Enumerations

model/enum.yml

enumeration:
  OrderStatus:
    meta: enum @db(code) @json(code) -- order status
    fields:
      code:  string(3) @code
      label: string(20)
    enum:
      PLACED:    PLC, Placed
      SHIPPED:   SHP, Shipped
      CANCELLED: CAN, Cancelled

Annotation	Means
@db(field)	the field stored in the database
@json(field)	the field sent in JSON
@code (on a field)	stored and sent - @db and @json at once

Each constant lists its field values in order (PLC, Placed). The database holds PLC, the JSON says "PLC", and the generated TypeScript has both the codes and the labels (OrderStatusLabel).

• Lifecycles use the constant names, not the codes: ship: PLACED -> SHIPPED. See Lifecycle.
• Metrics compare with constant names too (where status != CANCELLED); the export turns them into the stored value ('CAN'). See Metrics.
• An unknown code in a request answers 400 with a field error (Unknown CreditCardType code: DINERS).
• Spring Boot 4: enums are generated with @JsonValue + @JsonCreator, which Jackson 3 reads; see Spring Boot 3 and 4.
• In the Ossie export an enum field is datatype: String with ai_context: "Codes: PLC = Placed, SHP = Shipped, CAN = Cancelled".