Impeccable.

Definition

Impeccable is an open-source tool created by Paul Bakaus that provides a shared design vocabulary between the programmer and AI agents. Its motto is «the missing design vocabulary for agents» and its goal is to avoid the generic look of AI-generated code (what it calls «AI slop») by relying on design principles such as hierarchy, contrast, and containment. It includes 23 design commands mapped to disciplines (for example /typeset, /colorize, /animate), integration with the existing design system that inherits tokens and components instead of overwriting them, portable DESIGN.md documentation, a «slop» detector with 46 deterministic rules for PR reviews, and builds tuned per model (Codex, Gemini, Claude). It is installed from the Claude Code marketplace, npm, and as a Chrome extension.