HI Kourosh,

A MID Server is only necessary if you are trying to access resources that are not available to the ServiceNow instance. If your web service endpoints are available from the Internet then you can consume them from your ServiceNow instance directly.

You do not need a MID server to access your instance either. You will generally need to authenticate, but you can create APIs that are fully public if you have a use case.

You would typically only need a MID Server when you would like your ServiceNow instance to initiate communication with a device that would normally not be available due to firewall restrictions.