Show HN: Pristine – an agent skill that critiques and polishes web UI

An agent skill that makes web UI pristine. It looks at the real page (light and dark, desktop and mobile), judges it through the eyes of the people who use your product, and either scores it honestly or fixes it.

Works with Claude Code, Codex, GitHub Copilot, Cursor and any agent that reads SKILL.md.

Site and examples: https://pristine-ui.pages.dev

Eight real before/after pairs, with the full critique and every change: https://pristine-ui.pages.dev/#examples

Command What it does Edits code

/pristine init Reads your code, asks only what it can't see, and writes DESIGN.md: product, Personas, brand, design system. yes

/pristine critique <target> Scores a page out of 10 across 11 Dimensions, through each Persona, with the exact fix for every finding. no

/pristine design <brief> Builds a new page, component or flow, or redesigns one in a new direction. yes

/pristine polish [lenses] <target> Keeps the look and raises every detail. The default for a bare /pristine on existing UI. yes

A target can be a URL, a pasted screenshot, a file path or a feature name. Name Lenses after polish to force them, for example /pristine polish bolder typeset the hero. There are 16: bolder, colorize, typeset, quieter, decolorize, distill, layout, adapt, consistency, animate, delight, overdrive, clarify, harden, optimize, polish-details.

Full reference with examples: https://pristine-ui.pages.dev/docs/

Claude Code

/plugin marketplace add maddhruv/pristine /plugin install pristine@pristine

Codex

codex plugin marketplace add maddhruv/pristine codex plugin add pristine@pristine

GitHub Copilot (CLI and VS Code)

copilot plugin marketplace add maddhruv/pristine copilot plugin install pristine@pristine

Any agent (skills.sh)

npx skills add maddhruv/pristine

By hand

git clone https://github.com/maddhruv/pristine ~/pristine ln -s ~/pristine/skills/pristine ~/.claude/skills/pristine # or ~/.copilot/skills, ~/.agents/skills

Then, in your project, run /pristine init once and /pristine on whatever you're building.

Pristine captures pages before it judges them. It uses a browser tool your agent already has (Claude in Chrome, an agent browser, Playwright MCP). If there is none, scripts/capture.mjs installs a private Playwright Chromium into ~/.cache/pristine-capture on first run. Node 18+ is required for the bundled scripts.

skills/pristine/ SKILL.md entry point: commands, routing, non-negotiables agents/openai.yaml display metadata for Codex reference/ one file per command, plus capture, craft floor reference/lenses/ the 16 Lenses reference/patterns/ landing pages, dashboards, onboarding, motion recipes, ... scripts/capture.mjs light/dark x desktop/mobile screenshots, zoom, element capture scripts/detect.mjs static scan for common UI defects site/ the showcase (Astro, Cloudflare Pages), built with Pristine .claude-plugin/ plugin and marketplace manifests

Contributing

See CONTRIBUTING.md and the Code of Conduct. Bug reports that include the session, the harness and the model are the most useful thing you can send.