Casbin is a powerful and efficient open-source access control library for Go. It provides support for enforcing authorization based on various models. So far, the access control models supported by Casbin are:

• ACL (Access Control List)
• ACL with superuser
• ACL without users: especially useful for systems that don’t have authentication or user log-ins.
• ACL without resources: some scenarios may target for a type of resources instead of an individual resource by using permissions like write-article, read-log. It doesn’t control the access to a specific article or log.
• RBAC (Role-Based Access Control)
• RBAC with resource roles: both users and resources can have roles (or groups) at the same time.
• RBAC with domains/tenants: users can have different role sets for different domains/tenants.
• ABAC (Attribute-Based Access Control)
• RESTful
• Deny-override: both allow and deny authorizations are supported, deny overrides the allow.