MDSWS Service communicates via XML, encoded as UTF-8. The XML data must be sent as a HTTP POST request to the address of the service (XML passed as RAW_POST_DATA).

Each request must contain authorization data in the header part of the basic questions

<?xml version='1.0'?> 
  <mds>
    <auth>
    	<login>login</login>
    	<pass>your password</pass>
        <source>B2C</source>
        <srcDomain>test.mydomain.pl</srcDomain>
    </auth>
    <request>
      	... Query parameters here ...
    </request>
  </mds>

Examples of implementations can be found here