Management of Agent and User in Nexus

From nexus-kg created by [samuel-kerrien](https://github.com/samuel-kerrien) : BlueBrain/nexus-kg#346

This thread of email was originally exchanged by Jean Denis Courcol and Francois Sy:

Dear All,

I would like to understand better your strategy with respect to user and
agent identification in Nexus (at least in the BBP context).

Let 's say a experimenter (let's say Ying) has created some morphology
reconstructions. How is that agent representing Ying created in Nexus ?
What information are provided ? Who is providing these information ? How
is it uniquely identified (gaspar id, e-mail ...) ?

Let's say a user performs some analysis through one of our software
(let's say Ying or Lida). How do we query the system to know if that
agent is already in the system: How is the agent identified ? Keep in
mind that the only user identification element we have on the software
side is the authentication token.

If the agent is not in the system, how is it going to be created ?

Regards,

Jean-Denis