using System;

using System.Net.Http;

using System.Net.Http.Headers;

using System.Text;

using System.Threading.Tasks;

using System.Text.Json;

public record NewAssociateEvent(int AssociateId);

​

public class Program

{

    public static void Main()

    {

        var model = new NewAssociateEvent(99);

        string serialized = System.Text.Json.JsonSerializer.Serialize(model);

        NewAssociateEvent deserialized = JsonSerializer.Deserialize<NewAssociateEvent>(serialized);

        Console.WriteLine(serialized);

        Console.WriteLine(deserialized);

    }

}