ucp-mcp

MCP server for UCP. Gives your LLM access to all the UCP schemas, specs, and a few handy tools.

Why?

UCP (Universal Commerce Protocol) defines how commerce stuff should talk to each other — checkout flows, payments, fulfillment, etc. This MCP server lets you query those definitions, validate payloads against them, and poke around merchant discovery endpoints.

Tools

• list_schemas — browse all 50+ UCP schemas
• get_schema — grab a specific schema by name
• validate_json — check if your JSON matches a schema
• get_openapi_spec — the REST API spec (OpenAPI 3.1)
• get_openrpc_spec — the JSON-RPC spec
• list_capabilities — what UCP can do (checkout, payment, fulfillment, etc)
• get_discovery_profile_schema — the /.well-known/ucp schema
• discover_merchant — hit a merchant's discovery endpoint and see what they support
• generate_checkout_request — spit out a sample checkout payload

Setup

git clone https://github.com/sakinaroufid/ucp-mcp.git
cd ucp-mcp
npm install
npm run build

Add to Cursor / Claude Desktop

Drop this in your MCP config:

{
  "mcpServers": {
    "ucp": {
      "command": "node",
      "args": ["/path/to/ucp-mcp/dist/index.js"]
    }
  }
}

Quick examples

Find checkout schemas:

list_schemas(category: "checkout")

Generate a test checkout:

generate_checkout_request(
  items: [
    { name: "Keyboard", quantity: 1, price_cents: 14900 }
  ],
  currency: "USD"
)

Check what a merchant supports:

discover_merchant(merchant_url: "https://shop.example.com")

What's in UCP

| Thing | What it does | |-------|-------------| | Checkout | Cart, line items, tax calc | | Order | Order events — shipped, delivered, returned | | Payment | Payment methods, tokenization | | Fulfillment | Shipping options, delivery |

Plus extensions for discounts, buyer consent, and AP2 mandates.

Dev

npm install
npm run build
npm start

Links

• UCP spec
• UCP repo
• MCP docs

License

Apache-2.0