Web Application Authentication Libraries

Kratos is a centralized identity and access management server designed to handle user registration, authentication, and profile management. It functions as an identity flow orchestrator, managing the state and security of authentication processes across web, mobile, and command-line interfaces. The system provides a standards-compliant authorization server that issues tokens and manages delegated access for third-party applications and internal services, supporting multi-factor authentication and custom identity schemas to secure user accounts. The project distinguishes itself through a headless architecture that decouples identity flows from the user interface. By providing JSON-based API responses, it allows developers to build custom authentication experiences for any platform. It also implements a relationship-based access control model, which evaluates permissions by traversing a directed graph of relationships between subjects and objects. This approach enables fine-grained access control, allowing developers to model complex authorization requirements and verify user permissions dynamically across distributed software systems. Beyond core identity and authorization, the platform includes extensive developer tooling, such as language-specific client libraries and a command-line interface for managing projects and authentication sessions. It supports lifecycle extensions through hooks, allowing custom business logic to trigger after specific identity events. The system also provides robust session management using cryptographically signed tokens that track authentication assurance levels, ensuring consistent security across disparate application boundaries.

Logto is an open-source identity provider that serves as a centralized authentication and authorization server for web, mobile, and command-line applications. It implements the OpenID Connect and OAuth 2.1 standards to handle secure user sign-in and the issuance of identity tokens. The platform is specifically designed as a multi-tenant authentication framework for software-as-a-service environments, featuring built-in organization management and tenant isolation. It includes an enterprise single sign-on gateway to integrate external identity providers and supports role-based access control to manage permissions through organizational hierarchies. The system covers identity and access management through user onboarding flows, multi-factor authentication, and custom sign-in interfaces. It also provides tools for organization-level membership management and the automation of user and role provisioning. The software is distributed via container images to ensure consistent deployment across different computing environments.

Authelia is a centralized identity and access management server designed to secure web applications through unified authentication and authorization. It functions as an identity authority that enables single sign-on across diverse platforms, allowing users to access multiple services with a single set of credentials. By acting as a standards-compliant provider, it facilitates secure identity propagation and token issuance for client applications. The platform distinguishes itself through its ability to integrate directly with web gateways as a reverse proxy authentication middleware, intercepting requests to validate user identity before granting access to protected resources. It enforces granular access control policies and provides robust multi-factor authentication, supporting various verification methods such as hardware security keys, mobile push notifications, and time-based one-time passwords. To maintain consistency across distributed environments, it utilizes stateless session management via encrypted cookies. Authelia offers a flexible integration surface, featuring a pluggable backend that supports multiple external directory services like LDAP alongside internal database options. Its configuration is managed through a declarative, version-controlled YAML schema, which can be further automated using environment variables. The project provides comprehensive command-line tooling for policy validation and configuration management, with native support for deployment in containerized and orchestrated environments.

This project is an open-source identity provider and single sign-on platform that centralizes user authentication for multiple web applications and services. It functions as a multi-protocol authentication gateway, verifying user identities and issuing tokens through the CAS protocol as well as industry standards including SAML, OAuth2, and OpenID Connect. The system acts as a federated identity server, allowing authentication to be delegated to external third-party or corporate identity providers. It distinguishes itself through identity attribute governance, which manages which specific user profile data and permissions are released to connected applications while collecting necessary user consent. The platform covers broad capability areas including enterprise access control, multifactor authentication enforcement via hardware keys or mobile apps, and comprehensive account lifecycle management. It also provides tools for centralized security auditing, system performance monitoring, and the administration of client application registrations.

This project is a cloud-native identity and access management platform designed to centralize authentication, authorization, and identity lifecycle management. It functions as a standards-compliant OpenID Connect authorization server, providing secure session management and token issuance for web, mobile, and device-based applications. The platform is built to handle complex identity requirements through stateless token authentication and support for modern passwordless methods, including biometrics and hardware keys. What distinguishes this platform is its native support for multi-tenant environments, allowing organizations to manage isolated identity configurations, custom branding, and federated login policies within a single instance. It features a programmable authentication engine that enables developers to inject custom business logic into login and token generation flows using event-driven scripts. This extensibility is complemented by robust B2B capabilities, such as domain-based user routing and project-level access delegation, which facilitate secure collaboration across different business entities. The platform covers a broad capability surface, including comprehensive audit trails, external log streaming, and administrative resource management APIs. It supports diverse integration strategies, ranging from social logins and external identity brokering to directory service synchronization. The system is designed for high availability and scalability, utilizing event-sourced state persistence and container-orchestrated deployment patterns to ensure reliable operation in production environments. The software is distributed as container images, with support for automated deployment and zero-downtime updates through a phase-separated lifecycle management approach.

Casdoor is a centralized identity and access management platform that functions as an OAuth 2.0 authorization server. It provides a comprehensive suite of services for managing user identities, authentication sessions, and access policies across both web and machine-to-machine applications. Built with a decoupled frontend-backend architecture in Go, the platform supports high-concurrency environments and offers a web-based management interface for administrative tasks. The platform distinguishes itself through its extensive support for federated identity management, allowing integration with external providers via OIDC, SAML, and LDAP. It enforces granular security through role-based access control, scope-based permission validation, and hardware-backed authentication methods like WebAuthn. Beyond standard identity services, it includes specialized infrastructure for managing AI agent lifecycles, monitoring agent traffic, and securing tool access through delegated authentication. The system provides a broad capability surface that includes observability and audit logging, event-driven webhook notifications, and automated session management. It also offers developer-focused tools such as CLI-based authentication flows, secure token storage, and software development kits for integrating identity verification into external services. The platform is designed for flexible deployment, supporting configuration via JSON-based data initialization and providing APIs for querying system status and version information.

django-allauth is a comprehensive authentication framework for Django applications that manages user registration, account ownership verification, and secure login processes. It provides a system for handling the entire user account lifecycle, including the ability to define custom signup fields and implement identity verification. The project distinguishes itself by providing a suite of OAuth and SAML integrations for social account authentication and the capability to act as an OpenID Connect identity provider. It further supports decoupled architectures through a token-based headless authentication API with dynamic specifications. The framework includes security layers for multi-factor authentication, brute-force attack prevention via request rate limiting, and account enumeration prevention. It also features an adapter pattern for customizing authentication logic and a signal-driven system for tracking authentication events.

