REST API response modelling on client side - best practices

Question

My application is integrated with some external service and makes requests to that service for data. I am just wondering what is the best practice for modelling the responses on the client side, especially in case when client business logic require only some peace of data. I am considering following implementations:

• converting JSON to class object which contains all data/properties and use such object in my code
• convertting JSON to class object which contains only those data/properties which are needed for futher processing
• combination of both above (creating class object containing all properties and than converting it to object containing only properties required for further business logic)

Answer 1

I would do the second.

converting JSON to class object which contains only those data/properties which are needed for further processing

It does not make sense to use data which is not needed. It makes only confusion. I would rather use multiple classes.