Identity Management

Keycloak and Ory represent two fundamentally different philosophies in open-source identity. Keycloak is a batteries-included monolith — deploy one service, get everything. Ory is a modular microservices ecosystem — deploy only what you need, build your own UI. This comparison covers architecture, features, authorization, deployment, and when each approach wins. At a Glance Keycloak Ory Architecture Monolith (Java/Quarkus) Microservices (Go) License Apache 2.0 Apache 2.0 GitHub Stars ~25,000 (1 repo) ~39,000 (4 repos combined) Built-in UI Yes (admin + login pages) No (headless, API-first) SAML Support Yes (native) Enterprise only (Ory Polis) LDAP Federation Yes No Authorization UMA 2.0 + policies Zanzibar ReBAC (Keto) Multi-tenancy Realms (production-ready) Enterprise/Ory Network only Managed SaaS No official offering Yes (Ory Network) Min Resources ~512 MB RAM (JVM) ~128 MB RAM per service Architecture Keycloak: The Monolith Keycloak is a single Java application that handles everything: OIDC, SAML, user management, admin console, themes, session management, and authorization services. One deployment, one process, one configuration. ...

Keycloak and Authentik are the two most popular open-source identity platforms for self-hosted deployments. Keycloak brings enterprise maturity with 25,000+ GitHub stars and CNCF backing. Authentik brings modern developer experience with 20,000+ stars and rapid community growth. This comparison covers architecture, features, deployment, and when each is the right choice. At a Glance Keycloak Authentik Language Java (Quarkus) Python (Django) + Go outposts License Apache 2.0 MIT (core) + Enterprise License Database PostgreSQL, MySQL, Oracle, MSSQL PostgreSQL only GitHub Stars ~25,000 ~20,200 First Release 2014 2020 (originally “Supervisr”, 2018) Backing Red Hat / IBM, CNCF Incubating Authentik Security (Open Core Ventures) Multi-tenancy Realms (production-ready) Brands (cosmetic) + Tenants (alpha) FAPI Certified Yes (1.0 Advanced, all 8 profiles) No Min Resources 2 CPU / 2 GB RAM 2 CPU / 2 GB RAM Latest Version 26.x 2025.12.4 Architecture Keycloak Keycloak runs on the Quarkus framework (Java). A single binary handles all protocol endpoints (OIDC, SAML, LDAP), admin console, and account console. It stores sessions and configuration in an embedded Infinispan cache with database persistence. ...

Keycloak is the established open-source IAM platform with 41,000+ GitHub stars and CNCF backing. Zitadel is the challenger — a Go-based, event-sourced platform growing rapidly at 13,000+ stars. This comparison covers architecture, features, operations, and when each is the better choice. At a Glance Keycloak Zitadel Language Java (Quarkus) Go License Apache 2.0 AGPL-3.0 (v3+) GitHub Stars 41,000+ 13,000+ CNCF Status Incubating Not a CNCF project First Release 2014 2019 Maintainer Red Hat CAOS AG (Switzerland) Architecture Stateful (Infinispan cache) Stateless (event-sourced) Database PostgreSQL, MySQL, MariaDB, Oracle, MSSQL PostgreSQL only Cloud Offering Red Hat Build of Keycloak (subscription) Zitadel Cloud (free tier: 100 DAU) Architecture Keycloak Keycloak runs on Java/Quarkus with Infinispan for distributed session caching. A production deployment requires Keycloak nodes + an external database + Infinispan cluster configuration. Nodes are stateful — they hold session data in memory, requiring sticky sessions for optimal performance. ...

The redirect_uri mismatch is the second most common OAuth error after invalid_grant. Every OAuth provider requires that the redirect URI in your request exactly matches a pre-registered value — and “exactly” means character-for-character, including trailing slashes, ports, and protocol. This guide covers every cause and provider-specific fix. Quick Diagnostic: Which Provider Error Are You Seeing? Error Message Provider Jump To Invalid parameter: redirect_uri Keycloak Keycloak Callback URL mismatch Auth0 Auth0 redirect_uri must be a Login redirect URI in the client app settings Okta Okta AADSTS50011 Azure AD / Entra ID Azure AD Error 400: redirect_uri_mismatch Google Google The redirection URI provided does not match a pre-registered value ForgeRock AM ForgeRock redirect_mismatch AWS Cognito AWS Cognito Every Cause of redirect_uri Mismatch Before checking provider-specific fixes, work through this checklist. Most mismatches fall into one of these 10 categories: ...

Keycloak session errors are the most common source of unexpected logouts. Your application works perfectly in development, then users report being logged out randomly in production. The token refresh returns invalid_grant with a cryptic error_description like “Session not active” — and the Keycloak admin console shows no obvious misconfiguration. This guide explains every Keycloak session type, how their timeouts interact, and how to fix each session error. Quick Diagnostic: Which Error Are You Seeing? error_description Jump To Session not active SSO Session Expired Token is not active Refresh Token Expired Session doesn't have required client Cache Eviction Offline session not active Offline Session Expired Client session not active Client Session Expired authentication_expired in redirect URL Authentication Session Timeout All of these appear as invalid_grant in the OAuth error response: ...

