Users management
Your Management → Users view breaks down all of your users across all accounts. If users are assigned to more than one application, you will be able to see all of the applications they can use in the Application column.
When creating a new user and inviting them to a specific account, you can choose from the drop-down Applications field which applications the user can access as part of their login. If the account you invite the user to has applications that were set as auto-assigned, then those will be assigned to the user automatically. Note that users cannot be invited to applications which haven't been assigned to their accounts first. You can add more applications according to what's available in the account to which you invite the user.
Applications API reference
Applications API reference
You can perform multiple actions like assigning users to multiple applications via our Applications API collection.
User roles for specific apps
User roles for specific apps
Roles are not application specific. Still, you can create roles with specific Permissions in a way that they would contain permissions required in specific applications only, and then assign the users in that account to that specific role.