application.md

Application Layer

Purpose

The application layer orchestrates domain logic. It acts as the bridge between the domain (what the app knows) and the presentation layer (what the app shows). It has no knowledge of UI or external infrastructure.

Rules

• Only depends on the domain layer (entities, errors, repository interfaces).
• Must not import Flutter, HTTP, or infrastructure packages.
• Must not access data sources directly — only through domain repository interfaces.
• All operations that can fail must return Either<E, T> or TaskEither<E, T>.
• Each use case has a single responsibility (one public method per use case class).

Components

The application layer contains only use cases.

Folder Structure

application/
└── use_cases/
    ├── user/
    │   ├── get_user_use_case.dart
    │   ├── sign_in_use_case.dart
    │   └── update_user_use_case.dart
    └── orders/
        ├── get_orders_use_case.dart
        └── create_order_use_case.dart

Use cases are grouped by domain concept (matching the domain folder names). Each file contains exactly one use case class.

Detailed Docs

• Use Cases