riddl-models/
├── patterns/           # Reusable DDD/Reactive patterns
├── technology/         # SaaS, DevOps, Platform services
├── investment/         # VC, Private Equity, Asset Management
├── finance/            # Banking, Payments, Trading
├── insurance/          # P&C, Life, Reinsurance
├── commerce/           # E-commerce, Retail, Marketplace
├── hospitality/        # Hotels, Restaurants, Travel
├── entertainment/      # Media, Gaming, Sports
├── marketing/          # Campaigns, Advertising, Analytics
├── healthcare/         # Clinical, Pharmacy, Payer
├── manufacturing/      # Discrete, Process, Maintenance
├── construction/       # Projects, Real Estate
├── engineering/        # PLM, Consulting
├── transportation/     # Freight, Passenger, Fleet
├── logistics/          # Warehousing, Fulfillment
├── natural-resources/  # Mining, Oil & Gas, Agriculture
├── utilities/          # Electric, Gas, Water
├── telecommunications/ # Network, Billing
├── government/         # Citizen Services, Public Safety
├── education/          # Academic, Training
└── professional-services/ # Legal, Accounting, HR

// From commerce/e-commerce/shopping-cart/

domain ECommerce is {
  context ShoppingCart is {
    entity Cart is {
      briefly "Customer's shopping cart"

      type CartId is Id(Cart)
      type CartItem is { productId: ProductId, quantity: Integer, price: Decimal }

      command AddItem is { cartId: CartId, item: CartItem }
      command RemoveItem is { cartId: CartId, productId: ProductId }
      command Checkout is { cartId: CartId }

      event ItemAdded is { cartId: CartId, item: CartItem }
      event ItemRemoved is { cartId: CartId, productId: ProductId }
      event CartCheckedOut is { cartId: CartId, total: Decimal }

      state Active is {
        id: CartId,
        items: CartItem*,
        total: Decimal
      }

      handler CartHandler is {
        on command AddItem {
          set field items to state.items + @AddItem.item
          send event ItemAdded to outlet Events
        }
        on command Checkout {
          send event CartCheckedOut to outlet Events
        }
      }
    }
  }
}