Build custom functionality that merchants can install at defined points in the checkout flow, including product information, shipping, payment, order summary, and Shop Pay. Checkout UI Extensions also supports scaffolding new checkout extensions using Shopify CLI commands.
Install
npx skills add openai/plugins --skill shopify-polaris-checkout-extensionsnpx skills add openai/plugins --skill shopify-polaris-checkout-extensions -a claude-code -gnpx skills add openai/plugins --skill shopify-polaris-checkout-extensions -a codex -ggemini skills install https://github.com/openai/plugins.git --path plugins/shopify/skills/shopify-polaris-checkout-extensionsgh skill install openai/plugins shopify-polaris-checkout-extensionsgit clone --depth 1 https://github.com/openai/plugins /tmp/openai__plugins
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/openai__plugins/plugins/shopify/skills/shopify-polaris-checkout-extensions ~/.claude/skills/shopify-polaris-checkout-extensions # Claude Code
cp -R /tmp/openai__plugins/plugins/shopify/skills/shopify-polaris-checkout-extensions ~/.agents/skills/shopify-polaris-checkout-extensions # Codex, Cursor, Gemini CLI, Copilot, OpenCode