ReferenceLoopHandling setting

public class Employee
{
    public string Name { get; set; }
    public Employee Manager { get; set; }
}

Employee joe = new Employee { Name = "Joe User" };
Employee mike = new Employee { Name = "Mike Manager" };
joe.Manager = mike;
mike.Manager = mike;

string json = JsonConvert.SerializeObject(joe, Formatting.Indented, new JsonSerializerSettings
{
    ReferenceLoopHandling = ReferenceLoopHandling.Ignore
});

Console.WriteLine(json);
// {
//   "Name": "Joe User",
//   "Manager": {
//     "Name": "Mike Manager"
//   }
// }