Program.cs

using cars.api.BackgroundServices;
using cars.api.Services;
using System.Reflection;

public class Program
{
    private static void Main(string[] args)
    {
        var builder = WebApplication.CreateBuilder(args);

        builder.Services.AddControllers();
        
        // Services
        builder.Services.AddSingleton<ICarService, CarService>();

        // Background Services
        builder.Services.AddSignalR();
        builder.Services.AddHostedService<RegistrationCheckService>();

        // Allow Cors
        builder.Services.AddCors(options =>
        {
            options.AddPolicy("AllowCarsApp",
                policy =>
                {
                    policy.WithOrigins("http://localhost:3000")
                          .AllowAnyHeader()
                          .AllowAnyMethod()
                          .AllowCredentials();
                });
        });

        // Register MediatR
        builder.Services.AddMediatR(cfg =>
        {
            cfg.RegisterServicesFromAssembly(typeof(Program).GetTypeInfo().Assembly);
        });

        var app = builder.Build();

        app.UseCors("AllowCarsApp");

        // Mapping
        app.MapHub<RegistrationHub>("/registrationHub");
        app.MapControllers();

        app.UseAuthorization();
        app.Run();
    }
}