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Domain Package

The Domain package contains the essential business logic and core entities of the application.

domain/
├── model/         immutable domain entities
│   ├── User.kt, AuthProvider.kt, Subscription.kt, ExampleModel.kt
│   ├── credit/        CreditSystemConfig.kt, CreditTransaction.kt, RecurringCredit.kt, …
│   └── generation/    GenerationInput.kt, GenerationOutput.kt, GenerationParam.kt, …
├── exceptions/    domain-specific exceptions
└── usecase/       use cases, added only when orchestration is justified

model​

Immutable data classes representing core business entities:

  • User — a user, with properties like id, email, and hasPremiumAccess.
  • AuthProvider — enum of authentication methods (e.g. GOOGLE, APPLE).
  • Subscription — subscription information and access levels.
  • GenerationInput / GenerationOutput — the AI generation workflow.
  • CreditTransaction / CreditSystemConfig — the credit system (balance, transactions, configuration).

exceptions​

Domain-specific exceptions for known error scenarios:

  • UnAuthorizedException — the user tried to perform an operation while logged out. Catch it in your ViewModel and navigate to the sign-in screen — see ProfileViewModel for an example.
  • PurchaseRequiredException — the operation requires a premium subscription the user doesn't have.
  • CreditRequiredException — the operation requires more credits than the user's balance.
  • UserAlreadyExistsException — attempted to create a user that already exists.