dotnet-domain-modeling

SKILL.md

dotnet-domain-modeling

Domain-Driven Design tactical patterns in C#. Covers aggregate roots, entities, value objects, domain events, integration events, domain services, repository contract design, and the distinction between rich and anemic domain models. These patterns apply to the domain layer itself -- the pure C# model that encapsulates business rules -- independent of any persistence technology.

Out of scope: EF Core configuration and aggregate persistence mapping -- see [skill:dotnet-efcore-architecture]. Tactical EF Core usage (DbContext lifecycle, migrations, interceptors) -- see [skill:dotnet-efcore-patterns]. Input validation at API boundaries -- see [skill:dotnet-validation-patterns]. Choosing between EF Core, Dapper, and ADO.NET -- see [skill:dotnet-data-access-strategy]. Vertical slice architecture and request pipeline patterns -- see [skill:dotnet-architecture-patterns]. Messaging infrastructure and saga orchestration -- see [skill:dotnet-messaging-patterns].

Cross-references: [skill:dotnet-efcore-architecture] for aggregate persistence and repository implementation with EF Core, [skill:dotnet-efcore-patterns] for DbContext configuration and migrations, [skill:dotnet-architecture-patterns] for vertical slices and request pipeline design, [skill:dotnet-validation-patterns] for input validation patterns, [skill:dotnet-messaging-patterns] for integration event infrastructure.

Aggregate Roots and Entities

An aggregate is a cluster of domain objects treated as a single unit for data changes. The aggregate root is the entry point -- all modifications to the aggregate pass through it.

Entity Base Class

Entities have identity that persists across state changes. Use a base class to standardize identity and equality: