What is the Universal Commerce Protocol (UCP)?

By the Variask team · Updated

Definition

The Universal Commerce Protocol (UCP) is an open standard, announced by Google with Shopify and other partners in January 2026, that lets AI agents discover what a store supports and complete purchases with it in a common way.

Also called UCP

With Variask: The free Variask UCP readiness check looks for a UCP profile on your store and checks the product data agents rely on.

How UCP works

  • A store publishes a profile at /.well-known/ucp that declares its services, capabilities, endpoints and signing keys.
  • Checkout is the core capability, with extensions such as discounts and fulfillment.
  • Agents and stores agree on the capabilities both support.
  • It works over REST, the Model Context Protocol and Agent2Agent.
  • Payment authorization can use the Agent Payments Protocol (AP2).

What it means for brands

  • Stores on platforms that support UCP may get it through their platform; others need to publish the profile and endpoints themselves.
  • UCP does not replace good product data; agents still need accurate prices, stock and policies.

Questions

Universal Commerce Protocol (UCP):
common questions

No. Both standardize agent checkout. UCP is led by Google with commerce partners; the Agentic Commerce Protocol was created by OpenAI and Stripe for checkout in ChatGPT.

The specification is open source and published by the UCP authors, with documentation from Google and Shopify.

Related terms

Keep exploring

Commerce

Agentic commerce

Agentic commerce is shopping done by AI agents on a person's behalf: finding products, comparing options and, increasingly, completing the purchase.

Read

Commerce

Agentic Commerce Protocol (ACP)

The Agentic Commerce Protocol (ACP) is an open standard created by OpenAI and Stripe that lets AI agents, starting with ChatGPT, complete purchases with merchants on a buyer's behalf.

Read

Technical

Model Context Protocol (MCP)

The Model Context Protocol (MCP) is an open standard, introduced by Anthropic, that lets AI assistants connect to outside tools and data through MCP servers, in a common way.

Read

Technical

Structured data

Structured data is code added to a page, usually JSON-LD using the Schema.org vocabulary, that describes its content in a machine readable way, such as a product's price, an article's author or a company's logo.

Read
Full glossary