Use Workspace for identity and groups for access
Workspace confirms who the user is. A Google group answers whether that person should open a specific tool. The app itself does not need a user table or a role editor.
Google Workspace administrators can manage group membership and group access settings from the Admin console. Google documents those controls in its Groups administration guide.
Validate the identity response
Check the token issuer, audience, expiry and signature. Use Google’s stable subject identifier for the account. An email address alone does not prove that Google issued the session for your application.
The hosted-domain claim can help identify the Workspace tenant, but the access decision still belongs to the group or policy assigned to the tool.
Choose groups that match real responsibilities
Share a finance reconciliation tool with the finance operations group. Share a support dashboard with the support leads group. Avoid creating a new group for each test app if an existing team group already has the right membership.
Handle contractors and individual access
Put recurring access in a group. Give individual access an expiry date. This keeps the permanent access model legible while still covering a short review or external project.
Record who approved the exception and when it ends. Once the date passes, remove the individual grant instead of converting it into permanent access by accident.
Make offboarding automatic
Put the access check in front of every tool. Suspending a Workspace account then closes the same person’s access across the registry. Tool owners do not need to remove the account from separate databases.
Audit access from the tool registry
Directory groups tell you who belongs to a team. The tool registry should tell you which groups can open each app. Keep both sides visible so an administrator can start with a person, a group or a tool and reach the same answer.
Export the mapping for periodic review. Flag tools with no owner, individual grants that reached their expiry date and apps that have not been used for the period your company defines.