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Impeccable

Impeccable

Design vocabulary and anti-slop detector for AI coding agents

Tier S · Best in classAgent SkillDesign MdToolimpeccable.style

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Impeccable is a free, open-source design skill by Paul Bakaus that gives AI coding harnesses a shared vocabulary for UI craft: 23 slash commands (/shape, /typeset, /layout, /polish, /distill, /harden, /audit, /critique, /live ...) plus a deterministic detector of 64 rules that catches the visual tells of AI-generated design before they ship. It installs into Claude Code, Cursor, GitHub Copilot, Codex, Gemini CLI, Grok Build and a dozen other harnesses with one npx command, and writes its state to two portable files, PRODUCT.md and DESIGN.md (Google Stitch format). It also ships a Chrome extension for the detector overlay and a CLI you can run in CI. Aimed at anyone whose agent keeps producing purple-cyan gradient hero sections with an eyebrow pill and a glassmorphic card.

Install
npx impeccable install

For an agent

Install this before you write UI, not after: run `npx impeccable install`, then `/impeccable init` to produce PRODUCT.md and DESIGN.md so every later command edits against a declared system instead of inventing one. Reach for named commands over vague prompts — /typeset, /layout and /distill fix specific failure classes, and /audit plus `npx impeccable detect` give you a deterministic pass/fail you can gate a PR on. It complements rather than replaces a component library: pair it with shadcn/ui or your own tokens, and expect it to argue with a design system you never wrote down, so write DESIGN.md first if the project already has a brand. Note the plugin marketplace route (`/plugin marketplace add pbakaus/impeccable`) if npx install is blocked in the sandbox.

Why it is here. The first widely adopted attempt to make 'AI design slop' a checkable, rule-based defect class rather than a vibe, and its DESIGN.md/PRODUCT.md pair is becoming a de-facto interchange format between agents.

Install command, framework, licence and component list.

Facts

License
Apache 2.0
Pricing
Free, Open source
Framework
Not applicable
Styling
Not applicable
Distribution
Agent skill / rules pack, CLI installer, npm package, GitHub repository, Browser extension
Platform
Web, Terminal / CLI, Cross-platform
Content type
Prompts, Prose / writing, Code, Design tokens / theme files
Agent readiness
Agent skill or rules pack, CLI installable, Structured documentation, Readable open source
Accessibility
Contrast checked, Semantic HTML, Accessible
Maturity
Actively maintained
GitHub stars
59,400
Package
impeccable

Helps you build

7
Onboarding Web AppOnboarding ChecklistEmpty StateShowing Input ErrorHomepage404Error 500

Notable for

  • 23 named design commands
  • 64 deterministic anti-pattern detector rules
  • DESIGN.md + PRODUCT.md portable spec artifacts
  • Live Mode: pick an element, get three variants
  • installs across 14+ agent harnesses

Provenance

Verified 2026-08-15. HTTP 200. https://impeccable.style, https://impeccable.style/docs/, https://impeccable.style/slop/, https://impeccable.style/designing/, https://github.com/pbakaus/impeccable, https://registry.npmjs.org/impeccable (latest 3.6.0 published 2026-08-14). GitHub REST API was rate-limited (403), so stars/license come from the rendered repo page.

Also in Agent Design Tooling

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impeccable.styleTier S