public class Query : GraphQLObjectType
{
	public Query() : base("Query", "Root query defintion")
	{
		this.Field("sum", (int[] numbers) => numbers.Sum());
	}
}

public class MyAwesomeSchema : GraphQLSchema
{
    public MyAwesomeSchema()
    {
        var rootQuery = new Query();
        this.AddKnownType(rootQuery);
        this.Query(rootQuery);
    }
}

[Route("api/[controller]")]
public class GraphQLController : Controller
{
    private MyAwesomeSchema schema = new MyAwesomeSchema();

    [HttpPost]
    public JsonResult Post(string query)
    {
        return this.Json(
            new
            {
                data = this.schema.Execute(query)
            }
        );
    }
}