Try to break a piece of UI by feeding it worst-case data — long names, unbreakable emails, one-letter names, missing fields, huge counts, zero items, long labels, non-Latin text, emoji, extreme numbers — then render it behind a "Demo data / Worst case" toggle and report everything that broke, with the fix for each.
Install
npx skills add emilkowalski/skills --skill break-uinpx skills add emilkowalski/skills --skill break-ui -a claude-code -gnpx skills add emilkowalski/skills --skill break-ui -a codex -ggemini skills install https://github.com/emilkowalski/skills.git --path skills/break-uigh skill install emilkowalski/skills break-uigit clone --depth 1 https://github.com/emilkowalski/skills /tmp/emilkowalski__skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/emilkowalski__skills/skills/break-ui ~/.claude/skills/break-ui # Claude Code
cp -R /tmp/emilkowalski__skills/skills/break-ui ~/.agents/skills/break-ui # Codex, Cursor, Gemini CLI, Copilot, OpenCode