Having established the importance of the role that an app server plays when working with upstream Firebase Cloud messages, it is now time to take a look at an example server. The server outlined in this chapter will be used in the next chapter in the implementation of a simple instant messaging app designed to allow users to exchange messages.
Upstream Firebase cloud messaging requires the presence of an app server continuously connected to the Firebase CCS. The app server contains the logic that defines what happens when upstream messages are sent from client devices. This chapter has outlined the structure and basic logic of a simple app server that will be used in the next chapter to implement an example instant messaging app.