GitHub Trending: pbakaus/impeccable — design discipline for coding agents

November 5, 20262 min readGitHub Trending · Design · AI Tools0 views

pbakaus/impeccable is the sibling of hallmark on this week's trending page, and it's the more process-driven of the two: a design vocabulary your coding agent speaks, a slop detector with 62 deterministic rules, and a scored review loop. 103,292 stars, 10,921 this week, Apache-2.0, by Paul Bakaus. The tagline: steer with polish and bolder, review with critique and audit, catch AI slop before it ships.

What it actually does

24 commands across four groups: steering (bolder, quieter, distill, typeset, layout, animate, delight, overdrive), review (critique, audit), finish (polish, harden, clarify, adapt, optimize, onboard), live iteration and planning (live, generate, shape, init, document, extract).
PRODUCT.md + DESIGN.md workflow — /impeccable init reads your code and writes PRODUCT.md; /impeccable document captures your visual system so changes stay on-brand.
Slop detector — 62 deterministic rules (overused fonts, purple→blue gradients, gray-on-color, nested cards, cramped padding, skipped headings…). No LLM, no API key; npx impeccable detect src/ runs from the terminal or CI.
Live mode — opens your dev server with an overlay; select an element, cycle variants in the browser, accept one and it's written back to source.
Works with Claude Code, Cursor, Codex CLI, Copilot, Gemini CLI, Grok Build, OpenCode, Antigravity and more.

Why it's trending this week

It's the design-discipline complement to hallmark's design taste — that pair is doing for 'agent-built UI' what linters did for 'agent-written JS'. If your agent ships UI, this is the layer that makes the difference between 'passable' and 'considered'. Also, the CLI is genuinely usable in CI, which makes it more than a demo.

Who it's for

Teams whose agents ship UI and want a repeatable critique/audit step before merge.
Design engineers who want 'make it pop' to actually mean something to an agent.
Anyone hardening an agent-built surface: errors, i18n, overflow, edge cases (harden), or an accessibility and performance pass (audit).

What to check

Install: npx impeccable install, then /impeccable init once per project — decide if you want a build path with or without image generation.
The detector's pattern rules run on JSX/TSX; rendered-page rules (contrast, tiny text) need npx impeccable detect http://localhost:5173 pointed at your dev server.
Live mode edits your local checkout only — never wire it into a deployed site or weaken a production CSP to enable it.
Apache-2.0, free, actively developed — from the same author as the frontend-design skill lineage at Anthropic.

If hallmark teaches your agent taste, impeccable teaches it what judgment to apply. Heavyweight complements, both worth a real try. Repository: github.com/pbakaus/impeccable.

Written by

Shihab Hossain — Full-Stack Developer

I build fast, thoughtful products end-to-end — web experiences with React & Next.js, Android apps with Flutter, and the infrastructure behind them.

Work with me

All notes

What it actually does

24 commands across four groups: steering (bolder, quieter, distill, typeset, layout, animate, delight, overdrive), review (critique, audit), finish (polish, harden, clarify, adapt, optimize, onboard), live iteration and planning (live, generate, shape, init, document, extract).

PRODUCT.md + DESIGN.md workflow — /impeccable init reads your code and writes PRODUCT.md; /impeccable document captures your visual system so changes stay on-brand.

Slop detector — 62 deterministic rules (overused fonts, purple→blue gradients, gray-on-color, nested cards, cramped padding, skipped headings…). No LLM, no API key; npx impeccable detect src/ runs from the terminal or CI.

Live mode — opens your dev server with an overlay; select an element, cycle variants in the browser, accept one and it's written back to source.

Works with Claude Code, Cursor, Codex CLI, Copilot, Gemini CLI, Grok Build, OpenCode, Antigravity and more.

Why it's trending this week

What to check

Install: npx impeccable install, then /impeccable init once per project — decide if you want a build path with or without image generation.

The detector's pattern rules run on JSX/TSX; rendered-page rules (contrast, tiny text) need npx impeccable detect http://localhost:5173 pointed at your dev server.

Live mode edits your local checkout only — never wire it into a deployed site or weaken a production CSP to enable it.

Apache-2.0, free, actively developed — from the same author as the frontend-design skill lineage at Anthropic.

If hallmark teaches your agent taste, impeccable teaches it what judgment to apply. Heavyweight complements, both worth a real try. Repository: github.com/pbakaus/impeccable.