generated: '2026-08-26'
method: derived
source: >-
  mcp/prime-hydration-mcp-tools.json - the verbatim tools/list response from
  https://drinkprime.com/api/ucp/mcp (HTTP 200, 2026-08-26). Entities and relationships are read
  from the 13 tool inputSchemas and their identifier formats. There is no OpenAPI to derive
  from; this is the only structured contract Prime Hydration publishes.
note: >-
  Shapes are named after the UCP shopping capabilities the merchant profile declares
  (dev.ucp.shopping.catalog, .cart, .checkout, .fulfillment, .discount, .order). Fields not
  visible in the request schemas are not invented here - response schemas are not published in
  tools/list, so this graph is the request-side and identifier-side view only.
identifier_scheme:
  format: Shopify Global ID (GID) URN
  pattern: 'gid://shopify/{Type}/{id}'
  observed:
  - 'gid://shopify/Checkout/abc123'
  - 'gid://shopify/Cart/abc123'
  opaque: true
  agent_rule: Server-issued; never construct or mutate.
money_type:
  name: Money
  fields:
  - name: amount
    type: integer
    note: Minor units of the currency (600 == $6.00 in USD).
  - name: currency
    type: string
    note: ISO 4217 code.
entities:
- name: Product
  capability: dev.ucp.shopping.catalog
  accessed_by: [search_catalog, lookup_catalog, get_product]
  identified_by: product identifier (GID or handle)
  note: >-
    Also readable without MCP at GET /products/{handle}.json and GET /products.json on the
    storefront.
- name: Variant
  capability: dev.ucp.shopping.catalog
  accessed_by: [lookup_catalog, get_product]
  identified_by: variant identifier
  note: lookup_catalog accepts "products or variants by identifier".
- name: Cart
  capability: dev.ucp.shopping.cart
  accessed_by: [create_cart, get_cart, update_cart, cancel_cart]
  identified_by: 'gid://shopify/Cart/{id}'
- name: Checkout
  capability: dev.ucp.shopping.checkout
  accessed_by: [create_checkout, get_checkout, update_checkout, complete_checkout, cancel_checkout]
  identified_by: 'gid://shopify/Checkout/{id}'
  note: Carries line items, totals, discounts, taxes, payment and fulfillment selections.
- name: LineItem
  capability: dev.ucp.shopping.cart
  accessed_by: [create_cart, update_cart, create_checkout, update_checkout]
  identified_by: variant reference + quantity
- name: Order
  capability: dev.ucp.shopping.order
  accessed_by: [get_order, complete_checkout]
  identified_by: order ID returned by complete_checkout
- name: Discount
  capability: dev.ucp.shopping.discount
  accessed_by: [get_checkout, update_checkout]
  note: >-
    Declared as a capability in /.well-known/ucp; surfaces as applicable discounts on the
    checkout rather than as a standalone tool.
- name: Fulfillment
  capability: dev.ucp.shopping.fulfillment
  accessed_by: [update_checkout]
  config_from_ucp_profile:
    allows_multi_destination.shipping: false
    allows_method_combinations: [[shipping]]
  note: >-
    Read verbatim from /.well-known/ucp - this store ships to ONE destination per checkout and
    supports only the "shipping" method combination. A material constraint an agent must respect
    when splitting a buyer's basket.
- name: PaymentHandler
  capability: payment_handlers
  accessed_by: [complete_checkout]
  instances:
  - id: gpay
    handler: com.google.pay
    version: '2026-01-11'
    card_networks: [VISA, MASTERCARD, AMEX, DISCOVER]
    billing_address_required: true
  - id: shopify.card
    handler: dev.shopify.card
    version: '2026-01-15'
    card_brands: [visa, master, american_express, discover, diners_club]
  - id: shop_pay
    handler: dev.shopify.shop_pay
    version: '2026-04-08'
  note: >-
    Read verbatim from /.well-known/ucp payment_handlers. Card data is handled by these
    handlers, not by Prime Hydration's agent surface.
- name: AgentProfile
  capability: ucp discovery
  accessed_by: all 13 tools
  identified_by: meta.ucp-agent.profile (URI)
  note: Caller-asserted, unverified. Identity metadata, not a credential.
- name: Customer
  capability: shopify customer accounts
  accessed_by: OAuth 2.0 / OIDC at orders.drinkprime.com (not exposed through this MCP endpoint)
  note: See authentication/ and scopes/. A probe of the customer-account MCP surface 404d anonymously.
relationships:
- from: Cart
  to: LineItem
  type: has_many
  via: cart.line_items
- from: LineItem
  to: Variant
  type: belongs_to
  via: variant identifier
- from: Variant
  to: Product
  type: belongs_to
  via: product identifier
- from: Checkout
  to: Cart
  type: belongs_to
  via: cart id supplied to create_checkout
- from: Checkout
  to: LineItem
  type: has_many
  via: checkout.line_items
- from: Checkout
  to: Discount
  type: has_many
  via: applicable discounts on the checkout
- from: Checkout
  to: Fulfillment
  type: has_one
  via: shipping address + method set by update_checkout
- from: Checkout
  to: PaymentHandler
  type: has_one
  via: checkout.payment supplied to complete_checkout
- from: Order
  to: Checkout
  type: belongs_to
  via: order ID returned by complete_checkout
- from: Order
  to: Customer
  type: belongs_to
  via: buyer identity captured at checkout
gaps:
  response_schemas: >-
    tools/list publishes inputSchema only. Response shapes are described in prose in the tool
    descriptions and formally only in the ucp.dev capability schemas
    (https://ucp.dev/2026-04-08/schemas/shopping/*.json), which are the standard's, not the
    provider's.