What is Authentik? Learn how this open-source identity provider works, its flow-based authentication engine, and how it compares to Keycloak.

If Keycloak’s admin console felt more complex than your project actually needed, or you’ve been searching for a self-hosted identity provider that feels more like a modern product than enterprise Java infrastructure, Authentik is probably the name you’ve kept running into. So what is Authentik, and how does it actually work? This guide covers the core concepts, its distinctive flow-based architecture, and how it stacks up against the more established alternatives.

What is Authentik?

Authentik is an open-source identity provider (IdP) that handles authentication and authorization for applications, supporting the same core industry-standard protocols as other IAM platforms, OAuth 2.0, OpenID Connect, SAML, and LDAP, while taking a notably different architectural approach to how authentication logic is actually configured. Rather than exposing authentication settings as a fixed set of toggles and dropdowns, Authentik models the entire login experience as a configurable, visual flow, a sequence of stages a user moves through, which can be customized, reordered, and extended with custom logic far more directly than most alternatives allow.

Authentik is developed by a company of the same name (goauthentik) and has built a strong following particularly within the self-hosted and homelab community, alongside genuine adoption in production environments at small and mid-sized organizations. It’s built on Python and Django, with a modern web UI, and has positioned itself as a more approachable, developer-friendly alternative to older, more enterprise-oriented identity platforms.

The Problem Authentik Solves

The underlying problem, centralizing authentication instead of building it into every application separately, is the same one every identity provider addresses. What differentiates Authentik is who it’s built for and how approachable it aims to be.

Established enterprise IAM tools often carry real complexity, sensible for large organizations with dedicated identity teams, but genuinely heavy for a small team or an individual self-hosting a handful of internal tools who just wants working single sign-on without becoming an expert in enterprise Java configuration first. Authentik’s design goal is to make self-hosted identity management accessible without giving up the flexibility power users and growing organizations actually need.

The other problem Authentik addresses more directly than most alternatives is authentication flow customization. Many identity providers assume a fairly standard login sequence: enter a username, enter a password, maybe a second factor. Real-world requirements are often messier, conditional multi-factor authentication based on the application being accessed, custom branding per application, integrating a legacy application that doesn’t natively support any modern protocol at all. Authentik’s flow-based architecture is built specifically to make these kinds of customizations configurable rather than requiring custom code or workarounds.

How Authentik Works: Core Architecture

Authentik’s architecture centers on a few distinctive concepts, and understanding them is the clearest way to understand what sets it apart.

Flows and Stages

A flow is a defined sequence of steps a user moves through, for login, for enrollment (self-registration), for password recovery, or for any other multi-step authentication process. Each individual step within a flow is a stage, a discrete unit like “prompt for username and password,” “verify a one-time password,” “show a custom consent screen,” or “enroll a new user’s profile information.”

This is genuinely different from how most identity providers work. Rather than a fixed login form with a small number of configurable options, Authentik lets you construct the entire authentication sequence yourself: reordering stages, adding conditional logic to skip a stage under certain conditions, or inserting custom stages entirely. A login flow requiring multi-factor authentication only for administrative users, or only when accessing a specific sensitive application, is a native configuration in Authentik’s flow model, rather than a workaround bolted onto a more rigid system.

Providers

A provider in Authentik represents the protocol-specific configuration connecting Authentik to a particular application, an OAuth2/OIDC provider, a SAML provider, an LDAP provider, or a Proxy provider (covered below). Providers define how Authentik communicates with a given application using that application’s expected protocol.

Applications

Applications are the user-facing representation of something a user can access, each application is linked to a provider that handles the actual protocol mechanics. This separation, providers handling protocol details, applications representing what a user actually sees and clicks on, keeps the configuration model clean as you add more integrated applications over time.

Outposts and the Proxy Provider

This is one of Authentik’s most practically useful features for real-world deployments. Many internal tools and legacy applications don’t natively support OAuth2, OIDC, or SAML at all, they might only have basic HTTP authentication, or no authentication mechanism worth relying on. Authentik’s Proxy Provider, deployed through a component called an Outpost, sits in front of such an application as a reverse proxy, handling authentication itself and only forwarding traffic through once a user has successfully authenticated with Authentik.

This means you can add single sign-on to an application that was never built with any modern identity protocol in mind, without modifying that application’s code at all, a genuinely valuable capability for organizations with a mix of modern and legacy internal tools.

