Self-Host Authentik: Identity Provider and SSO 2026

TL;DR

Authentik (MIT, ~14K GitHub stars, Python/Django) is a comprehensive self-hosted identity provider. It provides SSO for all your self-hosted apps via OAuth2/OIDC, SAML 2.0, and a proxy authentication mode that protects apps that don't natively support authentication. Okta charges $2/user/month; Auth0 charges $23/month for 1,000 users. Authentik self-hosted is free for unlimited users and supports every major authentication protocol.

Key Takeaways

• Authentik: MIT, ~14K stars, Python — IdP with OAuth2, OIDC, SAML 2.0, LDAP, and proxy auth
• Proxy provider: Protect any app (even those without auth) behind Authentik's login
• Flows: Visual policy engine — customize login, enrollment, recovery, and MFA flows
• Outposts: Lightweight proxy components deployed next to apps for proxy authentication
• LDAP provider: Expose users as LDAP directory for legacy apps
• MFA: TOTP, WebAuthn (hardware keys), FIDO2 — all built in

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Authentik vs Authelia vs Keycloak

Feature	Authentik	Authelia	Keycloak
Admin UI	Excellent	Basic	Excellent
Proxy auth	Yes (Outposts)	Yes (built-in)	No
OAuth2/OIDC Provider	Yes	No	Yes
SAML Provider	Yes	No	Yes
LDAP Provider	Yes	No	Yes
Flow customization	Visual editor	Config file	Limited UI
RAM usage	~500MB	~50MB	~512MB+
Setup complexity	Medium	Simple	Complex
User management	Full UI	Config file	Full UI

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Part 1: Docker Setup

# docker-compose.yml
services:
  postgresql:
    image: docker.io/library/postgres:16-alpine
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -d $${POSTGRES_DB} -U $${POSTGRES_USER}"]
      interval: 5s
      start_period: 20s
    volumes:
      - authentik_db:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: "${PG_PASS}"
      POSTGRES_USER: authentik
      POSTGRES_DB: authentik

  redis:
    image: docker.io/library/redis:alpine
    command: --save 60 1 --loglevel warning
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "redis-cli ping | grep PONG"]
      interval: 5s
    volumes:
      - authentik_redis:/data

  server:
    image: ghcr.io/goauthentik/server:latest
    restart: unless-stopped
    command: server
    environment: &env
      AUTHENTIK_REDIS__HOST: redis
      AUTHENTIK_POSTGRESQL__HOST: postgresql
      AUTHENTIK_POSTGRESQL__USER: authentik
      AUTHENTIK_POSTGRESQL__NAME: authentik
      AUTHENTIK_POSTGRESQL__PASSWORD: "${PG_PASS}"
      AUTHENTIK_SECRET_KEY: "${AUTHENTIK_SECRET_KEY}"
      AUTHENTIK_EMAIL__HOST: mail.yourdomain.com
      AUTHENTIK_EMAIL__PORT: 587
      AUTHENTIK_EMAIL__USERNAME: authentik@yourdomain.com
      AUTHENTIK_EMAIL__PASSWORD: "${MAIL_PASSWORD}"
      AUTHENTIK_EMAIL__USE_TLS: "true"
      AUTHENTIK_EMAIL__FROM: authentik@yourdomain.com
    volumes:
      - authentik_media:/media
      - authentik_templates:/templates
    ports:
      - "9000:9000"
      - "9443:9443"
    depends_on:
      - postgresql
      - redis

  worker:
    image: ghcr.io/goauthentik/server:latest
    restart: unless-stopped
    command: worker
    environment: *env
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - authentik_media:/media
      - authentik_certs:/certs
      - authentik_templates:/templates
    depends_on:
      - postgresql
      - redis

volumes:
  authentik_db:
  authentik_redis:
  authentik_media:
  authentik_certs:
  authentik_templates:

# Generate secrets:
echo "PG_PASS=$(openssl rand -base64 36)" >> .env
echo "AUTHENTIK_SECRET_KEY=$(openssl rand -base64 60)" >> .env

docker compose up -d

# Get initial admin password from logs (first run):
docker compose logs server | grep "Initial admin credentials"

---

Part 2: HTTPS with Caddy

auth.yourdomain.com {
    reverse_proxy localhost:9000
}

Visit https://auth.yourdomain.com/if/flow/initial-setup/ → set admin password.

