About cart and checkout validation

Validation is the process of checking data against specified requirements. This guide introduces checkout validations and describes the available resources that you can use to build validations in Shopify checkout.

Anchor to How it worksHow it works

You can use Shopify Functions to create validations that ensure purchases meet certain criteria before a customer can check out or complete an order.

Validation functions run on Shopify's servers and can block checkout progress when business rules aren't met. For example, you can enforce order limits for new customers, prevent shipping to restricted locations, or ensure that loyalty program rules are properly applied.

Validation functions are available for online store carts, carts built for custom storefronts, and throughout the checkout process. They provide reliable enforcement of business logic that can't be bypassed by customers.

Anchor to Getting startedGetting started

Follow these tutorials to get started with building validations in checkout.

Create checkout validation

Use Shopify Functions to create validation rules that block completing an order when the cart doesn't meet certain criteria.

Create the admin UI

Use Shopify Functions to limit a cart's item quantity during checkout according to the merchant's preferences.

Anchor to Developer tools and resourcesDeveloper tools and resources

Explore the following developer tools and resources to get familiar with building validations in checkout.

Checkout UI extensions API reference

Consult the API reference for checkout UI targets and their respective types.

FunctionSettings component reference

Learn about the component that you can use to build a UI extension for your validation function.

Components for checkout UI extensions

See the full list of components that are available in checkout UI extensions.

Checkout extension configuration

Learn about the properties that you can configure in your checkout UI extension.

Cart and Checkout Validation Function API reference

Consult the GraphQL reference for the Cart and Checkout Validation Function API.

Language support

Learn about the language support and tooling that are available in Shopify Functions.