Websharper Proxy Project
WebSharper lets you bring your FSharp code to the client-side. For types in your WebSharper project to be used at both server and client sides, you annotate them with [<JavaScript>]. For types that were compiled without WebSharper, you need to define a proxy type, which will be compiled to javascript and be used in place of the compiled type. This is done easily, as this example from the official documentation shows: