Simulating earthquakes to evaluate the risks is an important task in geophysics. The behavior of seismic waves depends on the rupture of a fault and the material they are going through. Therefore, we need to know the initial spatially-dependent material of an area and the initial fault parameters. Based on this idea, the library easi offers the opportunity to initialize models. Easi uses .yaml files as models, which can replace thousands lines of manual model-specific Fortran code. However, it is still very easy to make a mistake and the more realistic the models are, the more complicated they become. To overcome this problem, a node-based interface called easi-gui has been implemented, respecting the syntax described by easi. It opens and saves the .yaml files used by easi for the user, that only needs to interact with nodes.