---

Part 3: OAuth2/OIDC Provider (Protect an App)

Protect an app that supports OAuth2/OIDC natively (Gitea, Nextcloud, Grafana, etc.):

Create an OAuth2 Provider

1. Applications → Providers → Create → OAuth2/OpenID Provider
2. Name: Gitea
3. Authorization flow: default-provider-authorization-explicit-consent
4. Client type: Confidential
5. Copy: Client ID and Client Secret
6. Redirect URIs: https://gitea.yourdomain.com/user/oauth2/authentik/callback
7. Scopes: openid, email, profile

Create an Application

1. Applications → Applications → Create
2. Name: Gitea
3. Provider: select Gitea (the provider you just created)
4. Launch URL: https://gitea.yourdomain.com

Configure Gitea

# app.ini
[oauth2]
ENABLED = true

# Add via Gitea admin UI → Site Administration → Authentication Sources → Add
# Provider: OpenID Connect
# Client ID: from Authentik
# Client Secret: from Authentik
# Auto Discovery URL: https://auth.yourdomain.com/application/o/gitea/.well-known/openid-configuration

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Part 4: Proxy Provider (Protect Any App)

The proxy provider protects apps that have no built-in authentication:

How it works

Browser → Caddy → Authentik Outpost (proxy) → Your App
                  ↑ checks session with Authentik server

Create a Proxy Provider

1. Applications → Providers → Create → Proxy Provider
2. Name: Portainer
3. Mode: Forward auth (single application)
4. External host: https://portainer.yourdomain.com
5. Internal host: http://portainer:9000
6. Skip path regex (optional): /api/webhooks/.*

Create an Outpost

1. Applications → Outposts → Create
2. Name: proxy-outpost
3. Type: Proxy
4. Integration: Docker (uses the Docker socket)
5. Applications: select all apps using proxy providers

Authentik automatically deploys the outpost container.

Configure Caddy for forward auth

portainer.yourdomain.com {
    forward_auth localhost:9000 {
        uri /outpost.goauthentik.io/auth/caddy
        copy_headers X-Authentik-Username X-Authentik-Groups X-Authentik-Email
        trusted_proxies private_ranges
    }
    reverse_proxy localhost:9000
}

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Part 5: MFA Configuration

Enable TOTP (Authenticator apps)

1. Flows & Stages → Stages → Create → Authenticator TOTP Stage
2. Name: totp-setup
3. Flows → default-authentication-flow → Edit
4. Add stage binding: totp-setup after password stage

Enable WebAuthn (Hardware keys / biometrics)

1. Flows & Stages → Stages → Create → Authenticator WebAuthn Stage
2. Name: webauthn-setup
3. Add to authentication flow

Require MFA for specific groups

# In your authentication flow, add a Policy Binding:
# - Expression policy that checks group membership:
return request.user.ak_groups.filter(name="Admins").exists()

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Part 6: LDAP Provider

Expose Authentik users as an LDAP directory for legacy apps (Synology, older software):

1. Applications → Providers → Create → LDAP Provider
2. Name: ldap
3. Bind DN: cn=admin,dc=yourdomain,dc=com
4. Certificate: select your TLS cert

Create LDAP Outpost

1. Applications → Outposts → Create
2. Type: LDAP
3. Port mapping: 389:3389 (LDAP), 636:6636 (LDAPS)

Test LDAP connection

ldapsearch -H ldap://localhost:389 \
  -D "cn=admin,dc=yourdomain,dc=com" \
  -w "admin-password" \
  -b "dc=yourdomain,dc=com" \
  "(objectClass=person)"

---

Part 7: User Enrollment and Invitation

Self-registration flow

1. Flows & Stages → Flows → Create
2. Designation: Enrollment
3. Stages: Email verification → User write → Username field → Password field
4. Assign as: default-user-settings-flow

Invitation links

Create single-use or multi-use invitation links:

1. Directory → Invitations → Create
2. Expires: optional date
3. Copy invitation link → send to new user

Disable public registration

# In Authentik admin:
# Flows → default-user-settings-flow → Edit
# Remove "Public" from Flow permissions
# Or: Policies → Expression Policy → "return False" → bind to enrollment flow

---

Part 8: Backup and Restore

# Backup database:
docker exec authentik-postgresql-1 pg_dump -U authentik authentik \
  | gzip > authentik-db-$(date +%Y%m%d).sql.gz

# Backup media (custom logos, etc.):
tar -czf authentik-media-$(date +%Y%m%d).tar.gz \
  $(docker volume inspect authentik_authentik_media --format '{{.Mountpoint}}')

# Export configuration as YAML blueprint:
docker exec authentik-server-1 ak export_blueprint > authentik-blueprint-$(date +%Y%m%d).yaml

# Restore database:
gunzip < authentik-db-YYYYMMDD.sql.gz | \
  docker exec -i authentik-postgresql-1 psql -U authentik authentik

# Logs:
docker compose logs -f server worker

Why Self-Host Authentik?

