Assembly Line

Keto

The most scalable and customizable permission server on the market. Fix your slow or broken permission system with Google's proven "Zanzibar" approach. Supports ACL, RBAC, and more. Written in Go, cloud native, headless, API-first. Available as a service on Ory Network and for self-hosters.

Keto is an open-source authorization engine project on GitHub under the Apache-2.0 license (permissive), with 5.4k stars. It is built with Go, Postgres and Mongo. Its last push was 2 months ago.

Stars
5.4k
License
Apache-2.0
Activity
Active
Latest release
v26.2.0

Code on GitHub Website

Judgement

What it is
Building block
What it does
Ory's Zanzibar-style permission server for relationship-based access checks over REST and gRPC.
Adopt it when
You already use Ory Kratos or Hydra and want permissions from the same stack.
Watch out
Its permission language is less mature than SpiceDB's, and Ory steers users towards its paid network.
Ready for
Usable
Runs as
Self-hosted server and cloud service
Built with
Go and PostgreSQL
How established
Established: started 8 years ago, latest release v26.2.0.
What the license allows
You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-03 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

GoPostgresMongo

Follow it down: Keto → Go → runs on a microchip

How compilers were built, back to punched paper tape

Open-source alternatives to Keto

  1. 1
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  4. 4
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Commercial authorization and permission engines

  1. 1
    Oso Cloud Oso Security

    Oso helps companies run agents in production with confidence using monitoring, access controls, and automated least privilege.

    Building block Usable Your app has outgrown hand-coded role checks and needs relationship- or attribute-based permissions.

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  2. 2
    AuthZed Cloud AuthZed

    Remove authorization bottlenecks, empower your team to innovate and expand with best-in-class performance at any scale.

    Building block Production-ready A product needs Google Docs-style sharing permissions at scale and the team is ready to adopt a relationship model.

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  3. 3
    Styra DAS Styra

    Complete system Usable A platform team runs OPA in many places and wants central policy management and impact analysis.

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Stars, license and activity come from GitHub and refresh on a rolling hourly schedule. The project's own description is quoted as written.