Authentik

Authentik is an open-source identity provider that has rapidly gained popularity in the self-hosting community and is now being adopted by enterprises seeking alternatives to proprietary identity platforms like Okta and Auth0. Originally created as a personal project by Jens Langhammer in Hamburg, Germany, Authentik has matured into a feature-rich identity management platform that handles single sign-on, multi-factor authentication, user provisioning, and access control through a modern, visually appealing interface that sets it apart from older open-source identity tools.

What makes Authentik distinctive in the crowded identity management space is its approach to flexibility. Rather than imposing rigid authentication workflows, Authentik uses a flow-based architecture that allows administrators to design custom authentication, authorization, enrollment, and recovery processes through a visual flow editor. This means you can build login experiences as simple as username/password or as complex as multi-step verification with conditional logic, risk-based authentication, and custom prompts -- all without writing code.

Architecture and Deployment

Authentik is written in Python (Django) with a Go-based outpost system for protocol-level proxying. It deploys via Docker or Kubernetes, with official Helm charts available for production clusters. The architecture consists of a core server that handles the identity logic, a PostgreSQL database for persistent storage, and optional outpost containers that serve as protocol bridges (LDAP, RADIUS, or reverse proxy). Since the 2025.10 release, Redis is no longer required -- caching and WebSocket connections have been migrated to PostgreSQL, simplifying the deployment stack significantly.

For small deployments, a single Docker Compose setup with two containers (server + worker) plus PostgreSQL is sufficient. For production environments, the Kubernetes deployment supports horizontal scaling of the core server and outpost components. The entire system can run on modest hardware, making it practical for homelab users and small businesses as well as enterprise environments processing thousands of authentication requests per minute.

Protocol Support

Authentik supports all major authentication and federation protocols: OAuth2/OpenID Connect (OIDC), SAML 2.0, LDAP, RADIUS, and forward auth/reverse proxy patterns. This comprehensive protocol coverage means Authentik can serve as the identity backbone for virtually any application stack. Legacy applications that only support LDAP can authenticate through Authentik's LDAP outpost, while modern web applications use OIDC. Enterprise software requiring SAML federation works through Authentik's SAML provider.

The 2025.10 release introduced Single Logout (SLO) support for both SAML (back-channel and front-channel) and OIDC (front-channel). This is a significant enterprise feature that allows a user logging out of one application to be simultaneously logged out of all connected applications, addressing a common security requirement in regulated environments. Prior to this update, SLO was a notable gap compared to Keycloak and commercial identity providers.

Flow-Based Authentication Engine

Authentik's flow system is its most powerful and differentiating feature. Authentication, enrollment, password recovery, and user profile management are all defined as flows -- sequences of stages that can be connected with conditional logic. Stages include identification (username/email), password verification, MFA challenges (TOTP, WebAuthn/FIDO2, SMS, push notification), email verification, captcha, consent prompts, and custom form fields.

The flow editor provides a visual interface for designing these workflows, and policies can be attached to control stage visibility and branching. For example, you can create a flow that requires MFA only for users accessing sensitive applications, or one that prompts for additional verification when a login originates from an unfamiliar IP address. This level of customization is typically only available in expensive enterprise identity platforms -- having it in an open-source tool is remarkable.

Application Proxy and Zero Trust

Authentik includes a built-in application proxy that can protect web applications without modifying them. The proxy outpost sits in front of upstream applications and handles authentication, injecting identity headers (like X-authentik-username) that backend services can read. This is particularly valuable for self-hosted applications that lack built-in authentication -- rather than relying on each application's own user management, you centralize identity in Authentik and protect everything through the proxy.

The proxy supports both forward auth mode (working with existing reverse proxies like Traefik, nginx, or Caddy) and standalone mode. Combined with policies that can enforce conditions based on user attributes, group membership, IP address, time of day, and custom expressions, this creates a zero-trust access layer for your entire application stack.

User Management and Self-Service

The Authentik admin interface provides comprehensive user management with group-based access control, custom user attributes, and automated provisioning through SCIM. Users get a self-service portal where they can manage their profile, enroll MFA devices, view active sessions, and reset passwords without administrator intervention. The self-service capabilities reduce help desk load and improve user experience, which matters as deployments scale.

Authentik also supports social login (sign in with Google, GitHub, Apple, Microsoft, and other OAuth/OIDC providers) and can federate with external identity sources. SCIM provisioning allows Authentik to push and pull user data to and from connected applications, automating the lifecycle of user accounts across your organization's software stack.

Open Source and Enterprise Licensing

Authentik's core is open source and freely available on GitHub. The community edition includes all the identity management features most organizations need: SSO, MFA, LDAP, SAML, OIDC, flows, application proxy, and user management. The enterprise edition adds features aimed at larger organizations: remote access (RAC), AI-based risk detection, enterprise support SLAs, and advanced audit logging. The enterprise licensing model is per-user, making costs predictable and proportional to organization size.

The open-source foundation means organizations can audit the code, contribute fixes, and avoid vendor lock-in. If Authentik Security (the company) were to change direction, the community could fork and maintain the project. This is a fundamentally different risk profile than proprietary identity platforms like Okta, where customers are entirely dependent on the vendor's decisions about pricing, features, and data handling.

Comparison with Keycloak

Keycloak, backed by Red Hat, is the most established open-source identity provider and Authentik's primary competitor in the open-source space. Keycloak is more mature, has broader enterprise adoption, and offers features like fine-grained authorization services that Authentik does not yet match. However, Authentik is widely considered to have a significantly better user interface, simpler deployment model (Docker vs. Keycloak's Java-based stack), and a more intuitive configuration experience through its flow editor. For organizations without dedicated identity management teams, Authentik's lower operational complexity is a major advantage.

Who Should Choose Authentik

Authentik is an excellent choice for self-hosters who want centralized identity management for their application stack, small to mid-sized businesses seeking an open-source alternative to Okta or Auth0, and enterprises that need customizable authentication workflows with GDPR-compliant, self-hosted infrastructure. Its German origin, open-source transparency, and self-hosted deployment model make it one of the strongest options for organizations that want full control over their identity infrastructure while benefiting from European data governance principles.