VoltRpc

Add to your project's csproj.

<ItemGroup>
    <PackageReference Include="VoltRpc" Version="3.0.0" />
    <PackageReference Include="VoltRpc.Proxy.Generator" Version="2.1.0" />
</ItemGroup>

[GenerateProxy(GeneratedName = "TestProxy")]
public interface ITestInterface
{
  public void DoSomethingCool();
  public int GetTheCoolValue();
}

public class TestInterface : ITestInterface
{
  public void DoSomethingCool()
  {
    Console.WriteLine("Something Cool!");
  }

  public int GetTheCoolValue()
  {
    return 69;
  }
}

public class Program
{
  IPEndPoint ip = new(IPAddress.Loopback, 7767);

  TestInterface test = new();

  //Host
  Host host = new TCPHost(ip);
  host.AddService<ITestInterface>(test);
  host.StartListening().ConfigureAwait(false);

  //Client
  Client client = new TCPClient(ip);
  client.AddService<ITestInterface>();
  client.Connect();

  //Now we can call to method like it was normal C#
  TestProxy proxy = new(client);
  proxy.DoSomethingCool();
}

For a more in-depth guide, see the setup section.