Bookshop Example

A minimal CAP bookshop sample that exposes its service via the Model Context Protocol (MCP), letting AI agents and LLM tools query it directly.

Official CAP MCP docs: https://cap.cloud.sap/docs/guides/protocols/mcp

Setup

npm install

Run

cds watch

The MCP server starts automatically and is registered with local MCP clients (Claude Code, Opencode).

How it works

The CatalogService in srv/cat-service.cds is annotated with @mcp, which is all that's needed to expose it as an MCP server:

annotate CatalogService with @mcp;

The adapter creates three tools per service:

Tool	Purpose
describe	Returns the data model (entities, actions, functions)
query	Reads data — supports select, where, orderBy, limit, etc.
call_action	Invokes unbound actions/functions (e.g. submitOrder, checkAvailability)

Try it

With Claude Code or Opencode running, just ask:

list books with authors and genres

Inspect tools

npm run inspector

Opens the MCP Inspector at http://localhost:5173. Connect to http://localhost:4004/mcp/browse to browse tools interactively.