# Which Problems Are Solved 1. `oneOf` variant sub-schemas generated from proto `oneof` fields missing `type: "object"`. This causes fumadocs to skip rendering the properties within each variant. Example: https://zitadel.com/docs/reference/api/internal_permission/zitadel.internal_permission.v2.InternalPermissionService.CreateAdministrator [Before](https://zitadel.com/docs/reference/api/internal_permission/zitadel.internal_permission.v2.InternalPermissionService.CreateAdministrator): <img width="977" height="823" alt="Screenshot 2026-03-06 at 09 56 38" src="https://github.com/user-attachments/assets/54ddbbbb-f36b-4a2a-96af-13b3da41de3b" /> [After](https://docs-git-bump-protoc-gen-connect-openapi-version-zitadel.vercel.app/docs/reference/api/internal_permission/zitadel.internal_permission.v2.InternalPermissionService.CreateAdministrator): <img width="964" height="1021" alt="Screenshot 2026-03-06 at 09 56 47" src="https://github.com/user-attachments/assets/a461c4b5-44fe-487b-b4d2-8af47d407d3e" /> 2. missing requestBody for messages with oneOf and path params. Example: https://zitadel.com/docs/reference/api/user/zitadel.user.v2.UserService.UpdateUser [Before](https://zitadel.com/docs/reference/api/user/zitadel.user.v2.UserService.UpdateUser): <img width="994" height="883" alt="Screenshot 2026-03-06 at 09 59 03" src="https://github.com/user-attachments/assets/824f4154-3270-45d7-9af7-a28c7bdc7c44" /> [After](https://docs-git-bump-protoc-gen-connect-openapi-version-zitadel.vercel.app/docs/reference/api/user/zitadel.user.v2.UserService.UpdateUser): <img width="978" height="1293" alt="Screenshot 2026-03-06 at 09 59 25" src="https://github.com/user-attachments/assets/330c1204-ccce-402c-bccb-b27076198dcd" /> (https://github.com/fuma-nama/fumadocs/issues/3063 will also be updated with improved `oneOf` visualization in this case.) # How the Problems Are Solved By fixing `protoc-gen-connect-openapi` to correctly generate the OpenAPI docs. # Additional Changes n/a # Additional Context https://github.com/sudorandom/protoc-gen-connect-openapi/pull/233 https://github.com/sudorandom/protoc-gen-connect-openapi/pull/234
The Identity Infrastructure for Developers
ZITADEL is an open-source identity and access management platform built for teams that need more than basic auth. Whether you're securing a SaaS product, building a B2B platform, or self-hosting a production IAM stack — ZITADEL gives you everything out of the box: SSO, MFA, Passkeys, OIDC, SAML, SCIM, and a battle-tested multi-tenancy model.
No vendor lock-in. No compromise on control. Just a robust, API-first identity platform you can own.
🏡 Website | 💬 Chat | 📋 Docs | 🧑💻 Blog | 📞 Contact
Why ZITADEL
We built ZITADEL to handle the hardest IAM challenges at scale — starting with multi-tenancy.
| ZITADEL | FusionAuth | Keycloak | Auth0/Okta | |
|---|---|---|---|---|
| Open-source | ✅ | ❌ | ✅ | ❌ |
| Self-hostable | ✅ | ✅ | ✅ | ❌ |
| Infrastructure-level tenants | ✅ Instances (High scale) | ✅ Tenants | 🟡 Realms (Scaling limits) | ❌ (Multi-tenant = multi-account) |
| B2B Organizations | ✅ Native & Unlimited | 🟡 via Entity Management | ✅ (Recent addition) | 🟡 (Plan/Account dependent) |
| Full audit trail | ✅ Comprehensive Event Stream* | 🟡 Audit logs | 🟡 Audit logs | 🟡 Audit logs |
| Passkeys (FIDO2) | ✅ | ✅ | ✅ | ✅ |
| Actions / webhooks | ✅ | ✅ | 🟡 via SPI | ✅ |
| API-first (gRPC + REST) | ✅ | 🟡 REST only | 🟡 REST only | 🟡 REST only |
| SaaS + self-host parity | ✅ | ✅ | ➖ N/A | ➖ N/A |
ZITADEL Cloud and self-hosted ZITADEL run the same codebase.
