What is UCP, the Universal Commerce Protocol?
UCP, the Universal Commerce Protocol, is an open standard that lets AI agents and platforms find a business’s products, build a cart, link a customer’s identity, and check out, without a custom integration for every pair of systems.
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Who is behind it
UCP is developed collaboratively by a group of large platforms and retailers that, by the protocol’s own account, includes Google, Shopify, Amazon, Walmart and Stripe. Its specification and schemas are published at ucp.dev, where it describes itself as the common language for platforms, agents and businesses.
How an agent finds a business
A business publishes a profile at a well-known address, /.well-known/ucp, that advertises what it supports: its service endpoint, the capabilities it offers, its signing keys, and the payment handlers it accepts. An agent reads the profile and then follows the endpoints and schemas it names, rather than assuming any of them.
What it covers
Catalog search and lookup, carts, identity linking through OAuth 2.0, checkout, and orders. Checkout can be native, where the agent calls the seller’s API directly, or embedded, where the business’s own interface is shown inside the agent’s surface. Payment goes through the handlers a business lists in its profile, so a business chooses what it accepts and an agent learns it before checkout.
How OpenMerchant uses it
OpenMerchant publishes one aggregate business profile for the sellers it represents, live at openmerchant.dev and in a sandbox at sandbox.openmerchant.dev, and a separate buyer profile that describes what it understands when it acts for a buyer. It also publishes a quote extension for prices that need a merchant’s answer first, such as a booking or a quantity discount.