Sources

Sources are Authentik’s mechanism for federating identity from external systems, connecting to an existing LDAP or Active Directory server, or brokering login through an external OAuth2/OIDC or SAML provider (Google, GitHub, or another organization’s identity provider), similar in concept to Keycloak’s identity federation, letting Authentik serve as a unifying layer on top of identity sources you already have.

Policies

Policies are conditions attached to stages, applications, or other parts of Authentik’s configuration, controlling whether a given step applies, or whether access is granted, based on expressions you define. Authentik supports expression-based policies written in Python, giving genuinely deep customization for conditional logic, requiring a specific stage only for users in a particular group, for instance, without needing an external system or workaround to achieve it.

Blueprints

Blueprints let you define Authentik’s configuration, flows, providers, applications, policies, as YAML files rather than exclusively through the admin UI, enabling configuration-as-code practices: version-controlling your identity configuration in Git, reviewing changes through pull requests, and deploying configuration consistently across environments, the same practices most teams already apply to their infrastructure and application code.

A Simple Example: Running Authentik Locally

The fastest way to try Authentik is through its official Docker Compose setup:

mkdir authentik-tutorial && cd authentik-tutorial
curl -O https://goauthentik.io/docker-compose.yml

Add a .env file with a couple of required values (Authentik’s documentation covers the current minimum required variables, typically a secret key and initial admin password), then start it:

docker compose up -d

Once running, the admin interface is available at http://localhost:9000/if/admin/, where you can log in with the initial admin credentials you configured. From there, creating a working integration for a test application generally follows this pattern: create a Provider (an OAuth2/OIDC provider, for a typical modern web application), create an Application linked to that provider, and Authentik automatically uses its default authentication flow unless you’ve configured a custom one. Your test application can then be configured to use Authentik’s OIDC endpoints for login, the same standard OIDC integration pattern that would work with any compliant identity provider.

Authentik vs Keycloak

Since these two are frequently compared directly, given how much they overlap in what they’re fundamentally trying to do, it’s worth a direct comparison.

Configuration philosophy. Keycloak’s configuration is comprehensive but follows a more traditional, form-and-dropdown administrative model. Authentik’s flow-based architecture gives a fundamentally more visual, composable way to build custom authentication sequences, arguably Authentik’s single clearest technical differentiator.

Legacy application support. Authentik’s Outpost/Proxy Provider model for adding SSO to applications with no native protocol support is more polished and commonly highlighted than Keycloak’s equivalent capabilities, which exist but are less central to Keycloak’s own design and documentation.

Maturity and enterprise track record. Keycloak has a considerably longer production history, is now a CNCF incubating project, and has been deployed at larger scale across a wider range of enterprise environments over a longer period of time. Authentik is younger, with a fast-growing but comparatively smaller track record specifically at very large enterprise scale.

User interface and approachability. Authentik is frequently described as feeling more modern and approachable, particularly for smaller teams or individuals without a background in enterprise identity management. Keycloak’s interface is functional but reflects its more enterprise-Java-oriented origins.

Community and ecosystem size. Keycloak’s community, plugin ecosystem, and volume of existing documentation and third-party integration guides are considerably larger, a natural consequence of its longer history and CNCF backing.

For a deeper look at Keycloak specifically, see our What is Keycloak guide, and our Keycloak vs Okta comparison for how Keycloak stacks up against a commercial managed alternative, a comparison that largely applies to Authentik vs Okta as well, given how similarly positioned the two open-source options are relative to a managed SaaS platform.

Common Use Cases for Authentik

Authentik shows up across a range of self-hosted and small-to-mid-sized organization identity needs:

• Homelab and self-hosted application authentication, adding SSO across a personally or small-team-managed collection of self-hosted tools and services
• Small to mid-sized business identity management, providing centralized authentication without the operational overhead some organizations feel Keycloak or a commercial platform would require
• Legacy application SSO, using the Proxy Provider and Outposts to add modern authentication to internal tools that were never built with OAuth2, OIDC, or SAML support
• Custom, conditional authentication flows, organizations with genuinely unusual login requirements (conditional MFA, custom enrollment steps, application-specific branding) that benefit directly from Authentik’s flow-based configuration model
• Configuration-as-code identity management, teams wanting to version-control and review identity configuration changes through Blueprints rather than relying solely on manual admin UI changes

Deployment Options

Authentik is self-hosted, similar to Keycloak, with a few common deployment paths.

Docker Compose, the most common starting point, suitable for small deployments and personal or small-team use, as shown in the quick start example above.

