What is UCP?
Universal Commerce Protocol, the checkout protocol that completes a purchase once an AI agent has already been connected, identified and authorised, handing a business back a confirmed order instead of an unverified promise.
2 min read
Everything else in the chain, connection, identity, spending authorisation, gets a purchase ready. UCP closes it: the business gets a confirmed transaction it can settle, rather than sending a customer off to finish the job on a website after the fact. It's the last of the four jobs an agent-completed purchase has to do.
Good for
Closing a purchase once everything else is already handled.
Not good for
Any of the steps before it, connection, identity and authorisation are separate protocols entirely.
What is MCP?
Model Context Protocol, an open standard that lets an AI agent call into a business's own systems, checking live data or triggering a defined action, the way it would check availability or pull a menu.
What is AP2?
Agent Payments Protocol, a standard for proving that a real person authorised an AI agent to spend a specific amount, so a business can verify that before it charges anything.
What is ACP?
Agentic Commerce Protocol, an open checkout standard, associated with OpenAI and Stripe, for an AI agent to complete a purchase directly inside a conversation rather than sending the shopper off to a separate website.