AI shopping assistants are moving beyond recommendations. The goal now is action: discovery, checkout, and purchase inside the same conversational flow.
That is hard today because every store and payment setup behaves differently. Google’s Universal Commerce Protocol (UCP) is an open-source standard meant to give agents a shared language to talk to businesses and payment providers, while still working with existing retail infrastructure. UCP is also compatible with Agent Payments Protocol (AP2) for secure agentic payments support.
Google has already built a reference implementation so eligible businesses can sell directly inside conversational experiences like AI Mode in Search and the Gemini app. Merchants remain the Merchant of Record, and UCP supports an embedded option that lets retailers keep a customized checkout experience.
Why This Matters Now
Think about how you shop online today. You browse a website, add items to your cart, and check out on that site. Pretty straightforward.
Now imagine telling an AI assistant: “Find me a lightweight suitcase under $200 and buy the best one.” The assistant needs to figure out which stores carry suitcases, compare options, check what payment methods work, apply any discounts you have, and complete the purchase. That is a lot of moving parts, and right now, every store handles these things differently.
UCP creates a standard way for AI agents to ask stores: What can you do? What payment methods do you accept? How do I create a checkout? It is like giving every AI shopping assistant a universal translator for online commerce.
How It Actually Works
The technical setup is straightforward. A business can publish a JSON file at a specific web address, /.well-known/ucp on their domain. When an AI agent wants to shop there, it checks that file first to see what the store supports.
The store’s file might say: “I can handle the checkout. I support discounts and multiple fulfillment options. I work with payment handlers like Google Pay or Shop Pay.” The AI agent responds with what it can support. They meet in the middle, and the transaction happens using only the features both sides can handle.
Once connected, the AI can create a checkout session, add items, apply discount codes, and get updated totals. In Google’s example flow, checkout is treated like a session you can create and update. A POST request creates a checkout session, then a PUT request updates the same session, such as applying a discount code.
The system is designed to be flexible rather than rigid. That matters because commerce rules vary by region, product type, inventory constraints, and merchant policies.
The Payment and Security Side
UCP does not replace existing payment systems. It works alongside them and is compatible with Agent Payments Protocol (AP2) for secure AI-driven transactions.
Here is how it plays out. The merchant lists which payment handlers they accept, like Shop Pay or Google Pay. The agent declares what it can provide. The final checkout reflects what works for that cart and that buyer.
For people using Google’s AI Mode or Gemini, there is a clear convenience win. If a shopper has shipping and payment details saved in Google Wallet, those can be used with permission, reducing checkout friction.
What Online Stores Need to Do
If you run an online store, this shift has real implications.
Your product data needs to be cleaner than ever. When people discover products through conversation instead of browsing, accurate titles, current availability, clear pricing, and shipping details become critical. This is no longer housekeeping. It affects whether agents can find and recommend your products.
Checkout needs to work like an API. You need systems that can create checkout sessions on demand, apply discounts programmatically, and return clear status updates. If your checkout relies on fragile front-end workarounds, it will be harder for agents to complete purchases reliably.
The full order lifecycle matters. UCP is not just about completing purchases. It also supports identity linking and order management, and it is designed to evolve. Your backend should generate consistent order IDs, track fulfillment reliably, and provide post-purchase updates in a structured way.
For Google’s implementation specifically, you will need Merchant Center. Google states that participation requires an active Merchant Center account and eligible products for checkout. You also need to follow their integration guides and complete the UCP integration steps.
Tracking and Measurement Gets Tricky
One thing that catches many businesses off guard is measurement. When purchases happen inside AI Mode or Gemini instead of on your website, browser-based analytics can miss them.
You need server-side purchase confirmation that captures order ID, value, currency, and timestamps independently of browser tracking. Otherwise, you risk double-counting purchases or missing them entirely.
Attribution also gets messy. A purchase that begins and ends inside an AI shopping flow does not fit neatly into traditional source and medium reports. Most teams will need to adjust how they classify and reconcile these conversions.
What Happens Next
UCP is early, but it is already concrete enough to prepare for. The foundation is simple: publish a UCP manifest at /.well-known/ucp so agents can discover your capabilities.
From there, checkout becomes a session-based flow that an agent can create and update. The practical takeaway for merchants is to make product data reliable, make checkout accessible programmatically, and make order and conversion signals robust.
If you want to participate in Google’s implementation, Google states you need an active Merchant Center account and eligible products. At this time, participation is available only to U.S.-based merchants. The published next steps are to follow Google’s integration guide, complete the merchant interest form, and then complete the UCP integration steps
The shift from browsing-based shopping to conversation-based shopping is coming. UCP is one of the strongest early attempts to make that shift work across platforms and providers. Even if the ecosystem evolves beyond one standard, the direction is clear. Shopping is becoming agent-driven.
How Conversios is preparing (upcoming features)
Conversios has already started researching UCP and related development approaches for Shopify and WooCommerce. Upcoming work includes UCP readiness checks, AI-focused feed validation, and stronger server-side conversion matching to keep purchase reporting accurate as AI-led checkout experiences evolve.
Frequently Asked Questions
Q. What exactly is the Universal Commerce Protocol?
UCP is an open-source standard that gives AI shopping agents a consistent way to discover what a business supports and then complete commerce actions like checkout and order management using shared conventions.
Q. Who created UCP and who is supporting it?
UCP is developed by Google in collaboration with Shopify, Etsy, Wayfair, Target, and Walmart, and is endorsed by 20+ partners across the ecosystem. Examples listed include Adyen, American Express, Best Buy, Flipkart, Mastercard, Stripe, The Home Depot, Visa, and Zalando.
Q. Do I need to rebuild my entire online store to support UCP?
Not necessarily. The changes depend on your setup. At a minimum, you need to publish a UCP manifest, ensure checkout can be accessed programmatically, and keep product data clean. Platform-level support may reduce work for merchants on systems like Shopify.
Q. How does UCP handle payments securely?
UCP works with existing payment processors and supports a modular payment handler approach. It is compatible with AP2 for secure agentic payments support.
Q. Will this work on platforms other than Google?
Yes. UCP is designed as an open standard that other agents and platforms can implement. Different ecosystems may adopt it at different speeds.
Q. What information does the /.well-known/ucp file contain?
It is a JSON manifest that describes what your store can do. That includes supported services like checkout, extensions such as discounts and fulfillment choices, accepted payment handlers, and links to relevant endpoints.
Q. How is this different from current shopping APIs?
Most commerce APIs are custom. UCP standardizes discovery and core workflows so agents can use a consistent approach across any business that supports the protocol.
Q. What happens to analytics and conversion tracking?
When purchases complete inside an AI interface, browser-based tracking can miss them. Strong server-side conversion tracking and deduplication become essential. You may also need to update attribution rules to classify agent-led purchases correctly.
Q. Do customers see a different checkout experience?
It depends. Some implementations may keep checkout embedded in the conversational surface. Others may redirect the shopper to the merchant site for confirmation. UCP is flexible enough to support different models.
Q. Is UCP only for large retailers?
No. While early partners are large brands, the protocol is designed to be accessible. If commerce platforms add native support, smaller merchants can benefit without building custom integrations.
Q. What is the timeline for adoption?
UCP is newly announced and early in rollout. Google’s reference implementation is live, and participation requires Merchant Center eligibility plus completing Google’s integration steps. Broader adoption will depend on platform and ecosystem rollout.
Q. Can AI agents make purchases without explicit user permission?
No. The design assumes proper user authorization for payment access and purchase completion. Users remain in control of when transactions are executed.