well, it won't be just a simple GET /user/1 anymore. it will be like: user { id name role status age sex address group { id name } etc etc }

Right - what I meant was more like when you get some data you probably want to display it in the UI and would already be doing something like ‘Hi ${user.name}, your age is ${user.age}’. This is affected by schema changes irrespective of the way the API is invoked.