Does references in application layer to mediatr and fluent validation break the clean architecture principles?

[VadimGaskov]

Shouldn't all references to external libraries be in the infrastructure layer, implementing the application layer's interfaces?

[DennisJansenDev]

No.

[VadimGaskov]

can you explain?

[jasontaylordev]

Using MediatR and FluentValidation in the Application layer is a common and accepted practice. The Application layer defines use cases and coordination logic, and these libraries help with that. They are not infrastructure concerns, so it's fine for the Application layer to reference them directly.