OwinMiddlwareClass

CustomMiddleware.cs

public class CustomMiddleware : OwinMiddleware
{
    public CustomMiddleware(OwinMiddleware next) : base(next)
    {
    }

    public async override Task Invoke(IOwinContext context)
    {
        context.Response.Headers["MachineName"] = Environment.MachineName;

        await Next.Invoke(context);
    }
}