How AI Shopping Agents Discover Merchants Using UCP

The Discovery Problem

AI shopping agents have a fundamental problem: how do they know which stores exist, what they sell, and how to buy from them?

Before UCP, the answer was basically "hard-code it." Build a custom integration for Amazon, another for Walmart, another for Target. Maybe scrape some product feeds. It worked for a handful of big retailers, but it didn't scale. You couldn't build an agent that could shop at thousands of merchants without thousands of integrations.

UCP solves this with a standardized discovery mechanism.

How Discovery Works

Every UCP-enabled merchant hosts a manifest file at a predictable URL: /.well-known/ucp. This is similar to how robots.txt works for search engines or /.well-known/openid-configuration works for OAuth.

The manifest contains structured data about the merchant:

• Business name and description
• Product categories offered
• UCP capabilities supported (checkout, order management, returns)
• Accepted payment handlers
• The endpoint URL for UCP transactions

An agent can read this manifest and immediately understand what the merchant offers and how to interact with it. No custom integration. No API key negotiation. Just read the manifest and go.

The UCP Registry

Beyond individual merchant manifests, UCP includes a registry service. Think of it as a phonebook for UCP merchants.

Agents can query the registry to find merchants by category, location, product type, or capabilities. The registry returns a list of matching merchants with their manifest URLs.

Google Shopping acts as a major discovery layer here. When a consumer asks their agent to find running shoes, the agent can query Google Shopping's UCP interface to get a list of merchants that sell running shoes and support UCP checkout. The agent then reads each merchant's manifest and decides where to buy based on price, availability, shipping speed, and trust score.

Trust and Verification

Discovery alone isn't enough. Agents also need to know if a merchant is trustworthy.

UCP addresses this through:

• Verification status. Merchants can be verified by the registry, confirming they are who they claim to be.
• Trust scores. Built from transaction history, error rates, and consumer feedback. Agents use these to rank merchants.
• Payment handler guarantees. Registered payment handlers (Visa, Mastercard, PayPal) provide consumer protection on UCP transactions.

What This Means for Merchants

If you're a merchant, UCP discovery is how AI agents find you. Without it, you're invisible to the growing number of consumers who shop through agents.

The good news: if you're on Shopify, you can enable UCP with a toggle. Your products are automatically discoverable through the registry and Google Shopping's UCP layer.

For custom platforms, you need to:

1. Host a /.well-known/ucp manifest
2. Register with the UCP registry
3. Implement the transaction endpoints

Our getting started guide walks through the full process. The UCP readiness checker can tell you where your site stands right now.

The Network Effect

UCP discovery creates a strong network effect. More merchants means agents are more useful. More useful agents means more consumers adopt them. More consumers means more merchants want to be discoverable.

We're still in the early phase of this cycle. The merchants that join now get a head start on visibility, trust score accumulation, and agent relationships. Waiting costs more than joining.

Browse the Directory

The UCPList directory shows 57+ merchants already participating in the UCP ecosystem. Browse the list to see who is live, check their integration status, and understand what a production UCP endpoint looks like.