Paul BakausandClaude Fable 5
7a99e1725d
Four gaps found shipping in Opus 4.8 eval samples during human review: 1. low-contrast (extended): the browser adapters parsed text/own-bg colors with parseRgb only, so Chrome's oklch()-serialized computed colors silently skipped every contrast check — a flat dark-on-dark nav CTA (broader nav selector beating the button class) shipped at 1.5:1 undetected. checkElementColorsDOM and readOwnBackgroundColor now fall back to parseAnyColor. Near-threshold ratios print two decimals so a 4.497 finding no longer reads "4.5 needs 4.5". 2. NEW numbered-section-labels (slop, advisory): tiny (<=13px) styled numeric index labels riding beside section headings, repeated across 2+ sections with distinct indices. Sibling of repeated-section-kickers (which deliberately excludes bare numeric labels); handles both the direct prev-sibling shape and label-before-heading-wrapper shape. List/nav/table/card-item numbering is exempt. 3. side-tab (extended): the vertical pseudo-element stripe scan required the stripe to touch both corners (top/bottom 0 or height 100%), so a left accent bar inset a few px from each end evaded it; small end insets (<=20px each) now count. Added a browser-side pseudo-element check (getComputedStyle(el, '::before'/'::after')) since runtime- assigned custom-property colors are invisible to the text scanner. Selection-state exemptions stay as narrowed: only aria-selected=true / aria-current / active-class markers exempt, plus button/link affordances on the horizontal variant. 4. NEW repeated-container-text (quality): the same literal string (>=4 chars, contains letters) rendered 3+ times at 3+ structurally distinct positions inside one bordered/elevated container. Parallel/templated repetition (table cells, calendar grids, nav lists, identical sibling rows) never counts — structural signatures, not word lists. Verified: each rule fires on its repro sample via the file:// browser scan; clean eval samples add no new findings (the new low-contrast hits on other samples are genuine sub-AA oklch button pairs). Full test suite green; browser bundle regenerated; README/homepage rule counts bumped 49 -> 51 (docs-integrity test enforces them). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2.7 KiB
Impeccable CLI
Detect UI anti-patterns and design quality issues from the command line. Scans HTML, CSS, JSX, TSX, Vue, and Svelte files for 51 deterministic rules, including AI-generated UI tells, accessibility violations, and general design quality problems.
Quick Start
# Install skills into your AI harness (Claude, Cursor, Gemini, etc.)
npx impeccable skills install
# Non-interactive install for a specific scope
npx impeccable skills install -y --providers=claude,codex --scope=project
# First command to run inside your AI harness
/impeccable init
# Update skills to the latest version
npx impeccable skills update
# Install or update skills without hook manifests
npx impeccable skills install --no-hooks
# Link skills from a Git submodule checkout
npx impeccable skills link --source=.impeccable --providers=claude,cursor
# List all available commands
npx impeccable skills help
# Scan files or directories for anti-patterns
npx impeccable detect src/
# Scan a live URL (requires Puppeteer)
npx impeccable detect https://example.com
# JSON output for CI/tooling
npx impeccable detect --json src/
# Deprecated compatibility flag; full scan still runs
npx impeccable detect --fast src/
What It Detects
AI Slop Tells: patterns that scream "AI generated this":
- Side-tab accent borders, gradient text on headings
- Purple/violet gradients and cyan-on-dark palettes
- Dark mode with glowing accents, border + border-radius clashes
Typography Issues: overused fonts (Inter, Roboto), flat type hierarchy, single font families
Color & Contrast: WCAG AA violations, gray text on colored backgrounds, pure black/white
Layout & Composition: nested cards, monotonous spacing, everything-centered layouts
Motion: bounce/elastic easing, layout property transitions
Quality: tiny body text, cramped padding, long line lengths, small touch targets
51 deterministic detector rules in total. See the full catalog at impeccable.style/slop.
Exit Codes
0: no issues found2: anti-patterns detected
Options
impeccable detect [options] [file-or-dir-or-url...]
--fast Regex-only mode (skip jsdom, faster but less accurate)
--json Output findings as JSON
--help Show help
Requirements
- Node.js 22.12+
jsdom(included as dependency, used for HTML scanning)puppeteer(optional, only needed for URL scanning)
Part of Impeccable
This CLI is part of Impeccable, a cross-provider design skill pack for AI-powered development tools. The full suite includes 23 commands for Claude, Cursor, GitHub Copilot, Gemini, Codex, and more.