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Cybersecurity · head to head

authentik vs Seldon

authentik logo

authentik

Cybersecurity

Open-source identity provider with flexible authentication flows

From
Free
Rated
-
Full reviewWebsite
Seldon logo

Seldon

Machine Learning

Kubernetes model serving whose current version is licensed under the Business Source Licence

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: authentik smaller project than Keycloak, with a correspondingly smaller community and fewer integration guides; Seldon seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • They diverge on capability: authentik covers Configurable flows, Seldon covers Kubernetes custom resources.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which authentik and Seldon actually diverge.

Attributes where authentik and Seldon differ
AttributeauthentikSeldon
Pricing modelOpen-source core with a paid enterprise tierfreemium
PlatformsDocker, Kubernetes, Linux, Self-hostedLinux
CategoryCybersecurityMachine Learning
FoundedUnknown2014

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in authentik

  • Configurable flows
  • Protocol support
  • Application proxy
  • Modern admin interface

Only in Seldon

  • Kubernetes custom resources
  • Inference graphs
  • Traffic strategies
  • Open Inference Protocol
  • Alibi Explain
  • Alibi Detect
  • Kafka-backed pipelines in v2
  • Commercial control plane

What people use each for

The jobs each tool is most often brought in to do.

authentik

  • Self-hosted SSO across internal services without commercial identity pricingnot Seldon
  • Putting authentication in front of applications that have none, via the proxynot Seldon
  • Teams who tried Keycloak and wanted something less heavynot Seldon

Seldon

  • Serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate servicesnot authentik
  • Running genuine production experiments where a share of live traffic goes to a candidate model and the results are comparednot authentik
  • Regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on laternot authentik
  • Organisations with an established Kubernetes platform team who want serving expressed as manifests under existing deployment controlsnot authentik

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

authentik

  • Smaller project than Keycloak, with a correspondingly smaller community and fewer integration guides
  • The flow model is flexible but conceptually unfamiliar, and simple setups can feel over-abstracted
  • Enterprise support and some governance features sit behind the paid tier
  • Self-hosted identity is still yours to secure, patch and keep available

Seldon

  • Seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • Core v1 remains Apache 2.0 but is in maintenance, so taking the free route means running software that receives no new development while the architecture it belongs to moves on without it.
  • Version 2 is a different system rather than a newer release, with different custom resources, a scheduler component and a Kafka-based pipeline model, so migrating from v1 is a re-implementation of every deployment manifest rather than an upgrade.
  • Kafka is a dependency for v2 pipelines, so an organisation that does not already operate it takes on a distributed log with its own storage, retention, rebalancing and failure modes purely in order to serve models.
  • Everything assumes Kubernetes fluency and the failure modes are Kubernetes failure modes, custom resource version mismatches, an operator that will not reconcile, admission webhooks and resource limits terminating an inference pod mid-request, so it needs a platform engineer rather than a data scientist.

Pricing, plan by plan

authentik

Free
  • Open sourceFree
    • Full identity provider
    • All protocols
    • Community support

Seldon

Free
  • Seldon CoreFree
    • Open source
    • Kubernetes deployment
    • Model serving
  • Seldon DeployFree
    • Enterprise features
    • GUI
    • Monitoring

Which should you pick?

Choose authentik if

  • You need configurable flows.
  • You want to start without paying.
  • You work on Docker, Kubernetes, Linux, Self-hosted.
  • You also want protocol support.
authentik review

Choose Seldon if

  • You need kubernetes custom resources.
  • You want to start without paying.
  • You work on Linux.
  • You also want inference graphs.
Seldon review

Questions people ask

Is authentik or Seldon better?
Neither clearly leads. authentik starts at Free and Seldon at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, authentik or Seldon?
authentik starts at Free and Seldon at Free.
Does authentik or Seldon run on more platforms?
authentik runs on Docker, Kubernetes, Linux, Self-hosted. Seldon runs on Linux.
Can I use authentik for free?
Both have a free tier, so you can try either at no cost before committing.
What is authentik best used for?
authentik is most often used for self-hosted sso across internal services without commercial identity pricing, putting authentication in front of applications that have none, via the proxy, teams who tried keycloak and wanted something less heavy. Of those, self-hosted sso across internal services without commercial identity pricing and putting authentication in front of applications that have none, via the proxy are not what Seldon is typically brought in for.
What can authentik do that Seldon cannot?
authentik covers Configurable flows, Protocol support, Application proxy, Modern admin interface. Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol.

Answered from the vendors’ own pages

authentik: Is authentik free?

The open-source edition is free and complete for most use. An enterprise tier adds support and additional features.

Seldon: Is Seldon open source?

Partly, and this is the thing to check before you build on it. Core v1 is Apache 2.0 but in maintenance. Core v2 was moved to the Business Source Licence in 2024, which allows evaluation but not unlicensed production use. Verify the current licence of each component you intend to run, including MLServer and the Alibi libraries.

authentik: authentik or Keycloak?

authentik is generally reported as easier to run and administer; Keycloak is more established with a larger community and Red Hat behind it.

Seldon: What is the difference between v1 and v2?

Architecture, not just version number. v2 introduces a scheduler, a different set of custom resources and Kafka-backed pipelines. Manifests, mental model and operations all change, so treat a move as a project.

authentik: Can authentik protect apps with no login of their own?

Yes. Its application proxy places authentication in front of services that have no built-in authentication.

Seldon: Do I need Kubernetes?

Yes. It is a Kubernetes-native system and there is no meaningful deployment without a cluster and someone competent to run it.

Seldon: What is MLServer?

Seldon's Python inference server implementing the Open Inference Protocol, usable inside Seldon deployments or on its own. Check its current licence alongside Core's, since the company has moved projects onto the Business Source Licence.

Seldon: Do I have to run Kafka?

For v2 pipelines, yes. If you only need single models served, that dependency is a large amount of infrastructure for the benefit, and a simpler serving layer may be the better answer.

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