Modern software systems should be more and more designed with adaptation and run-time evolution in mind. But even with good reactions to changes, the triggered adaptation should be performed preserving some properties that we call invariants. This position paper presents a step towards the definition of a theoretical assume-guarantee framework that allows one to efficiently define under which conditions adaptation can be performed by still preserving the desired invariant. The framework aims to cope with different levels of granularity that span from code to software architecture. Two illustrative examples instantiate the framework at two different levels of abstraction.