GraphQL and mobx-state-tree are match made in heaven; both are a model first oriented technologies. GraphQL optimizes data fetches and mutations. Adding mobx-state-tree to this mix, makes this model even richer: It allows client only state, actions and derived data to be mixed into our data models. We can go even further and mix in different behavior for different types of clients, while still using our GraphQL models as source of truth. Finally we can have the best of both worlds: straightforward data propagation, over the network and in the client. Leveraging the DX convenience and performance optimizations of both technologies.