I want to dynamically include or exclude a field in a kotlin class based on certain conditions at run time before making a POST request using Retrofit and Gson, anyone has ideas on how to achieve this dynamically? I've tried using the expose annotation but it can't accept run time variables.

Make it nullable and configure type converter (somehow) to not serialize null fields maybe?

@wasyl i have a couple of instances where i may want to send null fields to the backend.

You could try with a wrapper type then, something like

Optional<T?>?

, and have a custom type adapter for it

@wasyl would be a good solution, the only problem is that this only works on min API level 24 and i'm working on 22

Then create your own wrapper 🤷‍♂️