title: Google App Script: Sharing and publishing different versions of the script across different domain accounts
body: <p>How do you share a Google App Script across several different domain accounts? (note: these are separate customers with their own domain accounts)</p>
  
  <p>Only the script owner can publish a script, therefore sharing the source script requires the respective domain admin user to make a copy of the script.  This of-course generates a different script ID.</p>
  
  <p>Opening this copy-of-the-script means that I have no other managed versions of the script.  If I create a new "Managed Version" and follow the instructions for provisioning the Add-On I end up with a separate publishing project, with separate OAuth credentials, etc.</p>
  
  <p>This results in new clientId+clientSecret for each released version of the script.  The "Managed Versions" option only seems to handle edits of the script from within the domain account the script copy resides.  </p>
  
  <p>How can I manage version control of my app script when I'm forced to create [a new app script + publish project + OAuth credentials] every time I need to make a change to the code?    This way, every publishing project has just one managed version of the app script.  </p>
  
  <p>How does everyone else manage code changes across entirely separate domain accounts?</p>