ABP Single-Layer Application Template

Docs: https://abp.io/docs/latest/solution-templates/single-layer-web-application

Solution Structure

Single project containing everything:

MyProject/
├── src/
│   └── MyProject/
│       ├── Data/              # DbContext, migrations
│       ├── Entities/          # Domain entities
│       ├── Services/          # Application services + DTOs
│       ├── Pages/             # Razor pages / Blazor components
│       └── MyProjectModule.cs
└── test/
    └── MyProject.Tests/

Key Differences from Layered

Layered Template	Single-Layer Template
DTOs in Application.Contracts	DTOs in Services folder (same project)
Repository interfaces in Domain	Use generic `IRepository<T, TKey>` directly
Separate Domain.Shared for constants	Constants in same project
Multiple module classes	Single module class

File Organization

Group related files by feature:

Services/
├── Books/
│   ├── BookAppService.cs
│   ├── BookDto.cs
│   ├── CreateBookDto.cs
│   └── IBookAppService.cs
└── Authors/
    ├── AuthorAppService.cs
    └── ...

Simplified Entity (Still keep invariants)

Single-layer templates are structurally simpler, but you may still have real business invariants.

For trivial CRUD entities, public setters can be acceptable.
For non-trivial business rules, still prefer encapsulation (private setters + methods) to prevent invalid states.

csharp

public class Book : AuditedAggregateRoot<Guid>
{
    public string Name { get; set; }  // OK for trivial CRUD only
    public decimal Price { get; set; }
}

No Custom Repository Needed

Use generic repository directly - no need to define custom interfaces:

csharp

public class BookAppService : ApplicationService
{
    private readonly IRepository<Book, Guid> _bookRepository;

    // Generic repository is sufficient for single-layer apps
}