Universal Commerce Protocol (UCP) Explained: Who Backs It and What Merchants Do

The Universal Commerce Protocol (UCP) is an open standard that lets AI agents and platforms search a store's catalog, build carts, check out and track orders in one common format. Google and Shopify are its founding organizations, and it powers checkout in Google's AI Mode and Gemini.

UCP launched on 11 January 2026 and has shipped dated releases since, the latest being 2026-08-25. For merchants, the main questions are who controls it, what it covers and whether you need to do anything. This guide answers each, checked on 6 November 2026.

What UCP is

The UCP site describes it as "The common language for platforms, agents, and businesses." The UCP GitHub repository calls it "An open standard enabling interoperability between various commerce entities." It is Apache 2.0 licensed.

Without a shared standard, every AI app would need a custom integration with every store. UCP gives them one format for the whole journey. Google's technical launch post, dated 11 January 2026, says it "standardizes the full commerce journey - from discovery and consideration to purchase and order management."

Who backs UCP

Founders and co-developers

Google lists Shopify, Etsy, Wayfair, Target and Walmart as collaborators.

The UCP site now lists a longer set of co-developers by vertical. For shopping it names Google, Shopify, Etsy, Wayfair, Target, Walmart, Amazon, Microsoft, Meta, Salesforce and Stripe. It also lists lodging co-developers (such as Booking.com, Expedia Group, Hilton and Marriott) and food co-developers (DoorDash, Square, Toast, Uber Eats). Separate endorsers include Adyen, Mastercard, PayPal and Visa.

Governance

The project's governance document sets out how decisions are made:

• A Governing Council of five. Google and Shopify, as founding organizations, each hold one permanent seat. Three seats are elected.
• "Google acts as the custodian of the UCP.dev domain."
• "Google holds proxy vote for all open seats until Dec 2028."
• Domain Tech Councils for Shopping, Food, Lodging and Payments. The Shopping council has 16 members, four permanent from each of Google and Shopify.
• The Payments council's permanent members include Google, Shopify, Adyen, Ant International, Coinbase, Global Payments, PayPal and Stripe.

There is no independent foundation behind UCP today. That is a real difference from MCP and A2A, which sit in the Linux Foundation's Agentic AI Foundation.

What UCP covers

The UCP site lists "Catalog Search and Lookup, Cart Building, Identity Linking, Checkout, and Order Management." The repository also mentions extensions such as discounts and fulfillment.

How it connects

UCP is "transport agnostic." The repository says businesses can offer capabilities via "REST APIs, MCP (Model Context Protocol), or A2A." Google's launch post describes the same three routes: "APIs, Agent2Agent (A2A), and the Model Context Protocol (MCP)."

For payments, Google's post says UCP "is compatible with Agent Payments Protocol (AP2)." Our AP2 explainer covers those.

Release history

UCP uses dated versions. The releases page lists:

• v2026-01-11 and v2026-01-23: the launch versions, including docs on capability maturity levels.
• v2026-04-08: added Cart, Catalog search and lookup, OAuth 2.0 identity linking, and request and response signing.
• v2026-08-25 (latest as of 6 November 2026): groundwork for Food and Lodging, grocery features, and payment additions such as 3DS2, payment schedules and split payments. It also restructured the fulfillment schema, a breaking change.

The UCP site says a "Lodging draft specification now available" and lists food as "coming soon."

Where UCP is used

Google

Google's UCP merchant docs name "AI Mode in Google Search and Gemini web (app coming soon)." Merchants can "Use your existing Merchant Center account shopping feeds." Native checkout is the default; embedded checkout is "An additional optional path for specific, approved merchants." The docs invite lodging and food businesses to join a waitlist.

In May 2026, Google said UCP checkout would roll out in Canada and Australia "in the coming months, and later to the U.K." Google said on 4 November 2026 that direct checkout, powered by UCP, "is expanding to Canadian shoppers on AI Mode in Google Search and the Gemini app."

Shopify

Shopify's agents docs say "Shopify's MCP tools implement UCP at every step of the buyer journey." Agents must "Define a profile so Shopify can verify your agent," and "Higher trust tiers unlock broader access, including direct checkout completion."

Stripe

Stripe's UCP docs say Stripe "is a member of the UCP Tech Council" and offer a Stripe Payments handler for card and Apple Pay credentials in UCP checkouts.

Shopify's Storefront MCP moved to UCP

If you or a developer built on Shopify's Storefront MCP endpoint, this matters. Shopify's Storefront MCP page says "The catalog and cart tools on https://{shop}/api/mcp were removed." It adds: "UCP now provides these capabilities at https://{shop}/api/ucp/mcp."

The replacements are:

• Catalog: search_catalog, lookup_catalog and get_product
• Cart: create_cart, get_cart, update_cart and cancel_cart
• Policies and FAQs: ask_business
• Checkout URLs: from Checkout MCP

Two gotchas. Shopify says to "Include an agent profile in every request to /api/ucp/mcp." And "Each update_cart request replaces the full cart," so send every line item you want to keep. Customer Accounts MCP is unchanged. Our Shopify MCP server guide has the full tool list.

What merchants should do

1. Shopify merchants: you mostly get UCP through Shopify. Review Agentic Storefronts in your admin and keep your catalog clean. If you have custom agent code, move it to /api/ucp/mcp. See Shopify agentic commerce.
2. Google Merchant Center users: check Merchant Center for UCP checkout onboarding as it rolls out in your country.
3. Custom platforms: read the spec and samples, and decide which capabilities to support.
4. Everyone: make product data complete and accurate, and decide your policy for agent-placed orders.

Comparing with OpenAI's approach? Read UCP vs ACP.

Next step

eSEOspace designs and builds stores through our Shopify website design and ecommerce services, and we can review how your catalog and checkout look to AI agents. Projects are quoted individually, and we cannot promise placement in Google or any AI channel. Explore related standards on the agent protocols hub.

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