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Generics & Mixins: Flexible ViewSet Architecture in FastAPI Ronin

FastAPI Ronin's architecture leverages generics and mixins to create flexible, reusable ViewSet components. This modular design enables you to build powerful and customizable APIs by composing specific functionalities tailored to your application’s needs.

Architecture Overview

FastAPI Ronin uses a layered architecture:

ModelViewSet / ReadOnlyViewSet
        ↓
    GenericViewSet (core functionality)
        ↓
    Mixins (add specific routes)

GenericViewSet - The Foundation

GenericViewSet contains all the core business logic:

  • Schema handling - Converting between models and Pydantic schemas
  • Permission checking - Applying access control
  • State management - Managing request context
  • Response formatting - Applying wrappers and pagination

Mixins - Route Providers

Mixins only add specific routes to the GenericViewSet. They contain no business logic:

  • ListMixin - Adds GET /resources/ endpoint
  • RetrieveMixin - Adds GET /resources/{item_id}/ endpoint
  • CreateMixin - Adds POST /resources/ endpoint
  • UpdateMixin - Adds PUT /resources/{item_id}/ endpoint
  • DestroyMixin - Adds DELETE /resources/{item_id}/ endpoint