Use when domain values are raw strings or numbers, when the same format or range check appears in more than one place, or when ids can be swapped.
Install
npx skills add yutna/functional-design-skills --skill functional-constraining-primitive-valuesnpx skills add yutna/functional-design-skills --skill functional-constraining-primitive-values -a claude-code -gnpx skills add yutna/functional-design-skills --skill functional-constraining-primitive-values -a codex -ggemini skills install https://github.com/yutna/functional-design-skills.git --path plugin/skills/functional-constraining-primitive-valuesgh skill install yutna/functional-design-skills functional-constraining-primitive-valuesgit clone --depth 1 https://github.com/yutna/functional-design-skills /tmp/yutna__functional-design-skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/yutna__functional-design-skills/plugin/skills/functional-constraining-primitive-values ~/.claude/skills/functional-constraining-primitive-values # Claude Code
cp -R /tmp/yutna__functional-design-skills/plugin/skills/functional-constraining-primitive-values ~/.agents/skills/functional-constraining-primitive-values # Codex, Cursor, Gemini CLI, Copilot, OpenCode