Impeccable is an open-source design skill for AI coding agents created by Paul Bakaus and released under the Apache License 2.0. It started from Anthropic's frontend-design skill and targets the patterns that make AI-generated interfaces look alike, such as default fonts, purple-to-blue gradients, nested cards and gray text on colored backgrounds. The project also ships a self-contained engine, a CLI and a browser extension; its GitHub repository had about 86,600 stars on October 25, 2026.
Everything runs through one /impeccable command with 24 sub-commands, including init, audit, critique, polish, distill, harden, animate and live. init inspects the project and records durable product context in PRODUCT.md, and visual decisions for an existing design system are kept separately in DESIGN.md. live and generate iterate on elements as variants in the browser, and pin creates standalone shortcuts such as /audit.
A deterministic detector with 62 rules checks rendered pages for AI-generated design patterns; it runs from the CLI (npx impeccable detect) or the browser extension without an LLM or API key, while LLM-only critique checks run inside the agent. Installation is npx impeccable install, which detects harness folders for Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Grok Build, Hermes and others and can add provider-native hooks; it can also be vendored as a git submodule, added from the Claude Code plugin marketplace or installed as a VS Code extension.
Impeccable is free. When a new design starts, the skill calls a roll API at impeccable.style to deal visual directions; that request always happens. Unless you opt out, it also records an anonymous record of which option was shown and which one was chosen; project names, files, code and PRODUCT.md are not sent. Telemetry can be turned off with npx impeccable telemetry off, DO_NOT_TRACK=1 or IMPECCABLE_NO_TELEMETRY=1, or for a whole project in .impeccable/config.json.
