//Add a request filter to check if the user has a session initialized
this.RequestFilters.Add((httpReq, httpResp, requestDto) => {
    var sessionId = httpReq.GetCookieValue("user-session");
    if (sessionId == null)
    {
        httpResp.ReturnAuthRequired();
    }
});

//Add a response filter to add a 'Content-Disposition' header so browsers treat it as a native .csv file
this.ResponseFilters.Add((req, res, dto) => {
    if (req.ResponseContentType == ContentType.Csv)
    {
        res.AddHeader(HttpHeaders.ContentDisposition,
            string.Format("attachment;filename={0}.csv", req.OperationName));
    }
});