Hi @Joris and so sorry for the delay in getting back to you!
So if I’m getting you right, you need to have your developer and your clients in the same project. Developers must be able to create tasks in this project and your clients must be able to see these tasks, but customer and developers can’t see each other, is that correct?
Can you confirm if your customers need access to tasks where your developers are working?
Looking forward to your reply!
Hello
You are almost right 
Client & developper should be able to create task, and both of them shouldn’t be able to see each other (to avoid contact)
Can you confirm if your customers need access to tasks where your developers are working?
Well i confirm, execpt if you suggest me another way ?
Because i have try created to different team, one for client only, and one for dev team BUT i must copy paste each time all task on both team 
Thx for help
Thanks @Joris,
Unfortunately, if your client need to see tasks where developers are working, they will automatically see your developers name; I’m afraid there is no good workaround this!
The multiihome would save you from having to copy information from one project to the other, but it will also allow your client and developer to see each other, so that’s not an option here! So sorry for not being able to help you further with this; what I can do is convert this thread into a product feedback thread to allow other users to vote for this feature request to be considered by our team; let me know if that suits in the meantime!
Thx for help.
Why not we can suggest as idea but i don’t think a lot of user require this type of feature 
I already ended up in the situation where I was in a client’s space and my “colleague” appeared as a “private user” I could not see. I think it was because we were not part of the team of the project member. Can you confirm?
Actually… great point @Bastien_Siebman!!
@Joris, can you confirm your developers and clients are Guests of your Organization (as in they don’t share the same email domain than you)?
If so, here is something that might work:
Create two teams (Team A for your dev, Team B for your clients)
In Team A create project A and add your dev to this project
In Team B create project B and add your clients to this project
Multihome all tasks of Project A into Project B
As a result, your dev and clients will have access to the same tasks, but because they don’t belong to the same team or the same project, they won’t be able to see each other name, and will appear as private users.
Have a look at this other thread when users ended in this situation without trying to in the first place 
"Private user" for collaborators/Assignee - #5 by Bastien_Siebman
@Marie thx.
What do you call guest ? i don’t think they are since i am invited everyone to be part of a team
E.g : Team A: i have invite my dev & client, so they are not guest.
I don’t really understand this “guest” criteria.
Anyway if i can make them as guest (i think easy for client) i will, but please tell me how.
Then, i have to check what is Multihome since i don’t know whats that
Thx
Here is the definition of a Guest in Asana: Working with guests in an organization • Asana Product Guide
Essentially every user that does not use your organisation domain is considered as a Guest in Asana!
@Marie Oh, i think i get it, but i have to check so where i configure my domain… cause uintil now, only me is using mail@mycompany.fr … all other members (dev & clients) are using their own emails
And again @Joris there is nothing better than a good old test, so don’t hesitate to create two accounts for yourself and test.
As long as your clients and dev don’t use an @mycompany.fr email address, you should be all good to go!
By the way, our Community Forum is also available in French In fact both @Bastien_Siebman and I are native French speakers, so if you’d like to get help or share yoru experience with Asana in French, feel free to post in Forum de la Communauté French - Asana Community Forum!
But don’t put them as Team members or Project members, because if you do they will see each other. Correct @Marie?
@Bastien_Siebman indeed. I just made a screen share with one developer and i notice that he is able to see every members.
So my question now is how i can give acess to a project or task to someone without beeing a team member or project member ? Just by giving URL link ?!
I am confused there.
I have just test to give link to one asana user outside of any project or team member.
When he click on the link he got this error
Based on this i don’t understand how a user can have access to task or project without beeing a team member
You can add them as collaborators of the task only. They will see the task(s) but not the rest.
Sorry for late reply.
I’m a bit lost, ill go create a post in french forum so
