What is Oso?
Oso
noun /ˈō-sō/ — a batteries-included system for building authorization in your application
One place for your authorization model.
Define your authorization model using Polar, a declarative policy language built for application authorization. From single-tenant roles to deep hierarchies of teams and resources, an Oso policy gives you a single place to view and change your authorization domain.
![](https://cdn.prod.website-files.com/5f148310b9588c295ed77f20/620bf862c2a8816de19c8154_Group%2018%20(1).png)
![](https://cdn.prod.website-files.com/5f148310b9588c295ed77f20/620fbe2d9ce780b1348492a1_Group%2020.png)
Comes with built-in authorization primitives.
Use any of Polar’s built-in primitives for patterns like roles, relationships and hierarchies. Or write custom rules for anything you need.
Ready to serve in the cloud, backed by open source.
Get an authorization API and fully-managed service in Oso Cloud, deployed close to your users for low-latency and backed by the open source Oso library. Or, if you have strict on-premise requirements, build using the open source Oso library on your own.