BiTE's architecture is modelled after the model-view-presenter pattern. The bash interpreter and the underlying thread that runs external programs form the model. The X11 GUI is the view, and the session is the presenter.
All communication from and to the user is performed by the GUI. This corresponds to the view component.
Events are propagated to a separate group of presenter classes, one for each type of interaction. Events are converted in the view to the appropriate method calls of the presenters. The presenters query and update the model.
The model is comprised mainly of the session and the bash interpreter. Together they form the interactive shell.
The bash interpreter is a complete reimplementation of bash in rust. After startup, the interpreter operates in a separate thread that is controlled by a front-end to care of the communication between front-end and back-end. This allows the back-end to block while the main GUI thread (the front-end) continues to run.