public class LoggingInterceptor : Interceptor
{
    private readonly ILogger<LoggingInterceptor> _logger;
    public LoggingInterceptor(ILogger<LoggingInterceptor> logger) => _logger = logger;

    public override async Task<TResponse> UnaryServerHandler<TRequest, TResponse>(
        TRequest request,
        ServerCallContext context,
        UnaryServerMethod<TRequest, TResponse> continuation)
    {
        _logger.LogInformation("gRPC call: {Method}", context.Method);
        return await continuation(request, context);
    }
}

// Регистрация:
builder.Services.AddGrpc(options =>
{
    options.Interceptors.Add<LoggingInterceptor>();
});