with the freedom to extend, shape, and tweak as you need

For teams that are past rolling their own authorization

A Library

Get started fast

Pull Oso from your favorite package manager, add it to your application, and you are ready to start enforcing authorization over API requests, data fetches, and UI components.
Learn about the library

Stand on the shoulders of giants

You don't have to reinvent how to model roles and relationships, or how to architect your system. We give you the mental model and best practices and make them available via APIs, helper methods and guides.
Learn about our APIs
A Policy Language

Add permissions features and stay future-proof

Write your own policies to reflect the nuances of your use case. Be confident that you are in control and can customize anything you need because Oso is backed by a declarative policy language.
Explore the Oso Policy Language
Authorization Academy

Learn authorization best practices

Read a series of technical guides that explains how to build authorization into an app, including architecture, modeling patterns, enforcement, and more — whether you use Oso or not.
Browse the Guides

Loved by Developers

Calvin French-Owen
Founder, Segment

“We spent 6+ months building authz infra. Oso is ensuring other companies get the right building blocks from day one."

Patrick O'Doherty
Sr. Engineer, Intercom

“Oso is an example of high quality of life software. I nearly wept when I realized I could just reuse our existing relationships as-is."

KC Chintalapati
Engineer, Fiddler

“Oso was the fastest path to building roles and has been incredible – easy to wrap our heads around, great docs, and makes life much simpler."

Karan Talati
CEO, First Resonance

“We love Oso because it lets us manage the chaos of access. We got up to speed in 1 week and into production in 3 weeks with 1 engineer.”

Gaurub Pandey
CTO, Dhi

“Oso is awesome. It has made it much easier to express anything we need in our EHR application. It sped up our authZ roadmap 4x."

Simen A. W. Olsen
CDO, Bjerk

“We love Oso, and that's not just because their authorization library is the best, but because the team is awesome too!"

William Hayes
CSO, BioDati

“Brilliant engineering. Helps guide one through what seems like a simple thing but never is."

Mike Dearman
Engineer, Undisclosed

“I've really appreciated the teamwork and honestly, quick turnaround vs. other vendors and projects."