pbakaus/impeccable: The design language that makes your AI harness better at design.

The design language that makes your AI harness better at design. - pbakaus/impeccable

Summary

Impeccable is an Apache-2.0 design guidance package for AI coding agents, delivered as a single skill with 24 commands and 61 deterministic detector rules. It targets recurring anti-patterns in AI-generated frontend design and integrates with coding harnesses like Cursor, Claude Code, Codex, Gemini CLI, Grok Build, and Hermes, while also running as a standalone CLI without an LLM.

What it is useful for

The skill helps engineers who use AI assistants to build UIs and want a shared design vocabulary for their agent. It flags specific anti-patterns the README calls out: overused fonts (Arial, Inter, system defaults), gray text on colored backgrounds, pure black/gray without tint, cards nested in cards, and bounce/elastic easing. The 61 deterministic rules run in the CLI and browser extension with no API key, which makes them usable in scripted checks. Named commands target concrete jobs: audit for technical quality (a11y, performance, responsive), polish for shipping readiness, critique for UX review, harden for error handling and edge cases, distill for stripping to essentials, plus bolder, quieter, animate, typeset, layout, and delight.

How engineers can use it

The README documents this two-step quick start from the project root:

npx impeccable install
/impeccable init

install detects harness folders such as ~/.claude, ~/.codex, ~/.grok, or project-local .cursor and asks for project or global scope; --providers=claude,codex,cursor,grok,hermes,veto and --scope=project|global skip the prompts in scripts. After init writes PRODUCT.md, run targeted commands like /impeccable audit the header or /impeccable harden checkout, and pin shortcuts via /impeccable pin audit. The standalone CLI scans paths and live URLs: npx impeccable detect src/ or npx impeccable detect https://example.com, with --json for CI output and npx impeccable ignores add-value for managing detector exceptions. A companion browser extension runs the same rules.

Documented limitations to plan around: live mode is local only and explicitly not supported on deployed production sites, including HTTPS; the README warns against weakening production CSP to make it work. Codex users must open /hooks after install or update to approve the project hook. Grok Build requires /hooks-trust or --trust per folder. Hermes project-local installs need a one-time hermes skills trust. The VS Code extension needs VS Code 1.109.3+ and a trusted local workspace. The README also notes Claude Code hooks run independently of model-tool approval and recommends reviewing installed hooks before unattended runs.