Membership in Sentry is handled at the organizational level. The system is designed so each user has a singular account which can be reused across multiple organizations (even those using SSO). Each user of Sentry should have their own account, and will then be able to set their own personal preferences in addition to receiving notifications for events.
Access to organizations is dictated by roles. Your role is scoped to an entire organization. Roles include:
The owner has full access to all controls within an organization.
The manager is similar to the owner, except that they cannot remove the organization.
An admin has full access to all projects they’re a member of, but will not be able to add or change members in the organization.
A member can only view and act on issues, such as assigning and resolving.