ZITADEL is an open-source identity and access management platform designed to simplify user authentication, authorization, and multi-tenant user management for both B2B and CIAM scenarios. Built in Go with a PostgreSQL backend, it provides a complete turnkey solution that combines the ease of setup of Auth0 with the openness and control of Keycloak. ZITADEL is ideal for developers and DevOps teams building applications requiring SSO, passkey-based login, SCIM provisioning, or complex role-based access control across multiple organizations. With its API-first design and event-sourced audit trail, it ensures compliance, scalability, and extensibility without requiring deep expertise in identity protocols.
Unlike traditional identity providers that force compromises between features and complexity, ZITADEL delivers enterprise-grade capabilities—including FIDO2 passkeys, SAML 2.0, LDAP integration, and SCIM 2.0—out of the box. Its self-hosted option gives full control over data residency and compliance, while its cloud version offers a managed SaaS experience with the same feature set. Whether you’re securing a multi-tenant SaaS product or managing customer identities at scale, ZITADEL eliminates the need to build and maintain custom authentication systems.
What You Get
- Multi-tenancy with team management - Manage separate organizations, projects, and user roles within a single ZITADEL instance; each tenant has isolated users, applications, and configurations.
- OpenID Connect & OAuth2.x certified - Fully compliant with OpenID Connect certification, supporting Authorization Code Flow (PKCE), Client Credentials, and token exchange for secure API access.
- SAML 2.0 and LDAP integration - Connect to existing enterprise identity providers via SAML metadata or LDAP directories for seamless single sign-on.
- FIDO2/Passkeys support - Enable passwordless login using WebAuthN-compatible devices like YubiKeys, smartphones, or built-in platform authenticators.
- SCIM 2.0 Server - Automate user provisioning and deprovisioning in connected applications using the System for Cross-domain Identity Management standard.
- Multi-factor authentication (MFA) - Support for OTP, SMS OTP, email OTP, and U2F/FIDO2 devices with configurable enforcement policies per organization.
- Actions and webhooks - Execute custom logic on identity events (e.g., user registration, login) via HTTP webhooks or integrations with external APIs.
- Self-service portal - Allow end-users and administrators to manage profiles, MFA devices, and organization settings without developer intervention.
- Audit trail with event sourcing - Immutable, detailed logs of all user and system events for compliance (SOC 2, GDPR) with real-time export to SIEM tools.
- Hosted and customizable login UI - Use ZITADEL’s pre-built login pages or fully customize the UI with your branding and custom flows.
- Zero-downtime updates - Upgrade ZITADEL without service interruption using rolling deployments and database migration support.
- Machine-to-machine auth - Authenticate services using JWT profiles, Personal Access Tokens (PAT), or OAuth2 Client Credentials without user interaction.
Common Use Cases
- Building a multi-tenant SaaS dashboard with real-time analytics - Use ZITADEL to isolate customer data per tenant, assign roles via SCIM, and enable SSO using their existing Azure AD or Okta identity provider.
- Creating a mobile-first e-commerce platform with 10k+ SKUs - Implement passkey-based login for users across devices, integrate with existing LDAP directories for B2B buyers, and enforce MFA for admin access.
- Problem: Managing user identities across 50+ client organizations → Solution: ZITADEL’s multi-tenancy and identity brokering - Onboard new clients by importing SAML metadata or LDAP configs without custom code, and automatically provision users via SCIM to connected apps.
- DevOps teams managing microservices across multiple cloud providers - Use ZITADEL’s API to programmatically create service users, issue JWTs for internal services, and audit every token request across AWS, GCP, and Azure.
Under The Hood
Zitadel is a comprehensive identity and access management platform designed to provide authentication, authorization, and API governance within a modular, multi-language architecture. It combines backend services built in Go with frontend applications developed using TypeScript and Next.js, enabling a well-defined separation of concerns across its system layers.
Architecture
Zitadel adopts a modular, multi-layered architecture that emphasizes clear boundaries between components and services.
- The system uses a monorepo structure to manage diverse applications including authentication, admin interfaces, and documentation.
- Services are organized around identity management, API handling, and user-facing UIs with distinct modules for each concern.
- A service-oriented design allows for extensibility and integration across different system components.
Tech Stack
The project leverages a polyglot approach with Go for backend services and TypeScript/Next.js for frontend experiences.
- Core backend services are implemented in Go, while the frontend is built using React-based components and Next.js for rendering.
- Key tools include Nx for monorepo management, pnpm for package handling, and Buf for protocol buffer support.
- Testing is handled through Playwright, Vitest, and Cypress to ensure robust end-to-end and unit validation.
Code Quality
The codebase reflects a mature approach to testing with extensive coverage in acceptance and integration layers.
- Error handling is consistently applied across modules, using structured try/catch patterns to maintain system resilience.
- Code linting and CI/CD pipelines are configured, supporting a clean and maintainable codebase.
- While style and convention adherence are generally solid, some technical debt remains in the form of skipped tests and placeholder implementations.
What Makes It Unique
Zitadel distinguishes itself through its unified approach to identity and access management in a modular, multi-language ecosystem.
- It seamlessly integrates authentication, authorization, and API governance into a cohesive platform with strong security standards.
- Its modular architecture enables broad extensibility and supports diverse integration scenarios without sacrificing performance or usability.
- The combination of Go-based backend services with TypeScript/Next.js frontend components allows for scalable and maintainable development.