generated: '2026-09-13'
method: derived
source: mcp/hni-hearthnhome-tools.json (live tools/list inputSchemas, probed 2026-09-13)
note: >-
  Derived from the JSON Schema inputSchemas of the 13 MCP tools. There is no OpenAPI and no object
  reference to cross-check against, so this graph reflects request shapes only — response schemas are
  not published by tools/list and could not be observed, because tools/call is authentication-gated.
entities:
  - name: Product
    id_field: catalog.id
    description: A catalogue item on the Hearth & Home Technologies storefront.
    surfaced_by: [search_catalog, lookup_catalog, get_product]
  - name: Variant
    description: A selectable configuration of a Product, addressed via catalog.selected.
    surfaced_by: [lookup_catalog, get_product]
  - name: Cart
    id_field: id
    description: A mutable collection of line items with buyer, fulfillment and discount context.
    surfaced_by: [get_cart, create_cart, update_cart, cancel_cart]
    fields: [line_items, buyer, context, attribution, fulfillment, discounts]
  - name: Checkout
    id_field: id
    id_format: 'gid://shopify/Checkout/abc123'
    description: A cart promoted to a payable transaction, carrying payment instruments and totals.
    surfaced_by: [get_checkout, create_checkout, update_checkout, complete_checkout, cancel_checkout]
    fields: [payment, line_items, buyer, context, attribution, cart_id, fulfillment, discounts]
  - name: LineItem
    description: A quantity of a Product/Variant inside a Cart or Checkout.
  - name: Order
    id_field: id
    description: The record produced by a completed Checkout. Read-only on this surface.
    surfaced_by: [get_order]
  - name: Buyer
    description: Identity and contact details attached to a Cart or Checkout.
  - name: Address
    description: Billing or shipping address.
    fields: [street_address, extended_address, address_locality, address_region, postal_code, address_country, first_name]
    standard: address_country is ISO 3166-1 alpha-2
  - name: PaymentInstrument
    description: A card, token or wallet instrument on a Checkout.
    fields: [id, handler_id, type, billing_address, credential]
    note: Apple Pay uses type "card" with an apple_pay_token credential and requires billing_address.
  - name: PaymentHandler
    description: The processor that generated a PaymentInstrument, referenced by handler_id.
  - name: Discount
    description: A promotion applied to a Cart or Checkout (UCP dev.ucp.shopping.discount capability).
  - name: Fulfillment
    description: Shipping method and destination (UCP dev.ucp.shopping.fulfillment capability).
    note: The UCP profile declares method_combinations [["shipping"]] and no multi-destination support.
  - name: Money
    description: An integer amount in ISO 4217 minor units paired with a currency code.
    example: '{"amount": 2500, "currency": "USD"}'
  - name: AgentProfile
    description: The calling agent's UCP profile, referenced by meta.ucp-agent.profile and fetched by the server.
relationships:
  - from: Cart
    to: LineItem
    kind: has_many
    via: cart.line_items
  - from: Cart
    to: Buyer
    kind: has_one
    via: cart.buyer
  - from: Cart
    to: Fulfillment
    kind: has_one
    via: cart.fulfillment
  - from: Cart
    to: Discount
    kind: has_many
    via: cart.discounts
  - from: Checkout
    to: Cart
    kind: belongs_to
    via: checkout.cart_id
  - from: Checkout
    to: LineItem
    kind: has_many
    via: checkout.line_items
  - from: Checkout
    to: PaymentInstrument
    kind: has_many
    via: checkout.payment.instruments
  - from: Checkout
    to: Buyer
    kind: has_one
    via: checkout.buyer
  - from: Checkout
    to: Fulfillment
    kind: has_one
    via: checkout.fulfillment
  - from: Checkout
    to: Discount
    kind: has_many
    via: checkout.discounts
  - from: PaymentInstrument
    to: Address
    kind: has_one
    via: instrument.billing_address
  - from: PaymentInstrument
    to: PaymentHandler
    kind: belongs_to
    via: instrument.handler_id
  - from: Order
    to: Checkout
    kind: belongs_to
    via: produced by complete_checkout
  - from: LineItem
    to: Product
    kind: belongs_to
    via: product/variant identifier
id_conventions:
  - format: 'gid://shopify/<Type>/<id>'
    example: 'gid://shopify/Checkout/abc123'
    note: >-
      Identifiers are Shopify global IDs. They are stated explicitly for Checkout; cart, order and
      product identifiers are typed only as `string` in the schemas.
lifecycle_path: Product -> Cart -> Checkout -> Order
lifecycle_note: >-
  The path is one-way on this surface. Cart and Checkout can be cancelled; Order cannot be reversed —
  there is no refund, void or return tool. See conventions/hni-conventions.yml reversibility.