Impeccable

Impeccable is a free open-source design skill that gives coding agents 24 design commands and a 62-rule checker for AI-looking interfaces.

What it is: a shared design vocabulary for you and your agent

The repo is by Paul Bakaus, Apache 2.0 licensed, with a site at impeccable.style. The README's idea is that "make it pop" leaves an agent to guess, while /impeccable bolder the pricing cards loads a playbook written for that one move and aims it at one target. It says Impeccable is strongest on interfaces that already exist, and that building new pages is a harder mode it also supports.

• Steer:bolder, quieter, distill, colorize, typeset, layout, animate, delight and overdrive, which goes for shaders, spring physics and scroll-driven effects.
• Review:critique scores a design against usability heuristics and ranks what to fix first. audit checks accessibility, performance, theming and responsive behavior, with findings from P0 (blocking) to P3 (polish).
• Finish and plan:polish, harden for errors, i18n and edge cases, clarify for unclear copy, adapt, optimize, onboard, shape to plan the UX before code, and extract to pull repeated patterns into a design system.
• Context files: run /impeccable init once per project. It reads your code, asks only what it cannot infer, and writes PRODUCT.md. /impeccable document captures your existing visual system in DESIGN.md. Every later command reads both.

The checker, and three ways to run it

The detector has 62 deterministic rules for AI-generated UI tells, accessibility violations and quality problems such as cramped padding and skipped headings. The README says it uses no LLM and no API key, and scans HTML, CSS, JSX, TSX, Vue and Svelte. Source files get the pattern rules only. Rules that need a rendered page, such as low contrast and tiny text, run when you scan a URL.

• In your agent: a design hook scans every UI file the agent edits and hands the findings back before it calls the work done. It is offered on Claude Code, Cursor, Codex, GitHub Copilot, Grok Build and Hermes Agent. Codex, Grok Build and Hermes Agent need one more approval step before it runs.
• In CI or a terminal:npx impeccable detect src/, or a URL, with --json and --github output for Actions annotations. Exit code 2 means findings and 1 means a target could not be scanned.
• In your browser: a Chrome extension overlays the same findings on any live page.

Live mode, and the part to read first

/impeccable live opens your running dev server with an overlay. You select an element, pick a direction, and it swaps variants in place, then writes the one you accept back to your source. The README names Vite, Next, SvelteKit, Astro, Nuxt and plain HTML. It says live mode edits a local checkout only, and not to inject it into a deployed site or loosen a production CSP.

• The README warns that applying copy edits runs an optional impeccable:manual-edit-validate script from your package.json with your permissions, so review it in an unfamiliar repo.
• It also says that if no chat agent has polled in the last minute, Apply falls back to the codex CLI, or claude if codex is missing, with approvals, permission checks and sandboxing turned off and your environment inherited. Setting IMPECCABLE_LIVE_COPY_AGENT=chat keeps Apply in your chat session, and off disables it.

Install and requirements

• From your project root run npx impeccable install. It finds your coding tools, asks whether to install for the project or globally, and offers the hook. Then reload your tool and run /impeccable init, or $impeccable init on Codex. npx impeccable update refreshes it.
• The README lists Claude Code, Cursor, Codex CLI, GitHub Copilot, Devin, Replit Agent, Gemini CLI, Grok Build, OpenCode, Google Antigravity, Kiro, Trae, Rovo Dev, Qoder, Mistral Vibe, Pi, Hermes Agent, DeepSeek Harness and Veto.
• There are also a Claude Code marketplace install, a VS Code extension for Copilot that installs the skill without the hook, a git submodule route for a pinned team version, and a manual copy with no Node needed. A manual copy skips the hook and subagents. Node is only needed for npx, and the engine is a binary that ships with it or downloads once.

What the author says, and what it does not do

• Bakaus wrote on July 2, 2026 that he launched Renaissance Geek, the company behind Impeccable, with backing from a16z, and a partnership with GitHub under which Impeccable comes pre-bundled with the new GitHub Copilot app. He also wrote that it had passed 40,000 GitHub stars and 160,000 installs through skills.sh alone. These are the author's statements, not checked by Seailife.
• The same post says the absence of slop does not produce taste, that today's fix for slop becomes tomorrow's slop, and that the tool is meant to amplify the human's intent, not replace it. So the checker catches common tells, such as weak hierarchy and broken contrast, and does not judge whether a design is good.

How fresh it is

• This is not a new project. The repository was created on November 16, 2025. The skill is at v4.8.0, from October 26, 2026, and the engine had a v0.1.19 release on November 7, the day Seailife checked.
• On November 7 it had about 105,000 stars, about 6,200 forks and 71 open issues and pull requests together.
• Seailife did not install it or run a command, scan or live session. The commands, rules and warnings above are from the README and the author's post.