MCP Transport

When the merchant enables the MCP server, UCP shopping 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

Tools mirror the REST surface:

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