Key differentiators for architects:
- Relational core, event-driven soul — every mutation is written as an immutable event for a complete, API-accessible audit trail. Unlike systems that log only select activities, ZITADEL provides a comprehensive event stream that can be audited or streamed to external systems via Webhooks.
- Strict multi-tenant hierarchy — Identity System → Organizations → Projects, with isolated data and policy scoping at multiple levels
- API-first design — every resource and action is available via connectRPC, gRPC, and HTTP/JSON APIs
- Zero-downtime updates and horizontal scalability without external session stores
Get Started in 3 Minutes
ZITADEL Self-Hosted
# Docker Compose — up and running in under 3 minutes
curl -LO https://raw.githubusercontent.com/zitadel/zitadel/main/deploy/compose/docker-compose.yml \
&& curl -LO https://raw.githubusercontent.com/zitadel/zitadel/main/deploy/compose/.env.example \
&& cp .env.example .env \
&& docker compose up -d --wait
Full deployment guides:
Need professional support for your self-hosted deployment? Contact us.
ZITADEL Cloud (SaaS)
Start for free at zitadel.com — no credit card required. Available in US · EU · AU · CH. Pay-as-you-go pricing.
Integrate with the V2 API
ZITADEL exposes every capability over a typed API. Here's how to create a user with the V2 REST API:
curl -X POST https://$ZITADEL_DOMAIN/v2/users/human \
-H "Authorization: Bearer $ACCESS_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"username": "[email protected]",
"profile": { "givenName": "Alice", "familyName": "Smith" },
"email": { "email": "[email protected]", "sendCode": {} }
}'
Explore the full API reference — including connectRPC and gRPC transports — or jump straight to quickstart examples.
Features
Authentication
- Single Sign On (SSO) · Username/Password · Passkeys (FIDO2 / WebAuthn)
- MFA: OTP, U2F, OTP Email, OTP SMS
- LDAP · Enterprise IdPs and social logins
- OpenID Connect certified · SAML 2.0 · Device authorization
- Machine-to-machine: JWT Profile, PAT, Client Credentials
- Token exchange and impersonation
- Custom sessions for flows beyond OIDC/SAML
- Hosted Login V2
Multi-Tenancy
- Identity brokering with pre-built IdP templates
- Customizable B2B onboarding with self-service for customers
- Delegated role management to third parties
- Domain discovery
Integration
- gRPC, connectRPC, and REST APIs for every resource
- Actions: webhooks, custom code, token enrichment
- RBAC · SCIM 2.0 Server
- Audit log and SOC/SIEM integration
- SDKs and example apps
Self-Service & Admin
- Self-registration with email/phone verification
- Administration Console for orgs and projects
- Custom branding per organization
Deployment
- PostgreSQL (≥ 14) · Zero-downtime updates · High scalability
Track upcoming features on our roadmap and follow our changelog for recent updates.
Showcase
Login V2
Our new, fully customizable login experience — documentation
Adopters & Ecosystem
Used in production by organizations worldwide. See the full Adopters list — and add yours by submitting a pull request.
- SDKs: All supported languages and frameworks
- Examples: Clone and use our examples
How To Contribute
ZITADEL is built in the open and welcoming to contributions of all kinds.
- 📖 Read the Contribution Guide to get started
- 💬 Join the conversation on Discord
- 🐛 Report bugs or request features via GitHub Issues
Contributors
Made with contrib.rocks.
Security
Security policy: SECURITY.md
Vulnerability Disclosure Policy — how to responsibly report security issues.
Technical Advisories are published for major issues that could impact security or stability in production.
License
AGPL-3.0 — see LICENSING.md for the full licensing policy, including Apache 2.0 and MIT exceptions for specific directories.


