Is it possible to make calls to the proto API via something like cURL or Postman? There doesn’t seem to be an actual server running, which is a bit confusing to me.
For example, it’d be great if I could call the getCard RPC from an external program.
The Protobuf messages are mainly used for in-process communication between the Rust & Python layers, where a server would be extra overhead. An option to expose them over HTTP may come in the future, but for now I suggest you use the AnkiConnect add-on.