c # – API, reuse models or

We have many API services (C # Web-API, not REST) ​​and each of them has its own separate logic and separate request and response models. Some of these models (you can call them DTO or Domain Class) can be merged or unified.

The question is: What is preferable?

  • To keep them apart due to future releases
  • Merge them by inheritance
  • To use them twice
  • or use a design pattern

But please give reasons or pros, cons too …