Impeccable

What it is

A free, Apache-2.0 design skill for AI coding agents. Per its README it is "1 skill, 24 commands": you run /impeccable <command> <target> inside your agent (commands like polish, critique, bolder and quieter) to give the agent a shared design vocabulary. It also ships a detector with 60 deterministic rules that flags tells of AI-made frontends, such as purple gradients, overused fonts, gray text on color and nested cards.

Setup

1. From your project's root folder, run the installer. It detects your agents and asks where to install. It needs Node.js 22.18 or newer.

   npx impeccable installCopy

2. Inside your AI coding tool, run the one-time setup. It writes a PRODUCT.md that records your audience, purpose and constraints.

   /impeccable initCopy

3. Claude Code plugin instead of the installer: add the marketplace, then open /plugin and install Impeccable from the list.

   /plugin marketplace add pbakaus/impeccableCopy

4. Use a command on a target, for example:

   /impeccable critique landingCopy

5. Scan code for the tells without any AI (works on a folder, an HTML file or a URL):

   npx impeccable detect src/Copy

6. Codex: after installing, open /hooks and approve the project hook when prompted.

Cheat sheet

• Repository and README and the official site.
• 24 commands, including init, critique, audit, polish, bolder, quieter, distill, typeset, layout and colorize. bolder amplifies boring designs; quieter tones down overly bold ones.
• The detector's 60 rules and "no LLM, no API key" come from the README. The website says 61 checks, so treat 60 as the README's number.
• The README's own warning: "A clean detector run is evidence, not proof of visual or accessibility quality." Review the result yourself.
• Works with the 17 tools in the README's Supported Tools list, including Claude Code, Cursor, Codex CLI, Gemini CLI and GitHub Copilot.
• On Claude Code, GitHub Copilot, Codex, Cursor and Grok Build, the installer also adds a hook that runs the detector when the agent edits UI files. On an interactive install it explains the hook and offers it (default yes); --no-hooks skips it.
• The first run downloads the engine binary (about 14 to 17 MB) into ~/.impeccable/bin/ unless it ships next to the launcher. Scanning a URL with npx impeccable detect needs Chrome, Chromium or Edge installed.
• Costs: the skill is free. Your agent's own usage applies.

Axo's take

AXO

Haven't run it myself: this page comes from the project's README. Try it if your agent's websites could swap logos and nobody would notice. If it comes out purple anyway, the README says it's evidence, not proof.