● Impeccable vs frontend-design It is an enriched fork of Anthropic’s frontend-design. What it adds: Advantages over frontend-design - 7 domain references always loaded: typography, color/contrast (OKLCH), spatial, motion, interaction, responsive, UX writing — frontend-design has more generic guidance. - 23 verbal commands (/polish, /audit, /critique, /distill, /bolder, /quieter, /harden, /animate, /typeset, /layout, /overdrive, /live, etc.) — a shared vocabulary for iteration, not just “build me a page.” - Deterministic detector: CLI + extension with 27 anti-pattern rules + 12 LLM-based critiques. Runs with npx impeccable detect src/ without an API key, and catches “AI slop” such as purple-to-blue gradients, Inter everywhere, card-inside-card, bounce easing, dark glows, long lines, cramped padding, small touch targets, and skipped heading levels. - Brand-vs-product register that adjusts defaults based on context. - /teach command that generates PRODUCT.md + DESIGN.md at the project root as a living design system. - /extract pulls reusable tokens/components into the design system. - Apache 2.0, multi-harness support: Claude Code, Cursor, Codex, Copilot, Gemini, etc. Where frontend-design still wins: it is already in your local Anthropic kit, with no extra installation; it is sufficient for “one-shot” UI work without needing an iteration vocabulary. Usefulness in Open Design OD is literally a platform that generates UIs via skills + design systems. Impeccable fits in three places: 1. OD design systems (apps/daemon serves design systems). Impeccable’s 7 references — OKLCH, motion curves, spatial, etc. — are exactly the kind of curated content OD distributes as a design system for agents. The 7 refs could be absorbed as an embedded “impeccable” design system. 2. OD skills protocol (docs/skills-protocol.md). The 23 commands become skills in the OD catalog — polish, critique, harden, and distill are iteration verbs missing from the current OD, which is more focused on generating from scratch. 3. Deterministic detector as a guardrail. The impeccable detect CLI can run as a post-generation lint step on artifacts saved by the daemon in .od/artifacts/ — closing the loop: “agent generated → does it have AI slop? → re-polish.” No API key, no cost.