Implementing OpenAPI 3.0 in Dart

Given an OpenAPI 3.0 spec, implement a type-safe Dart API layer with:

• Freezed (or Equatable) for models
• Dio for HTTP with interceptors and error handling
• json_serializable for JSON serialisation

Process

1. Read the OpenAPI spec — parse components/schemas for models, paths for endpoints.
2. Map schemas → Dart models (Freezed or Equatable — see Model Strategy).
3. Map paths → Dio service methods.
4. Add a repository layer that wraps the service.
5. Wire error handling via DioException → domain ApiError.

Dependencies