WebSharper.Forms is a client-side library for building reactive forms in a functional, composable and type-safe manner. It enables developers to represent their UIs as an abstract declarative specification, and to give a concrete UI instantiation/rendering over it as their applications see fit. In this talk, I will build a simple shopping cart application that demonstrates the power of the combination of abstract forms, WebSharper’s type-safe templating, and reactive two-way data binding. The resulting application will be 100% type-safe F# code, tiny compared to JavaScript-based alternatives, and a whole lot of fun to write.