generated: '2026-08-06'
method: derived
source: mcp/bartesian-ucp-shopping-tools.json
note: >-
  Derived from the live tool inputSchemas the Bartesian storefront's own MCP
  endpoint returns to an anonymous caller, not from an OpenAPI (Bartesian
  publishes none). Entity internals are defined in the referenced ucp.dev JSON
  Schemas; recorded here are the entities this endpoint actually exposes, the
  identifier formats it publishes, and the relationships its tool surface
  implies.
id_scheme:
  style: Shopify global ID (GID)
  formats:
    cart: 'gid://shopify/Cart/abc123'
    checkout: 'gid://shopify/Checkout/abc123'
    order: 'gid://shopify/Order/123'
  source: id parameter descriptions in the live tool schemas
entities:
- name: product
  schema: https://ucp.dev/2026-04-08/schemas/shopping/catalog_lookup.json
  operations: [search_catalog, lookup_catalog, get_product]
  read_only: true
  description: A Bartesian catalog product (cocktail machine or capsule pack) with
    its variants, options, pricing and real-time availability.
  storefront_json: https://bartesian.com/products.json
  storefront_fields: [id, title, handle, body_html, published_at, created_at, updated_at,
    vendor, product_type, tags, variants, images, options]
- name: cart
  schema: https://ucp.dev/2026-04-08/schemas/shopping/cart.json
  operations: [create_cart, get_cart, update_cart, cancel_cart]
  fields: [line_items, buyer, context, attribution, fulfillment, discounts]
  description: A mutable basket of catalog line items held for an agent session.
- name: checkout
  schema: https://ucp.dev/2026-04-08/schemas/shopping/checkout.json
  operations: [create_checkout, get_checkout, update_checkout, complete_checkout, cancel_checkout]
  fields: [payment, line_items, buyer, context, attribution, cart_id, fulfillment,
    discounts]
  description: A purchase session carrying buyer, fulfillment and payment state; completing
    it places an order and requires both buyer approval and an idempotency key.
- name: order
  schema: https://ucp.dev/2026-04-08/schemas/shopping/order.json
  operations: [get_order]
  read_only: true
  description: The current-state snapshot of a placed order.
- name: payment_instrument
  operations: [create_checkout, update_checkout, complete_checkout]
  fields: [id, handler_id, type, billing_address]
  description: A card or wallet token supplied on checkout.payment.instruments[]. The
    agent never handles raw card data; handler_id names one of the store's declared
    payment handlers.
- name: message
  schema: https://ucp.dev/2026-04-08/schemas/shopping/types/message.json
  description: Error, warning or info message attached to any cart, checkout or order
    result; carries code, severity and an RFC 9535 JSONPath to the component it refers
    to.
relationships:
- from: checkout
  to: cart
  kind: belongs_to
  via: cart_id
  confidence: high
  note: cart_id is a declared top-level property of the checkout object in the live
    create_checkout schema - an explicit id reference, not an inference
- from: cart
  to: product
  kind: has_many
  via: line_items[] referencing catalog product/variant identifiers
  confidence: high
- from: checkout
  to: product
  kind: has_many
  via: line_items[]
  confidence: high
- from: checkout
  to: payment_instrument
  kind: has_many
  via: payment.instruments[]
  confidence: high
- from: checkout
  to: order
  kind: has_one
  via: complete_checkout places the order and returns its order ID
  confidence: high
- from: order
  to: product
  kind: has_many
  via: order line items
  confidence: medium
- from: cart
  to: message
  kind: has_many
  via: messages[]
- from: checkout
  to: message
  kind: has_many
  via: messages[]
- from: order
  to: message
  kind: has_many
  via: messages[]
capabilities_shaping_the_model:
- {id: dev.ucp.shopping.cart, effect: cart entity}
- {id: dev.ucp.shopping.checkout, effect: checkout entity}
- {id: dev.ucp.shopping.order, effect: order entity}
- {id: dev.ucp.shopping.catalog.search, effect: search_catalog over the product entity}
- {id: dev.ucp.shopping.catalog.lookup, effect: 'lookup_catalog / get_product; batch
    lookup capped at 10 ids'}
- {id: dev.shopify.catalog, effect: Shopify storefront catalog extension over the two
    catalog capabilities}
- {id: dev.ucp.shopping.fulfillment, effect: 'fulfillment on cart and checkout; single
    destination only (allows_multi_destination.shipping = false)'}
- {id: dev.ucp.shopping.discount, effect: discounts on cart and checkout}
render: null
x-evidence:
  fetched: '2026-08-06'
  url: https://bartesian.com/api/ucp/mcp
  http_status: 200
  note: derived from a live anonymous tools/list response, saved verbatim alongside