To override the Content-type in your clients, use the HTTP Accept Header, append  the .csv suffix or  ?format=csv
        
        HTTP + CSV
         The following are sample HTTP requests and responses. 
            The placeholders shown need to be replaced with actual values.
POST /csv/reply/GetUsersAndGroups HTTP/1.1 
Host: doapigw.baasbv.nl 
Accept: text/csv
Content-Type: text/csv
Content-Length: length
{"UserEnvironment":0,"PageSize":0,"PageNumber":0,"SearchCriteria":"String","SelectedUserIDs":[0],"SelectedGroupIDs":[0]}
 
HTTP/1.1 200 OK
Content-Type: text/csv
Content-Length: length
{"NumberOfAllRecords":0,"UsersOrGroups":[{}],"QuickAddOptions":[{"Name":"String","EntityType":"String"}]}