Concepts

Concepts are formalized value types that wrap a primitive. They give every domain value a precise, strongly-typed name — you never pass a raw Uuid or String around — and they are where compliance is declared. Attributes control compliance behavior: Chronicle applies @pii and @sensitive rules automatically wherever the concept is used.

Syntax

concept <Name> : <PrimitiveType> [<attributes>]

concept <Name> : Enum
  <value>+

Primitive types

Uuid, String, Int, Decimal, Bool, Date, DateTime

Attributes

Attribute	Meaning
@pii	The value is personally identifiable information. Chronicle manages it and can erase it for GDPR compliance.
@sensitive	The value is sensitive and handled under Chronicle’s sensitivity rules.

Examples

concept InvoiceId        : Uuid
concept EmailAddress     : String   @pii
concept NationalIdNumber : String   @pii @sensitive
concept DateOfBirth      : Date     @pii

Enum concepts

An enum concept declares a fixed set of values as an indented list:

concept InvoiceStatus : Enum
  draft
  sent
  paid
  overdue
  cancelled

concept PaymentTerms : Enum
  net30
  net60
  immediate

Attribute inheritance

When a concept is used as a property type on a command or event, its attributes are inherited — you never annotate at the property level. Declaring EmailAddress as @pii once means every event property, command property, and read model field typed as EmailAddress is treated as PII automatically.