HPSM 9.21 WEBSERVICE

Hi...

We're using HPSM 9.21 and planning to use Webservices between HPSM and other tool called Service Now.

My question is: Is possible to create an full integration using only by webservices from HPSM between this applications? For example: HPSM creating/updating a ticket or RFC and replicate to ServiceNow or.... ServiceNow creating the same information and replicate to HPSM too.

Or always I needs to use Connect-It?

Best Regards!