Keycloak LDAP integration fails silently with generic error messages. The admin console shows “Connection refused” or “Test authentication failed” without revealing the actual cause. This guide catalogs every Keycloak LDAP error with exact log messages, Active Directory sub-codes, and fix commands. For initial LDAP setup instructions, see Keycloak User Federation with LDAP and Active Directory. Quick Diagnostic: Which Error Are You Seeing? Admin Console / Log Message Jump To Connection refused Connection Errors LDAP: error code 49 Bind / Authentication Errors SSLHandshakeException: PKIX path building failed TLS / SSL Errors Test Connection passes, Test Authentication fails TLS / SSL Errors PartialResultException: Referral Search and Sync Errors SizeLimitExceededException Search and Sync Errors Sync shows 0 imported, 0 updated Search and Sync Errors LDAP: error code 53 - WILL_NOT_PERFORM Password Change Errors Groups sync but clicking a group raises errors Group Mapper Errors Connection Errors Connection Refused javax.naming.CommunicationException: ldap.example.com:389 [Root exception is java.net.ConnectException: Connection refused] Causes (in order of likelihood): ...

CORS errors are the most frustrating errors in OAuth development. The browser blocks your request, the error message is generic, and the actual cause could be any of 8+ different scenarios. This guide covers every CORS error you’ll encounter in OAuth 2.0 and OIDC flows, with exact browser error messages and provider-specific fixes. Quick Diagnostic: Which Error Are You Seeing? Browser Console Error Jump To No 'Access-Control-Allow-Origin' header on /authorize Scenario 1: Calling /authorize via fetch No 'Access-Control-Allow-Origin' header on /token Scenario 2: Token endpoint CORS AADSTS9002327: Cross-origin token redemption Scenario 3: Azure AD SPA registration CORS error only after session timeout Scenario 4: Keycloak error response bug wildcard '*' when credentials mode is 'include' Scenario 5: Wildcard with credentials Response to preflight request doesn't pass Scenario 6: Preflight failures CORS error on /revoke endpoint Scenario 7: Token revocation Everything works except in production Scenario 8: Proxy/CDN stripping headers Which OAuth Endpoints Support CORS? Before debugging, know which endpoints are designed to accept cross-origin requests: ...

The invalid_grant error is the most common and most confusing OAuth error. It appears during token exchange or refresh token requests, but the same error code covers 18+ different root causes. This guide catalogs every known cause with provider-specific error messages and exact debugging commands. Quick Diagnostic Checklist When you encounter invalid_grant, work through this list in order: Read the error_description — most providers include specific details Is the authorization code fresh? — Exchange immediately, never retry with the same code Does redirect_uri match exactly? — Check trailing slashes, protocol, port Is the PKCE code_verifier correct? — Verify the stored value matches the challenge Are client credentials correct? — Verify client_id and client_secret for the right environment Is the refresh token still valid? — Check idle timeout, absolute lifetime, rotation Has the user’s password changed? — Password resets invalidate tokens on most providers Is the server clock in sync? — Run ntpdate -q pool.ntp.org Check IdP logs — Keycloak events, Auth0 logs, Azure AD sign-in logs Is Google app in “Testing” mode? — Tokens expire after exactly 7 days All Causes of invalid_grant Authorization Code Issues Expired code — Authorization codes have short lifetimes: ...

The Model Context Protocol (MCP) defines how AI agents connect to external tools and data sources. When an MCP client (like Claude Desktop or a custom AI agent) needs to access a protected MCP server, it uses OAuth 2.1 — not OAuth 2.0 — as the authorization mechanism. This article explains exactly how MCP authentication works, what makes it different from traditional OAuth, and which identity providers actually support it. ...

OAuth 2.1 is an updated version of the OAuth 2.0 authorization framework that includes enhancements for security and usability. These updates address common vulnerabilities and improve the overall security posture of applications using OAuth for authorization. What is OAuth 2.1? OAuth 2.1 builds upon OAuth 2.0 by introducing new features such as Proof Key for Code Exchange (PKCE) for all public clients and Token Binding to enhance security. These changes aim to protect against authorization code interception attacks and ensure that tokens are used securely. ...

Why This Matters Now With the increasing emphasis on digital transformation and cloud adoption, the need for robust identity management solutions has never been more critical. The recent surge in remote work and multi-cloud environments has exacerbated the challenge of managing user identities across various platforms. As a result, understanding the nuances between SAML and SSO has become essential for IAM engineers and developers. Misconfigurations or misunderstandings can lead to significant security risks, making it crucial to get these protocols right. ...

