakaus@pauls-mbp-3.lan> Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
9.4 KiB
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's frontend-design was the first widely-used design skill for Claude. Impeccable started from there.
Every model trained on the same SaaS templates. Skip the guidance and you get the same handful of tells on every project: Inter for everything, purple-to-blue gradients, cards nested in cards, gray text on colored backgrounds, the rounded-square icon tile above every heading.
Impeccable adds:
- 7 domain reference files (view source). Typography, color, motion, spatial, interaction, responsive, UX writing. Load on every command, alongside a brand-vs-product register that adjusts the defaults.
- 23 commands. A shared design vocabulary with your AI:
polish,audit,critique,distill,animate,bolder,quieter, and more. - 27 deterministic anti-pattern rules plus a 12-rule LLM critique pass. CLI and browser extension run the deterministic ones with no LLM and no API key. Each is tied to specific design guidance the skill teaches against.
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 root PRODUCT.md and DESIGN.md |
/impeccable document |
Generate root 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/
mkdir -p your-project/.codex
cp -r dist/codex/.codex/agents your-project/.codex/
# Or user-wide
mkdir -p ~/.agents/skills
cp -r dist/agents/.agents/skills/* ~/.agents/skills/
mkdir -p ~/.codex
cp -r dist/codex/.codex/agents ~/.codex/
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/
Qoder:
# Project-specific
cp -r dist/qoder/.qoder your-project/
# Or global (applies to all projects)
cp -r dist/qoder/.qoder/skills/* ~/.qoder/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
Community & Ecosystem
Join the community and ecosystem conversations:
- GitHub Discussions: file bugs, request features, and help newcomers.
- Impeccable on npm: grab the CLI, follow releases, and star the package.
- Follow @pbakaus on Twitter for release notes, sample lint reports, and video highlights of new rules.
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