← kylerisley.com

UCP Explorer

A transparency tool for the Universal Commerce Protocol

This tool lets you see exactly what happens when an AI agent connects to a store's Universal Commerce Protocol (UCP) endpoints. Enter any domain below and the tool will:

  1. Fetch the UCP manifest at /.well-known/ucp to discover what services and capabilities the store advertises
  2. Connect to the MCP endpoint to list the tools the store makes available to AI agents (catalog search, cart management, checkout, etc.)
  3. Let you interact with those tools directly — search the catalog, ask about store policies, and view product details

Every request is shown with its URL, HTTP status, and raw JSON response so you can see the full back-and-forth between agent and merchant.

About UCP

What is the Universal Commerce Protocol?

UCP is an open standard for AI agents to connect and transact with any merchant. It is governed by the UCP Tech Council, whose founding members are Google, Shopify, Etsy, Target, and Wayfair. Amazon, Meta, Microsoft, Salesforce, and Stripe joined the Tech Council in April 2026. The specification is published under the Apache License 2.0.

What problem does UCP solve?

Commerce is complex — payment options and rules differ based on the cart, buyer, and market; discounts have stacking and combination rules; fulfillment options multiply with every permutation. UCP provides a standard way for agents and merchants to negotiate these capabilities dynamically, rather than requiring custom integrations for every merchant.

How is UCP structured?

UCP uses a layered architecture. The Shopping service defines core transaction primitives: checkout session, line items, totals, messages, and status. Capabilities add major functional areas — Checkout, Orders, Catalog — each independently versioned. Extensions augment capabilities with domain-specific schemas via composition, allowing merchants to declare bespoke functionality. Merchants declare what they support, agents discover these capabilities and negotiate what they can handle.

How does discovery work?

Merchants publish a JSON manifest at /.well-known/ucp that declares their supported services, capabilities, and endpoint URLs. AI agents fetch this manifest to discover what a merchant offers and how to interact with them. This is the starting point for any UCP interaction.

What role does MCP play?

UCP is transport-flexible — it supports REST, GraphQL, JSON-RPC, A2A, and MCP. The idea is to swap the transport and envelope, not the business logic. MCP (Model Context Protocol) is one of these transport options, and the one this tool uses to interact with store endpoints. Shopify exposes MCP endpoints that implement UCP capabilities as callable tools like search_catalog, get_product_details, update_cart, and search_shop_policies_and_faqs.

What does this tool do?

This tool performs the same requests an AI agent would make when interacting with a store via UCP. It fetches the UCP manifest, connects to the MCP endpoint, lists available tools, and lets you call those tools interactively. All requests and responses are shown transparently so you can see exactly what data is exchanged between agent and merchant.

Which stores support UCP?

The UCP Tech Council includes Google, Shopify, Etsy, Target, Wayfair, Amazon, Meta, Microsoft, Salesforce, and Stripe. Shopify currently provides UCP-compliant MCP servers for stores on its platform. The standard is open — any platform or merchant can implement it. Actual store-level availability depends on the platform and merchant.

Where can I learn more?

The official UCP specification is at ucp.dev. Shopify's engineering blog post on building UCP is at shopify.engineering/ucp. Shopify's implementation documentation is at shopify.dev/docs/agents.

This tool is an independent project made for educational purposes. It is not affiliated with, endorsed by, or associated with Shopify or any member of the UCP Tech Council.