Best Open Source Authorization & Permissions Tools using OpenAPI in 2026

Authentik

Take control of your identity with a secure, flexible solution

Stars
21,297
Forks
1,577
Last commit
9 hours ago

authentik is an open-source identity provider that offers self-hosted authentication, authorization, and user management for businesses of all sizes.

Open Source Alternative to:

Clerk

Ory

A certified and battle-tested identity solution

Stars
13,613
Forks
1,130
Last commit
3 days ago

Ory is a certified and battle-tested identity solution backed by a large open source community and trusted by Fortune 500 companies.

Open Source Alternative to:

Clerk

Stack Auth

Open-source authentication and user management platform

Stars
6,775
Forks
512
Last commit
2 days ago

Stack Auth provides secure authentication, authorization, and user management for developers in just 5 minutes.

Open Source Alternative to:

Clerk

Permify

Build scalable authorization in minutes, not months

Stars
5,865
Forks
310
Last commit
3 days ago

Open-source authorization service for implementing fine-grained access controls. Centralized, scalable solution supporting RBAC, ABAC and ReBAC with Google Zanzibar-inspired architecture.

Open Source Alternative to:

Auth0

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Authentik

Take control of your identity with a secure, flexible solution

Stars
21,297
Forks
1,577
Last commit
9 hours ago

authentik is an open-source identity provider that offers self-hosted authentication, authorization, and user management for businesses of all sizes.

Open Source Alternative to:

Clerk

Ory

A certified and battle-tested identity solution

Stars
13,613
Forks
1,130
Last commit
3 days ago

Ory is a certified and battle-tested identity solution backed by a large open source community and trusted by Fortune 500 companies.

Open Source Alternative to:

Clerk

Stack Auth

Open-source authentication and user management platform

Stars
6,775
Forks
512
Last commit
2 days ago

Stack Auth provides secure authentication, authorization, and user management for developers in just 5 minutes.

Open Source Alternative to:

Clerk

Permify

Build scalable authorization in minutes, not months

Stars
5,865
Forks
310
Last commit
3 days ago

Open-source authorization service for implementing fine-grained access controls. Centralized, scalable solution supporting RBAC, ABAC and ReBAC with Google Zanzibar-inspired architecture.

Open Source Alternative to:

Auth0

Open Source Authorization & Permissions Tools using OpenAPI

A curated collection of the best open source systems for defining and enforcing access control policies. using OpenAPI.