public static void Main(string[] args)
{
    var apiVersions = new[] { "v1", "v4" }; // not ideal...I would rather grab from IApiVersionDescriptionProvider.ApiVersionDescriptions
    
    var builder = WebApplication.CreateBuilder(args);
    var services = builder.Services;
    
    // setup versioning
    services.AddEndpointsApiExplorer();
    services.AddApiVersioning(options =>
    {
        options.ReportApiVersions = true;

        options.AssumeDefaultVersionWhenUnspecified = true;
        options.ApiVersionReader = new UrlSegmentApiVersionReader();
    }).EnableApiVersionBinding();
    
    // add each ApiVersion
    foreach (var apiVersion in apiVersions)
    {
        services.AddOpenApiVersion(apiVersion);
    }

    var app = builder.Build();
    app.UseHttpsRedirection();
    app.UseForwardedHeaders(new ForwardedHeadersOptions
    {
        ForwardedHeaders = ForwardedHeaders.XForwardedProto
    });
    app.MapOpenApi();

    var health = app.NewVersionedApi("Health");

    // version 1
    var v1 = health.MapGroup("/api/health").HasApiVersion(new ApiVersion(1, 0)).WithGroupName("v1"); // group v1
    v1.MapGet("/", async () =>
    {
        var responseObject = new V1.HealthResponse
        {
            ApiMode = builder.Configuration.GetValue<string>("API_MODE") ?? "LIVE",
            Environment = builder.Environment.EnvironmentName,
            Status = "Healthy",
            TimeStamp = DateTime.UtcNow.ToString("yyyy-MM-ddTHH:mm:ss.fffffffZ", CultureInfo.InvariantCulture)
        };

        return await Task.FromResult(Results.Json(responseObject, statusCode: StatusCodes.Status200OK));
    }).Produces<V1.HealthResponse>();


    // version 4
    var v4 = health.MapGroup("/api/v{version:apiVersion}/health").HasApiVersion(new ApiVersion(4, 0)).WithGroupName("v4"); // group v4
    v4.MapGet("/", async () =>
    {
    var responseObject = new V4.HealthResponse
    {
        ApiMode = builder.Configuration.GetValue<string>("API_MODE") ?? "LIVE",
        Environment = builder.Environment.EnvironmentName,
        HealthStatus = "Healthy",
        TimeStamp = DateTime.UtcNow.ToString("yyyy-MM-ddTHH:mm:ss.fffffffZ", CultureInfo.InvariantCulture),
        TraceIdentifier = Guid.NewGuid().ToString()
    };

    return await Task.FromResult(Results.Json(responseObject, statusCode: StatusCodes.Status200OK));
    }).Produces<V4.HealthResponse>();

    app.UseSwaggerUI(options =>
    {
        // create different Swagger version pages
        foreach (var version in apiVersions)
        {
            options.SwaggerEndpoint($"/openapi/{version}.json", $"Test Api {version}");
        }
    });

    app.Run();
}

    private static void AddOpenApiVersion(this IServiceCollection services, string apiVersion) => services.AddOpenApi(apiVersion, options =>
   {
       // include group name
       options.ShouldInclude = description => description.GroupName == apiVersion;
       
       // change `v{version}` Swagger path to `vX`
       options.AddDocumentTransformer((doc, _, _) =>
       {
           var newPaths = new OpenApiPaths();

           foreach (var (key, value) in doc.Paths)
           {
               var fixedKey = key.Replace("v{version}", apiVersion);
               newPaths[fixedKey] = value;
           }

           doc.Paths = newPaths;
           return Task.CompletedTask;
       });
   });