Is there a recommended approach to sharing a SignalR hub across two applications?
The actual situation is a public facing WebAPI project and an internal MVC WebApp.
Just setup signalr message routing through a SQL Server table. It will automatically connect all hubs using the same routing setup. Nothing else to do, it's magic.
GlobalHost.DependencyResolver.UseSqlServer(ConfigurationManager.ConnectionStrings["signalr"].ConnectionString);
You will need the following nuget package: Microsoft.AspNet.SignalR.SqlServer