Overview

Casbin is a powerful and efficient open-source access control library that supports various access control models for enforcing authorization across the board.

Enforcing a set of rules is as simple as listing down subjects, objects and the desired allowed action (or any other format as per your needs) in a policy file. This is synonymous across all flows Casbin is used in. The developer/administrator has the complete control over the layout, execution and conditions for authorization which is set via the model file. Casbin provides an Enforcer for validating an incoming request based on the policy and model files given to the Enforcer.

Languages supported by Casbin

Casbin provides support for various programming languages, ready to be integrated within any project and workflow:

Casbin	jCasbin	node-Casbin	PHP-Casbin
production-ready	production-ready	production-ready	production-ready

PyCasbin	Casbin.NET	Casbin-CPP	Casbin-RS
production-ready	production-ready	production-ready	production-ready

Feature set for different languages

We are always working our best to make Casbin have the same set of features for all languages. But the reality is not that beautiful.

Feature	Go	Java	Node.js	PHP	Python	C#	Delphi	Rust	C++	Lua	Dart	Elixir
Enforcement	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
RBAC	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
ABAC	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
Scaling ABAC (eval())	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅	✅	✅
Adapter	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	❌
Management API	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
RBAC API	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅
Batch API	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅	❌	❌
Filtered Adapter	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅	❌	❌
Watcher	✅	✅	✅	✅	✅	✅	✅	✅	✅	✅	❌	❌
Role Manager	✅	✅	✅	✅	✅	✅	❌	✅	✅	✅	✅	❌
Multi-Threading	✅	✅	✅	❌	✅	❌	❌	✅	❌	❌	❌	❌
'in' of matcher	✅	✅	✅	✅	✅	❌	✅	❌	❌	❌	✅	✅

Note- ✅ for Watcher or Role Manager only means having the interface in the core library. It is not indicative of whether there is a watcher or role manager implementation available.

What is Casbin?

Casbin is an authorization library which can be used in flows where we want a certain object or entity to be accessed by a specific user or subject. The type of access i.e. action can be read, write, delete or any other action as set by the developer. This is how Casbin is most widely used and its called the "standard" or classic { subject, object, action } flow.

Casbin is capable of handling many complex authorization scenarios other than the standard flow. There can be addition of roles (RBAC), attributes (ABAC) etc.

What Casbin does

1. Enforce the policy in the classic { subject, object, action } form or a customized form as you defined. Both allow and deny authorizations are supported.
2. Handle the storage of the access control model and its policy.
3. Manage the role-user mappings and role-role mappings (aka role hierarchy in RBAC).
4. Support built-in superusers like root or administrator. A superuser can do anything without explicit permissions.
5. Multiple built-in operators to support the rule matching. For example, keyMatch can map a resource key /foo/bar to the pattern /foo*.

What Casbin does NOT do

1. Authentication (aka verify username and password when a user logs in)
2. Manage the list of users or roles.

It's more convenient for the project to manage their list of users, roles or passwords. Users usually have their passwords, and Casbin is not designed as a password container. However, Casbin stores the user-role mapping for the RBAC scenario.