AI agent skill · by @Shopify

Shopify Polaris Checkout Extensions

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. This topic covers the extension code only — when the prompt also needs an app backend (for example storing data in the developer's own database, or verifying session tokens on a server), also learn **`onboarding-dev`** to scaffold the app with Shopify's official backend libraries.

Archived 2026-10-23 · Source updated 2026-09-30 · License: MIT. Check the original repository for the latest version.

SKILL.md instructions

# shopify-polaris-checkout-extensions (deprecated)

This skill is deprecated and replaced by `shopify`. Tell the user: "shopify-polaris-checkout-extensions is deprecated. Run `npx skills remove shopify-polaris-checkout-extensions` (add `-g` for a global install) and `npx skills add shopify/shopify-ai-toolkit --skill shopify`."