Checkout UI extensions overview

Checkout UI extensions let app developers build custom functionality that merchants can install at defined points in the checkout flow.

Shopify provides different types of extension points, APIs, and components to extend checkout and build custom functionality. For example, app developers can create extensions for custom fields and product offers that render directly in the checkout flow.

The relationships between key components and APIs in the checkout UI extensions

Extension points adapt when checkout flows adapt, like between guest checkout and Shop Pay.

Checkout UI extension points adapting for guest checkout and ShopPay