The case for self-hosting Authentik comes down to three practical factors: data ownership, cost at scale, and operational control.

Data ownership is the fundamental argument. When you use a SaaS version of any tool, your data lives on someone else's infrastructure subject to their terms of service, their security practices, and their business continuity. If the vendor raises prices, gets acquired, changes API limits, or shuts down, you're left scrambling. Self-hosting Authentik means your data and configuration stay on infrastructure you control — whether that's a VPS, a bare metal server, or a home lab.

Cost at scale matters once you move beyond individual use. Most SaaS equivalents charge per user or per data volume. A self-hosted instance on a $10-20/month VPS typically costs less than per-user SaaS pricing for teams of five or more — and the cost doesn't scale linearly with usage. One well-configured server handles dozens of users for a flat monthly fee.

Operational control is the third factor. The Docker Compose configuration above exposes every setting that commercial equivalents often hide behind enterprise plans: custom networking, environment variables, storage backends, and authentication integrations. You decide when to update, how to configure backups, and what access controls to apply.

The honest tradeoff: you're responsible for updates, backups, and availability. For teams running any production workloads, this is familiar territory. For individuals, the learning curve is real but the tooling (Docker, Caddy, automated backups) is well-documented and widely supported.

Server Requirements and Sizing

Before deploying Authentik, assess your server capacity against expected workload.

Minimum viable setup: A 1 vCPU, 1GB RAM VPS with 20GB SSD is sufficient for personal use or small teams. Most consumer VPS providers — Hetzner, DigitalOcean, Linode, Vultr — offer machines in this range for $5-10/month. Hetzner offers excellent price-to-performance for European and US regions.

Recommended production setup: 2 vCPUs with 4GB RAM and 40GB SSD handles most medium deployments without resource contention. This gives Authentik headroom for background tasks, caching, and concurrent users while leaving capacity for other services on the same host.

Storage planning: The Docker volumes in this docker-compose.yml store all persistent Authentik data. Estimate your storage growth rate early — for data-intensive tools, budget for 3-5x your initial estimate. Hetzner Cloud and Vultr both support online volume resizing without stopping your instance.

Operating system: Any modern 64-bit Linux distribution works. Ubuntu 22.04 LTS and Debian 12 are the most commonly tested configurations. Ensure Docker Engine 24.0+ and Docker Compose v2 are installed — verify with docker --version and docker compose version. Avoid Docker Desktop on production Linux servers; it adds virtualization overhead and behaves differently from Docker Engine in ways that cause subtle networking issues.

Network: Only ports 80 and 443 need to be publicly accessible when running behind a reverse proxy. Internal service ports should be bound to localhost only. A minimal UFW firewall that blocks all inbound traffic except SSH, HTTP, and HTTPS is the single most effective security measure for a self-hosted server.

Backup and Disaster Recovery

Running Authentik without a tested backup strategy is an unacceptable availability risk. Docker volumes are not automatically backed up — if you delete a volume or the host fails, data is gone with no recovery path.

What to back up: The named Docker volumes containing Authentik's data (database files, user uploads, application state), your docker-compose.yml and any customized configuration files, and .env files containing secrets.

Backup approach: For simple setups, stop the container, archive the volume contents, then restart. For production environments where stopping causes disruption, use filesystem snapshots or database dump commands (PostgreSQL pg_dump, SQLite .backup, MySQL mysqldump) that produce consistent backups without downtime.

For a complete automated backup workflow that ships snapshots to S3-compatible object storage, see the Restic + Rclone backup guide. Restic handles deduplication and encryption; Rclone handles multi-destination uploads. The same setup works for any Docker volume.

Backup cadence: Daily backups to remote storage are a reasonable baseline for actively used tools. Use a 30-day retention window minimum — long enough to recover from mistakes discovered weeks later. For critical data, extend to 90 days and use a secondary destination.