Choosing the right JWT library can make or break your authentication implementation. A poorly maintained library might leave you vulnerable to known attacks like algorithm confusion or token forgery, while a well-designed one handles signature verification, claim validation, and key management out of the box. This guide evaluates the best JWT libraries across eight programming languages, comparing them on algorithm support, API design, maintenance activity, and real-world adoption. Whether you are building a microservice in Go, a REST API in Python, or a full-stack application in TypeScript, you will find the right tool here. ...

The IAM (Identity and Access Management) market offers dozens of platforms ranging from open source solutions to enterprise SaaS products. This guide compares the major IAM platforms across features, pricing, deployment models, and use cases to help you choose the right solution. Quick Comparison Matrix Platform Type Best For Pricing Model OIDC SAML MFA Social Login Keycloak Open Source Self-hosted control Free (infra costs) Yes Yes Yes Yes Auth0 SaaS Developer experience Per MAU Yes Yes Yes Yes Okta SaaS Enterprise workforce Per user/month Yes Yes Yes Yes ForgeRock/Ping Enterprise Large enterprise Custom contract Yes Yes Yes Yes AWS Cognito Cloud AWS ecosystem Per MAU Yes Yes Yes Yes Azure Entra ID Cloud Microsoft ecosystem Per user/month Yes Yes Yes Limited Head-to-Head Comparisons These detailed comparison articles analyze specific platform matchups with pricing, features, and real-world decision criteria. ...

Choosing an Identity and Access Management (IAM) platform is one of the most consequential infrastructure decisions a development team can make. The right choice secures your users and simplifies your architecture; the wrong one creates years of technical debt. In 2026, the open source IAM landscape is more mature and more competitive than ever, with options ranging from full-featured enterprise platforms to lightweight, developer-first libraries. This guide compares the top 10 open source IAM solutions across features, community health, deployment complexity, and ideal use cases. Whether you are building a SaaS product, securing internal tools, or replacing a legacy identity provider, this comparison will help you make an informed decision. ...

Keycloak is the most widely adopted open-source Identity and Access Management (IAM) platform in the world. Backed by Red Hat and used by organizations ranging from startups to Fortune 500 companies, it provides enterprise-grade authentication and authorization without per-user licensing fees. This guide covers everything you need to know about Keycloak – from your first Docker container to a production-ready, highly available cluster. Whether you are evaluating Keycloak for a new project, migrating from a commercial IAM vendor, or looking to deepen your expertise, this page links to every Keycloak resource on this site and provides the context to navigate them effectively. If you are completely new, start with Getting Started with Keycloak and come back here as a reference. ...

Clone the companion repo: IAMDevBox/forgerock-gitops-argocd — production-ready ArgoCD App-of-Apps template with ForgeRock AM/DS/IDM configs, Sealed Secrets workflow, and Kustomize overlays for dev/prod environments. GitOps for ForgeRock is a practice that uses Git as the single source of truth to manage and deploy identity configuration changes. This approach leverages the principles of GitOps, which emphasize declarative infrastructure and continuous delivery, to streamline identity management processes. By integrating GitOps with ArgoCD, you can automate the deployment of ForgeRock configurations, ensuring consistency and reducing the risk of human error. ...

Keycloak Admin REST API is a set of endpoints that allows administrators to manage Keycloak realms, users, clients, and other resources programmatically. This API provides a powerful way to integrate Keycloak into your existing systems and automate repetitive tasks. What is Keycloak Admin REST API? Keycloak Admin REST API is a set of endpoints that allows administrators to manage Keycloak realms, users, clients, and other resources programmatically. This API provides a powerful way to integrate Keycloak into your existing systems and automate repetitive tasks. ...

PingFederate SAML configuration involves setting up Security Assertion Markup Language (SAML) for secure enterprise federation, enabling single sign-on (SSO) between identity providers (IdPs) and service providers (SPs). This guide will walk you through the process, including common pitfalls and best practices. What is SAML? SAML is an XML-based standard for exchanging authentication and authorization data between parties, particularly between an identity provider and a service provider. It allows users to log into multiple applications with a single set of credentials. ...

ForgeRock Infrastructure as Code allows you to manage and provision ForgeRock Identity Management resources using declarative configuration files. This approach brings the benefits of Infrastructure as Code (IaC) to identity management, enabling consistent deployments, easier maintenance, and improved security. What is ForgeRock Infrastructure as Code? ForgeRock Infrastructure as Code leverages the Terraform provider to automate the deployment and management of ForgeRock Identity Management components. By defining your identity management setup in Terraform configuration files, you can ensure consistency across environments and simplify the process of making changes. ...

Custom authentication flows in Keycloak allow you to define unique login processes tailored to specific application needs. Whether you need multi-factor authentication, social logins, or custom policies, Keycloak provides the flexibility to create these journeys with ease. In this post, we’ll walk through building custom authentication flows, common pitfalls, and best practices to ensure your login processes are both secure and efficient. What is Keycloak Custom Authentication Flows? Custom authentication flows in Keycloak let you define unique login processes tailored to specific application needs. Instead of relying on the default flows, you can create flows that include additional steps, such as OTP verification, social logins, or custom policies. ...