Architecture

flowchart TB
    subgraph Catalog["Catalog"]
        Product --> Variant
        Variant --> Price
        Variant --> StockItem
        StockItem --> StockLocation
    end

    subgraph Shopping["Shopping"]
        User --> Order
        Order --> LineItem
        LineItem --> Variant
    end

    subgraph Checkout["Checkout"]
        Order --> Address
        Order --> Shipment
        Order --> Payment
        Shipment --> ShippingMethod
        Payment --> PaymentMethod
    end

    subgraph Fulfillment["Fulfillment"]
        Shipment --> InventoryUnit
        InventoryUnit --> Variant
        StockLocation --> Shipment
    end

    subgraph Pricing["Pricing & Adjustments"]
        Order --> Adjustment
        LineItem --> Adjustment
        Shipment --> Adjustment
        TaxRate --> Adjustment
        Promotion --> Adjustment
    end

erDiagram
    Store ||--o{ Order : "has many"
    Store ||--o{ Product : "has many"

    Product ||--o{ Variant : "has many"
    Product }o--|| TaxCategory : "belongs to"
    Product }o--|| ShippingCategory : "belongs to"
    Product }o--o{ Taxon : "categorized by"

    Variant ||--o{ Price : "has many"
    Variant ||--o{ StockItem : "has many"
    Variant ||--o{ LineItem : "has many"

    Order ||--o{ LineItem : "has many"
    Order ||--o{ Shipment : "has many"
    Order ||--o{ Payment : "has many"
    Order ||--o{ Adjustment : "has many"
    Order }o--|| User : "belongs to"
    Order }o--|| Address : "ship address"
    Order }o--|| Address : "bill address"

    Shipment ||--o{ InventoryUnit : "has many"
    Shipment }o--|| StockLocation : "ships from"
    Shipment }o--|| ShippingMethod : "via"

    Payment }o--|| PaymentMethod : "via"

    StockLocation ||--o{ StockItem : "has many"

    TaxRate }o--|| TaxCategory : "belongs to"
    TaxRate }o--|| Zone : "applies to"
    TaxRate ||--o{ Adjustment : "creates"

    Promotion ||--o{ Adjustment : "creates"