Restore testing: A backup that has never been restored is a backup you cannot trust. Once a month, restore your Authentik backup to a separate Docker Compose stack on different ports and verify the data is intact. This catches silent backup failures, script errors, and volume permission issues before they matter in a real recovery.

Security Hardening

Self-hosting means you are responsible for Authentik's security posture. The Docker Compose setup provides a functional base; production deployments need additional hardening.

Always use a reverse proxy: Never expose Authentik's internal port directly to the internet. The docker-compose.yml binds to localhost; Caddy or Nginx provides HTTPS termination. Direct HTTP access transmits credentials in plaintext. A reverse proxy also centralizes TLS management, rate limiting, and access logging.

Strong credentials: Change default passwords immediately after first login. For secrets in docker-compose environment variables, generate random values with openssl rand -base64 32 rather than reusing existing passwords.

Firewall configuration:

ufw default deny incoming
ufw allow 22/tcp
ufw allow 80/tcp
ufw allow 443/tcp
ufw enable

Internal service ports (databases, admin panels, internal APIs) should only be reachable from localhost or the Docker network, never directly from the internet.

Network isolation: Docker Compose named networks keep Authentik's services isolated from other containers on the same host. Database containers should not share networks with containers that don't need direct database access.

VPN access for sensitive services: For internal-only tools, restricting access to a VPN adds a strong second layer. Headscale is an open source Tailscale control server that puts your self-hosted stack behind a WireGuard mesh, eliminating public internet exposure for internal tools.

Update discipline: Subscribe to Authentik's GitHub releases page to receive security advisory notifications. Schedule a monthly maintenance window to pull updated images. Running outdated container images is the most common cause of self-hosted service compromises.

Troubleshooting Common Issues

Container exits immediately or won't start

Check logs first — they almost always explain the failure:

docker compose logs -f authentik

Common causes: a missing required environment variable, a port already in use, or a volume permission error. Port conflicts appear as bind: address already in use. Find the conflicting process with ss -tlpn | grep PORT and either stop it or change Authentik's port mapping in docker-compose.yml.

Cannot reach the web interface

Work through this checklist:

1. Confirm the container is running: docker compose ps
2. Test locally on the server: curl -I http://localhost:PORT
3. If local access works but external doesn't, check your firewall: ufw status
4. If using a reverse proxy, verify it's running and the config is valid: caddy validate --config /etc/caddy/Caddyfile

Permission errors on volume mounts

Some containers run as a non-root user. If the Docker volume is owned by root, the container process cannot write to it. Find the volume's host path with docker volume inspect VOLUME_NAME, check the tool's documentation for its expected UID, and apply correct ownership:

chown -R 1000:1000 /var/lib/docker/volumes/your_volume/_data

High resource usage over time

Memory or CPU growing continuously usually indicates unconfigured log rotation, an unbound cache, or accumulated data needing pruning. Check current usage with docker stats authentik. Add resource limits in docker-compose.yml to prevent one container from starving others. For ongoing visibility into resource trends, deploy Prometheus + Grafana or Netdata.

Data disappears after container restart

Data stored in the container's writable layer — rather than a named volume — is lost when the container is removed or recreated. This happens when the volume mount path in docker-compose.yml doesn't match where the application writes data. Verify mount paths against the tool's documentation and correct the mapping. Named volumes persist across container removal; only docker compose down -v deletes them.

Keeping Authentik Updated

Authentik follows a regular release cadence. Staying current matters for security patches and compatibility. The update process with Docker Compose is straightforward:

docker compose pull          # Download updated images
docker compose up -d         # Restart with new images
docker image prune -f        # Remove old image layers (optional)

Read the changelog before major version updates. Some releases include database migrations or breaking configuration changes. For major version bumps, test in a staging environment first — run a copy of the service on different ports with the same volume data to validate the migration before touching production.

Version pinning: For stability, pin to a specific image tag in docker-compose.yml instead of latest. Update deliberately after reviewing the changelog. This trades automatic patch delivery for predictable behavior — the right call for business-critical services.

Post-update verification: After updating, confirm Authentik is functioning correctly. Most services expose a /health endpoint that returns HTTP 200 — curl it from the server or monitor it with your uptime tool.

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See also: Authelia — simpler authentication middleware with lower resource requirements

See all open source security tools at OSSAlt.com/categories/security.

See open source alternatives to Authentik on OSSAlt.