How do I install Impeccable?
It is a Claude skill. One command.
Step 1: Install via the skill registry
bash
npx skills add pbakaus/impeccable
The official repo is github.com/pbakaus/impeccable.
Step 2: Verify the slash commands are available
In Claude Code, type / and you should see new commands:
/polish— refine an existing component/typeset— fix typography hierarchy/arrange— fix spatial relationships/bolder— push the design louder/quieter— pull the design back/overdrive— go full art-direction
Step 3: Use it on your existing UI
Open any component file in Claude Code. Run:
/typeset
Claude reads the component, applies the typography reference file, and rewrites the type scale to match production standards. As of v1.5.1 (March 17, 2026), /typeset recommends fixed type scales for app UIs and reserves fluid typography for marketing pages.
Step 4: Layer multiple commands
The real power is composition:
/typeset
/arrange
/polish
That sequence: fixes type, then fixes spacing, then polishes everything. The output looks like a senior designer wrote it.
Step 5: Use it in Cursor, Copilot, or Codex CLI
Impeccable is harness-agnostic. The README emphasizes it works in Claude Code, Cursor, Gemini CLI, Codex CLI, Copilot, and Kiro. One install, every editor.
What is Impeccable?
Impeccable is an open-source design skill layer for AI coding tools. It is not a component library, not a CSS theme, not a design system. The maintainer's own framing: "a vocabulary layer that sits between your intent and the AI's execution."
The repo crossed 10,000 GitHub stars and was built by Paul Bakaus, a former Google engineer and creator of Khroma. The skill ships seven domain-specific reference files: typography, color and contrast (OKLCH), spatial design, motion design, interaction design, responsive design, and UX writing.
Is Impeccable really free?
Yes — MIT licensed, free forever. There is no SaaS, no subscription, no account required. You install it as a Claude skill and it lives on your local machine. The repo description is direct: "The design language that makes your AI harness better at design."
How is Impeccable different from a design system or component library?
Three differences:
- It teaches the model, not you. A design system is documentation for humans. Impeccable is a vocabulary layer the AI reads at generation time.
- It is harness-agnostic. Works in Claude Code, Cursor, Gemini CLI, Codex CLI, Copilot, and Kiro. One install, every editor.
- It composes.
/typesetthen/arrangethen/polishchains naturally. Component libraries do not chain — you import them and write CSS yourself.
What you get: AI output that no longer reads as AI. Better type scales, intentional whitespace, considered color choices, and motion that feels designed instead of bolted on.
What's the catch?
- It needs a capable underlying model. Impeccable amplifies Claude or GPT-class models. On weaker models, the gain is smaller because the model cannot follow the vocabulary.
- It is not a Figma replacement. If you need pixel-perfect mocks before you write code, you still want a design tool. Impeccable kicks in at the implementation step.
- The slash commands assume a Claude-skill-aware harness. Most modern coding tools support this — but if yours does not yet, you fall back to copy-pasting the reference files into your prompt context.
Bottom line
Impeccable is the cheapest 10x design upgrade you can install. One npx command, free forever, works in every AI coding harness. If your AI-generated UI looks like AI-generated UI, this fixes it in an afternoon.
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