// To use NewtonsoftJsonSerializer, add a reference to NuGet package GraphQL.Client.Serializer.Newtonsoft
var graphQLClient = new GraphQLHttpClient("https://api.example.com/graphql", new NewtonsoftJsonSerializer());

var heroRequest = new GraphQLRequest {
    Query = @"
    {
        hero {
            name
        }
    }"
};

var personAndFilmsRequest = new GraphQLRequest {
    Query =@"
    query PersonAndFilms($id: ID) {
        person(id: $id) {
            name
            filmConnection {
                films {
                    title
                }
            }
        }
    }",
    OperationName = "PersonAndFilms",
    Variables = new {
        id = "cGVvcGxlOjE="
    }
};

public class ResponseType 
{
    public PersonType Person { get; set; }
}

public class PersonType 
{
    public string Name { get; set; }
    public FilmConnectionType FilmConnection { get; set; }    
}

public class FilmConnectionType {
    public List<FilmContentType> Films { get; set; }    
}

public class FilmContentType {
    public string Title { get; set; }
}

var graphQLResponse = await graphQLClient.SendQueryAsync<ResponseType>(personAndFilmsRequest);

var personName = graphQLResponse.Data.Person.Name;

var graphQLResponse = await graphQLClient.SendQueryAsync(personAndFilmsRequest, () => new { person = new PersonType()} );
var personName = graphQLResponse.Data.person.Name;

public class UserJoinedSubscriptionResult {
    public ChatUser UserJoined { get; set; }

    public class ChatUser {
        public string DisplayName { get; set; }
        public string Id { get; set; }
    }
}

var userJoinedRequest = new GraphQLRequest {
    Query = @"
    subscription {
        userJoined{
            displayName
            id
        }
    }"
};

IObservable<GraphQLResponse<UserJoinedSubscriptionResult>> subscriptionStream 
    = client.CreateSubscriptionStream<UserJoinedSubscriptionResult>(userJoinedRequest);

var subscription = subscriptionStream.Subscribe(response => 
    {
        Console.WriteLine($"user '{response.Data.UserJoined.DisplayName}' joined")
    });

subscription.Dispose();