Best-fit companion library to Refit on the server side?

[bancroftway]

While Refit is very helpful for type-safe api client, is there a server api helper library that would complement Refit very well?

As an example, I have been looking at Fastendpoints, however, in that library, it would still require setting up the endpoint route and http verb again in the Configure method. I am really hoping that there is an elegant way to write the api Interface once in a Shared library (such as in a ASP.Net Core hosted Blazor Webassembly project), and then be able to use that api interface not only on the client side in refit but also the server.