Bootstrapper.cs

protected override void RequestStartup(ILifetimeScope container, IPipelines pipelines, NancyContext context)
{
    pipelines.AfterRequest.AddItemToEndOfPipeline(ctx =>
    {
        if (ctx.Response.StatusCode != HttpStatusCode.InternalServerError)
        {
            container.Resolve<DbContext>().SaveChanges();
        }
    });
}