Client Plan From Master

[KA]

I have plan A(Master) and Plan B (Client) How can i pass variables from plan A to plan B as which branch to executed and from client plan B send the artifacts to Plan A . 

If anyone has done this kind of use case do let me know.

I am able to trigger plan B from Plan A  by calling service from shell script, But if there is way i can share variable back and forth that will be helpful