UCP Payment Handlers

Before writing code

Fetch live docs:

• Google Pay handler: https://developers.google.com/merchant/ucp/guides/google-pay-payment-handler
• Shop Pay handler: Web-search site:shopify.dev UCP Shop Pay payment handler
• Payment architecture: https://ucp.dev/specification/overview/ (payment section)
• Reference types: https://ucp.dev/specification/reference/ (credential and instrument schemas)

Conceptual Architecture

Trust Triangle

Business <——> PSP <——> Credential Provider