is group's unique id remains unique across multiple domains

Question

We are using Google Directory API to access Domain Groups of multiple Domains. Id of the group is supposed to be unique for a domain. I am wondering if it is also unique across multiple domain. We are thinking to save information of groups in database with unique constraints on unique id

Answer 1

The group id should be unique across multiple domains.

For example, when you do the GET request to retrieve a group, you only need to supply a group id:

GET https://www.googleapis.com/admin/directory/v1/groups/YOUR_GROUP_ID

No domain name is required to retrieve a group (Same for UPDATE or DELTE a group).

Also be aware not to use email address of a group as a unique ID since email address can be subject to change.

You can visit this section in Directory API for more information about the group.