Definition
Universal Commerce Protocol (UCP)
An open standard — announced January 2026, led by Google with Shopify and other commerce partners — that lets AI agents discover a store's services, capabilities, and payment options from one JSON manifest at /.well-known/ucp.
Definition
The Universal Commerce Protocol (UCP) is an open, Apache-2.0-licensed standard for agentic commerce, announced in January 2026 and developed by Google together with Shopify, Etsy, Target, Walmart, and a broad group of commerce and payments partners. A business publishes a JSON manifest at /.well-known/ucp declaring its protocol version, services, capabilities (checkout, cart, catalog search and lookup, fulfillment, discounts), transports (REST, MCP, A2A, embedded), and payment handlers. Any agent that speaks the protocol — Google's AI Mode and Gemini, ChatGPT, Claude, platform agents — can read that manifest and transact with the store without a custom integration.
How discovery and negotiation work
An agent fetches the store's manifest, reads the declared versions and capabilities, and computes the intersection with what it supports itself — that intersection is what the transaction can do. Capabilities use reverse-domain names (dev.ucp.shopping.checkout, with vendor extensions like dev.shopify.catalog), so anyone can extend the protocol in their own namespace without a central committee. Checkout runs as a state machine with explicit escalation: when a step needs a human — payment approval, an edge case the agent can't handle — the protocol hands control back with the transaction context intact.
Where it stands
Adoption is moving fastest where platforms do the work: Shopify publishes UCP manifests for storefronts automatically, with live MCP endpoints, checkout and cart capabilities, and payment handlers included. Google has been extending the protocol through 2026 — multi-item carts, checkout rollouts beyond the US, and new categories like hotel booking and food delivery. The practical consequence for merchants: having a manifest is becoming table stakes, and the differentiating question is shifting to the quality of the data and answers behind it.
UCP vs ACP
Two parallel standards define the space. The Agentic Commerce Protocol (ACP), announced by OpenAI and Stripe in September 2025, powers checkout inside ChatGPT. UCP followed in January 2026 with a broader consortium and a transport-flexible design compatible with the Agent Payments Protocol (AP2) for authorization. They compete for mindshare but not exclusively — most platforms and brands will end up speaking both, and on major platforms both are increasingly provisioned automatically. You can check any store's UCP surface with Kinect's free UCP Test at trykinect.ai/ucp-test.
Related concepts
Agentic Commerce
Commerce in which AI agents — the shopper's or the brand's — mediate discovery, comparison, decision, and increasingly checkout.
Buyer Agent
An AI agent that shops on a consumer's behalf — discovering products, comparing options, and increasingly completing checkout — loyal to the shopper, not to any store.
Brand Agent
An AI agent that works for the brand: it sells to shoppers on the brand's own site, represents the brand accurately to outside buyer agents, and keeps the brand's machine-readable surfaces correct.
Agent Storefront
A storefront surface built for AI agents rather than human browsers — structured product data, brand facts, and policies that a shopping agent can read, reason over, and buy from.
See universal commerce protocol (ucp) in action.
Book a call to talk through your store — live on your catalog the same day.