MCP Transport

When the merchant enables the MCP server, UCP shopping and common capabilities are available as MCP tools at:

Endpoint: https://{shop-domain}/mcp

The OpenRPC schema URL is published in the discovery profile under the MCP transport binding.

Tools

The catalog and cart tools below cover part of the available surface. For checkout, orders, identity, locations, and other enabled capabilities, discover tools from the MCP server and read the shopping and common OpenRPC schemas in the profile. Do not derive tool names from capability identifiers.

Tool	REST equivalent
`search_catalog`	`POST /catalog/search`
`lookup_catalog`	`POST /catalog/lookup`
`get_product`	`POST /catalog/product`
`create_cart`	`POST /carts`
`get_cart`	`GET /carts/{id}`
`update_cart`	`PUT /carts/{id}`
`cancel_cart`	`POST /carts/{id}/cancel`

These UCP tool names replace the former Storefront MCP names (search_products, get_product, create_cart, add_cart_lines, update_cart_lines, remove_cart_lines).

Required metadata

Each tool requires your platform profile in call metadata:


{
  "meta": {
    "ucp-agent": {
      "profile": "https://your-platform.example/.well-known/ucp"
    }
  }
}

cancel_cart additionally requires meta.idempotency-key.

Connecting an agent

Enable UCP and the MCP server on the channel — see Activating UCP
Point your agent to https://{shop-domain}/mcp
Authenticate using a channel API key or an allowed agent access tier
Pass meta.ucp-agent.profile on each tool call
Discover available tools from the MCP server or the OpenRPC schema in the discovery profile