Zend certified PHP/Magento developer

possible to use API integration to create Magento system user?

From my understanding I can create my own integration by System->extension->integration.
How do I setup the webservice and let third party to connect my Magento to create system user with user-roles account? Is there any documentation for third party how they get connect and posting request?
I only found how to create customer from google, but not the system user. I am appreciate any help or reference, so I can get it working.

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