Authelia: The Lightweight SSO and 2FA Gate for Your Entire Self-Hosted Stack
Authelia is a 28k-star, Apache-2.0 single-binary SSO and two-factor gateway that bolts login and 2FA onto any app behind a reverse proxy. A 5,000-word teardown of forward-auth architecture, identity backends, TOTP/WebAuthn/Duo, access-control policies, the OpenID Connect certification it earned in 2026, the hard scope limits (no SAML, no federation, no multi-tenancy), and exactly where your credentials and sessions go.