WHAT IS IT?
Zitadel is an open-source identity and access management (IAM) platform written in Go. It provides everything you need to handle authentication and authorization for your users: SSO, MFA, Passkeys, OIDC, SAML 2.0, SCIM 2.0 and a battle-tested multi-tenancy model. The approach is API-first with gRPC, connectRPC and REST support.
WHY IS IT INTERESTING?
- Native multi-tenancy: The architecture is designed from the ground up to manage multiple organizations with strict hierarchy and infrastructure-level data isolation. No hacks needed - it's baked into the project's DNA.
- Full standards support: OpenID Connect certified, SAML 2.0, SCIM 2.0, FIDO2/WebAuthn. Covers B2C, B2B and internal use cases without juggling multiple tools.
- Event-driven audit trail: Every action is tracked through an event-driven system accessible via API. Perfect for compliance (SOC2, GDPR, ISO 27001) without extra development work.
- Passkeys and passwordless: Native FIDO2/WebAuthn support for passwordless authentication. MFA, social login, identity brokering - all built in.
- API-first and scalable: gRPC and REST, zero-downtime updates, horizontal scalability. Integration into an existing stack is done cleanly through APIs, not a monolithic SDK.
- Self-hosted or cloud: Deploy on your own infrastructure or use the managed SaaS offering. You stay in control of your identity data.
USE CASES
- Replace Auth0 or Keycloak with an open-source solution featuring native multi-tenancy
- Set up SSO and identity brokering for a B2B SaaS platform
- Manage authentication for multiple organizations from a single instance
- Implement passwordless auth (Passkeys/WebAuthn) without building all the plumbing
- Centralize identity audit trails to meet compliance requirements