How to write an AI skill to disk so it is portable to any AI and auto-triggers in Claude — the two-file convention (thin SKILL.md adapter + a named <skill>.md guide that holds all the real content), the adapter template and footers, trigger-rich descriptions with the /slash command, sibling references instead of absolute paths, scripts shipped alongside, the base+overlay and family patterns…
Install
npx skills add flywheel-product/ai-build-skills --skill skillwriternpx skills add flywheel-product/ai-build-skills --skill skillwriter -a claude-code -gnpx skills add flywheel-product/ai-build-skills --skill skillwriter -a codex -ggemini skills install https://github.com/flywheel-product/ai-build-skills.git --path skillwritergh skill install flywheel-product/ai-build-skills skillwritergit clone --depth 1 https://github.com/flywheel-product/ai-build-skills /tmp/flywheel-product__ai-build-skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/flywheel-product__ai-build-skills/skillwriter ~/.claude/skills/skillwriter # Claude Code
cp -R /tmp/flywheel-product__ai-build-skills/skillwriter ~/.agents/skills/skillwriter # Codex, Cursor, Gemini CLI, Copilot, OpenCode