About the Cart and Checkout Validation Function API
The Validation API allows developers to provide their own validation of a cart and checkout, including express checkouts, such as PayPal, Shop Pay, Google Pay, and Apple Pay.
Example use cases
Anchor link to section titled "Example use cases"- Use tokengating or require a customer membership at checkout.
- Verify the age or ID of a customer when they proceed through checkout.
- Provide B2B product minimums, maximums, and multiples.
- Provide B2B location order minimums, maximums, or credit limits.
- Specify quantity limits in a flash sale.
Developer tools and resources
Anchor link to section titled "Developer tools and resources"Limitations and considerations
Anchor link to section titled "Limitations and considerations"- The Validation API doesn't currently support draft orders.
- Validation functions are cached. This can result in a delay (typically, less than one minute) between changes being made and those changes being live.
- Learn how to use Validation functions by validating a cart and checkout.