authentication via external API

We are interested into take EvoStream server, in order to migrate from Wowza. We need to know if it is possible to authenticate users via an external API. We dont want to use the users file (user.xml). Currently we have implemented a TOKEN system, as example this URL rtmps://server.com/appname/streamname?token=xxxxx The Media server should check if this token is correct in order for camera to publish and for user to stream (play). Also, we want to know if you provide development services in order to develop internal plugins in the server, or if we can develop plugin by our self.