Kubernetes, via Authentik’s official Helm chart, for organizations wanting to run it as part of a broader cloud-native infrastructure setup, with the scaling and resilience benefits that come with Kubernetes-native deployment.

Both deployment methods require a backing PostgreSQL database and Redis instance, both included by default in Authentik’s standard Docker Compose setup, simplifying initial setup considerably compared to configuring these dependencies manually.

Benefits of Using Authentik

Pulling together what makes Authentik distinct:

A genuinely flexible authentication flow engine. The Flows and Stages model gives you configuration-level control over authentication sequences that most alternatives require custom code or workarounds to achieve.

Strong legacy application support. The Proxy Provider and Outpost model makes adding SSO to applications with no native protocol support a well-supported, first-class use case rather than an afterthought.

A modern, approachable interface. Authentik’s UI is frequently cited as more intuitive for teams without deep prior enterprise identity management experience.

Configuration-as-code support. Blueprints let identity configuration be version-controlled and reviewed like any other infrastructure code.

Active development and community. Authentik has seen rapid feature development and a growing, engaged community, particularly strong within the self-hosted and homelab space.

Challenges and Things to Consider

Authentik isn’t without real tradeoffs worth being upfront about.

It’s younger and has a smaller production track record at very large enterprise scale compared to Keycloak, which matters for organizations specifically prioritizing a long, extensively battle-tested history for security-critical infrastructure.

The ecosystem of existing documentation, third-party guides, and community-contributed troubleshooting resources, while growing quickly, is smaller than Keycloak’s considerably longer-established community.

As with any self-hosted identity provider, you’re responsible for the same operational burdens as with Keycloak, infrastructure, patching, high availability, and backup strategy, none of which are inherited automatically the way they would be with a managed service like Okta.

Authentik’s specific terminology, Flows, Stages, Outposts, does add a learning curve of its own, distinct from the more universally recognized concepts used by other identity providers, meaning some initial ramp-up time even for administrators already familiar with identity management concepts generally.

Frequently Asked Questions About Authentik

Is Authentik free to use? Yes, Authentik’s core platform is open source and free to self-host, with no per-user licensing cost. A commercial Enterprise tier exists offering additional features and support for organizations wanting that on top of the open-source core.

Is Authentik a good choice for a large enterprise? It can be, and is used in production at real scale by some organizations, but it has a shorter track record at very large enterprise scale compared to more established options like Keycloak or Okta. Organizations with extensive compliance and scale requirements should evaluate carefully against their specific needs.

How does the Proxy Provider actually work? An Outpost running the Proxy Provider sits as a reverse proxy in front of your target application. Incoming requests are intercepted, the user is required to authenticate with Authentik if they haven’t already, and only authenticated requests are forwarded through to the actual application, which doesn’t need any awareness of Authentik or any authentication protocol at all.

Can Authentik replace an existing LDAP or Active Directory setup? Not necessarily replace, Authentik commonly integrates with an existing LDAP or Active Directory server as a Source, similarly to how Keycloak handles identity federation, letting you keep your existing directory as the source of truth while adding modern protocol support on top of it.

Does Authentik support multi-factor authentication? Yes, including TOTP-based one-time passwords and other authentication methods, configurable as stages within your authentication flows, including conditional logic for when MFA should be required.

How does Authentik compare to Okta specifically? The comparison is largely the same shape as Keycloak vs Okta: Authentik is self-hosted and free with full control and customization, while Okta is a managed, commercial service with less operational burden but an ongoing subscription cost and less deep customization. See our Keycloak vs Okta comparison for the detailed version of that tradeoff, which applies similarly here.

Wrapping Up

So, what is Authentik, in a single sentence? It’s an open-source identity provider built around a flexible, visual, flow-based authentication engine, giving self-hosted teams a modern, approachable alternative to more established enterprise IAM platforms, with particularly strong support for bringing legacy applications into a unified single sign-on setup.

Whether Authentik or Keycloak is the better fit for your organization often comes down to how much you value Authentik’s more approachable interface and flexible flow configuration against Keycloak’s longer track record, larger ecosystem, and CNCF backing. Both are strong, genuinely free, self-hosted options, and the right choice depends more on your team’s specific priorities than any clear technical superiority of one over the other.

For deeper technical reference as you evaluate or start building, the official Authentik documentation covers flow configuration, provider setup, and deployment guides in far more depth than a single overview article can.