Is there a set of docs or code examples for manually authoring my own non-public provider and sets of resources in dotnet? Or is it strictly something that we have to come up with a schema for endpoints and then autogen them into a go binary?

It’s going to be possible to build a dotnet provider at some point in the future but it’s still very much in the experimental phase.

Sounds good, thanks for the reply!

It is possible to write a provider using C#, the dotnet tests run against a C# provider: https://github.com/pulumi/pulumi-dotnet/tree/main/integration_tests/testprovider But as Piers said it's currently tagged experimental. I don't expect it will change much but we might move/rename things slightly in minor releases. There's also no support for auto-generating the code from a schema, or vice-versa unlike the Go provider which will automatically build the schema from the Go code, so you need to do a lot manually.