# MCP for Commerce - Definition > What MCP for commerce means, how it differs from ACP and UCP, which tools a store exposes, and why discovery is still unsolved. Source: https://angeo.dev/mcp-commerce-definition/ Updated: 2026-10-17 Canonical definition # MCP for Commerce - Definition **MCP for commerce means using the Model Context Protocol (MCP) so an AI assistant can call a store's tools - search the catalogue, add to cart, place an order - through one uniform interface.** MCP is an open standard published by Anthropic in November 2024 and moved to the Linux Foundation in December 2025. A store runs an MCP server exposing typed tools, and any MCP-capable client can invoke them. Unlike ACP and UCP, MCP is not a commerce protocol: it is transport and tool plumbing that commerce can be built on. **In one sentence** A universal adapter between AI assistants and software, which a store can use to expose its catalogue and checkout as callable tools rather than as pages to be scraped. ## How it differs from ACP and UCP | | MCP | ACP | UCP | | Defines | Tool calling | Buyer-agent-merchant purchase model | Capability discovery and transaction | | Commerce semantics | None - you design the tools | Yes | Yes | | Discovery | The client is given a server URL | Platform feed onboarding | `/.well-known/ucp` | | Governance | Open standard, Linux Foundation | OpenAI and Stripe | Google and retail coalition | The three are not competitors. UCP explicitly lists `mcp` as a transport binding alongside `rest`, `a2a` and `embedded`, and ACP added MCP compatibility in its 2026-04-17 release. In practice MCP is how the other two get carried. ## What a commerce MCP server exposes Tools are typed functions with a JSON schema and a description the model reads to decide whether to call them. A minimal store server: | Tool | Does | Annotation | | `search_products` | Keyword and filter search over the catalogue | Read-only | | `get_product` | Full detail for one SKU, including variants | Read-only | | `create_cart` / `add_to_cart` | Build a guest cart | Write | | `set_shipping_information` | Address, contact, shipping method | Write | | `place_order` | Submit the order | Write, **destructive** | Tool annotations matter more than they look. A client uses them to decide what needs human confirmation. A `place_order` tool that is not marked destructive invites an assistant to call it without asking. ## Is agentic checkout real? Yes - with caveats worth stating plainly. We published a demo of Claude placing a real order on a live Magento 2 store over MCP: product search, cart, shipping, checkout, ending in an order number and a payment link. No browser automation. The general concept is covered in [agentic checkout](https://angeo.dev/agentic-checkout-definition/). **Not something to enable casually** An MCP server that can place orders is a write path into your store. Guardrails belong *server-side*, not in the tool description: authentication, rate limits, quantity and value ceilings, read-only by default, and payment handled by the payment provider rather than the tool. ## Discovery is the unsolved part MCP has no equivalent of `/.well-known/ucp`. A client must be given the server URL - through a connector directory, a manual configuration, or a UCP profile advertising an `mcp` transport binding. There is a second, subtler problem: even a connected server competes with the model's built-in behaviour. In our own testing, a direct question about the store reaches the connector, while a cold product query in a fresh conversation often goes to the assistant's built-in search instead - even after tuning tool descriptions, titles and server instructions. Being callable is not the same as being called. ## On Magento 2 - [angeo/module-mcp-server](https://angeo.dev/modules/mcp-server/) - read-only, rate-limited catalogue access - [angeo/module-mcp-checkout](https://angeo.dev/modules/mcp-checkout/) - guest cart through placed order, with guardrails enforced server-side and pay-by-link support Both MIT-licensed. Walkthrough: [MCP checkout for Magento 2](https://angeo.dev/docs/mcp-checkout/). Live demo: [Claude places a real order via MCP](https://angeo.dev/ai-agent-checkout-in-magento-2-claude-places-a-real-order-via-mcp/). ## Questions Is MCP a commerce protocol? No. MCP defines how an AI assistant calls tools on an external system and carries no commerce semantics. ACP and UCP define the commerce model; MCP is one way to transport it. Can an AI agent really place an order in Magento over MCP? Yes. A published demo shows Claude completing a real order on a live Magento 2 store, from search through checkout to an order number, with no browser automation. It requires an MCP server on the store and deliberate server-side guardrails. How does an AI client find my MCP server? It has to be told. MCP has no well-known discovery path, so the URL arrives through a connector directory, manual configuration, or a UCP profile advertising an `mcp` transport binding. Do I need MCP if I already publish a UCP profile? Not necessarily, since UCP works over REST. MCP helps when assistants that speak MCP natively should reach the catalogue directly. If a profile advertises an `mcp` binding, the endpoint behind it must implement the methods that binding's schema describes. Is exposing checkout over MCP safe? Only with server-side guardrails. Treat an order-placing tool as a write path into the store: authentication, rate limits, value and quantity ceilings, destructive annotations, and payment handled by the payment provider rather than the tool. ## Related - [Agentic checkout - definition](https://angeo.dev/agentic-checkout-definition/) - [Commerce agent - definition](https://angeo.dev/commerce-agent-definition/) - [UCP - definition](https://angeo.dev/ucp-definition/) - [ACP - definition](https://angeo.dev/acp-definition/) - [MCP and agentic commerce glossary](https://angeo.dev/docs/mcp-glossary/) - [MCP for Magento](https://angeo.dev/magento-mcp-server/) - [WebMCP - definition](https://angeo.dev/webmcp-definition/) - [MCP account linking - definition](https://angeo.dev/mcp-account-linking-definition/) Verified 28 August 2026. Disclosure: we publish the open-source MCP modules referenced above and operate the demo store used in the linked video. ## More on this topic - [AP2 (Agent Payments Protocol) - Definition](https://angeo.dev/ap2-definition/) - [Magento MCP Servers Compared (2026): 17 Projects](https://angeo.dev/magento-mcp-servers-compared/) - [MCP Modules for Magento 2 - Configuration Reference](https://angeo.dev/docs/mcp/) - [Magento Agentic Commerce Hub 2026: ACP - UCP - AP2](https://angeo.dev/magento-agentic-commerce-hub/) - [Agentic Commerce for Magento: 12 Merchant Questions Answered](https://angeo.dev/agentic-commerce-magento-questions/) - [Claude Commerce Agents on Magento 2](https://angeo.dev/claude-commerce-agents-magento/) ## Sources - [MCP specification 2026-07-28](https://modelcontextprotocol.io/specification/2026-07-28) - [MCP specification repository](https://github.com/modelcontextprotocol/modelcontextprotocol) - [angeo/module-mcp-server on GitHub](https://github.com/angeo-dev/module-mcp-server) Links checked 23 September 2026.