Zitadel Cloud

ZITADEL is an open-source identity and access management platform, providing authentication, authorization, and multi-tenancy capabilities for modern cloud applications. Developed by CAOS AG (a Swiss company) and with over 10,000 stars as of 2026, ZITADEL positions itself as a open-source alternative to Auth0, Okta, and Keycloak, with a strong focus on multi-tenancy and cloud-native architecture. Unlike Keycloak which requires significant infrastructure to operate, ZITADEL is designed as a turnkey solution that can be self-hosted or used as a managed cloud service. Key features include: multi-tenancy (built-in support for hierarchical organizations with organizations, projects, and applications, enabling B2B SaaS multi-tenancy out of the box), authentication (supporting OIDC, OAuth 2.0, SAML 2.0, and machine-to-machine authentication via JWT and client credentials), identity providers (managing users with email, phone, and password credentials, plus social login via Google, GitHub, Azure AD, Apple, GitLab, and custom OIDC providers), multi-factor authentication (TOTP, OTP via SMS and email, hardware security keys via WebAuthn/FIDO2, and push notifications), authorization (Role-Based Access Control with fine-grained permissions, project-level role assignments, and user grants), audit logging (tracking all authentication and authorization events for compliance and security analysis), branding (customizable login pages, emails, and SMS templates with CSS styling and multi-language support), actions (custom JavaScript functions executed during authentication flows for custom logic, claims mapping, and post-authentication steps), API-first design (full REST and gRPC APIs for all operations, enabling automation and infrastructure-as-code), gRPC-based architecture (high-performance inter-service communication), and deployment options (self-hosted via Docker and Kubernetes with CockroachDB backend, or managed cloud service).