Tinyauth is an authentication middleware service and identity provider that verifies user identities to grant system access. It operates as a standalone server or as an authentication gateway, utilizing a reverse proxy model to intercept requests and validate credentials before traffic reaches protected backend services. The project functions as an OpenID Connect provider for single sign-on experiences and an OAuth 2.0 gateway that delegates verification to external providers such as Google and GitHub. It also acts as an LDAP authentication server, allowing for centralized user management and group-based authorization through external directory integration. The system covers a broad range of access control capabilities, including path-based and IP-based filtering, as well as identity-based restrictions. Security is further enhanced through multi-factor authentication using time-based one-time passwords and the use of bcrypt for secure credential storage. The server is bootstrapped using environment variables to facilitate containerized deployments.

Hanko is an open-source identity provider and customer identity and access management system. It serves as a passkey authentication service and an OAuth and SAML SSO gateway, allowing applications to authenticate users and issue tokens via standard identity protocols. The project distinguishes itself through a strong focus on passwordless access using WebAuthn-based passkeys and email-based passcodes. It provides framework-agnostic authentication interfaces as customizable web components that can be embedded directly into web applications to handle login, registration, and profile management. The platform covers a broad range of identity capabilities, including multi-factor authentication, social login integrations, and enterprise single sign-on. It also provides comprehensive session management, role-based and attribute-based access control, and tools for synchronizing identity data via webhooks and external database integrations. The service is integrated into applications through client and server-side SDKs and supports custom branded domain mapping.

Keycloak is an open-source identity and access management server that provides a centralized platform for user authentication, authorization, and identity federation. It functions as a standards-compliant identity provider, utilizing a centralized engine to validate credentials and issue cryptographically signed tokens based on industry-standard protocols like OpenID Connect and SAML. This enables organizations to secure diverse applications and services through a unified authentication layer. The platform distinguishes itself through its cloud-native orchestration and high-availability capabilities. It utilizes a Kubernetes-native operator and control loop pattern to automate the deployment, scaling, and lifecycle management of identity services within containerized environments. To ensure resilience and continuous uptime, the server employs a distributed data grid that synchronizes session state and cache entries across multiple nodes, preventing service interruptions during hardware or network failures. Beyond its core identity functions, the system offers a modular plugin architecture that allows developers to extend server functionality through custom interfaces for authentication, storage, and user federation. It also includes a theme engine for server-side template rendering, enabling the customization of login screens and user-facing pages to match specific branding requirements. Administrative tasks, including the management of realms, users, and security policies, can be performed through centralized tools or programmatically via a REST API. The project provides comprehensive documentation, including guides for server configuration, performance monitoring, and version migration. Installations are supported across various environments, ranging from standalone archives to containerized deployments managed by automated controllers.

SuperTokens Core is an open-source, self-hosted authentication and identity management platform designed for deployment within private infrastructure. It provides a comprehensive suite for managing user accounts, roles, and secure authentication flows, utilizing a modular, recipe-based architecture that allows developers to enable specific security features without modifying the core codebase. The platform distinguishes itself through its robust multi-tenancy capabilities, which allow for the logical or physical isolation of user records and configuration settings across different organizational environments. It employs a claims-based session management model that uses cryptographically signed tokens to enable stateless authorization, alongside an event-driven hook system that triggers custom business logic during authentication lifecycle events. The system covers a broad capability surface, including diverse authentication methods such as passwordless flows, social and enterprise single sign-on, and hardware-backed passkey support. It also integrates advanced security features like threat detection, multi-factor authentication enforcement, and granular role-based access control, while providing tools for session monitoring, request tracing, and user data migration from legacy systems. The project is designed to be run as a containerized service, offering horizontal scalability to handle varying traffic loads. Detailed documentation and administrative interfaces are available to assist with environment configuration, UI theming, and the integration of custom authentication logic.

Pocket ID is a self-hosted OpenID Connect (OIDC) identity provider that replaces traditional passwords with passkey-based authentication using WebAuthn public-key cryptography. It runs as a standalone service on user-managed infrastructure, eliminating shared secrets entirely by authenticating users through passkeys instead of passwords. The project distinguishes itself through security-hardened deployment patterns, including distroless container images, non-root user execution, and read-only root filesystems to reduce the attack surface. It supports configurable token signing algorithms (RSA, ECDSA, or EdDSA) with user-defined key sizes and rotation capabilities, along with wildcard callback URL matching and user group access restrictions for OIDC clients. Beyond core authentication, Pocket ID provides user and group management through LDAP directory synchronization, a REST API for automation, and flexible registration workflows including manual creation, invitation links, or open registration. It includes audit logging for security monitoring, anonymous usage telemetry for instance counting, and email notifications for sign-ins from unrecognized devices. The project is deployed as a containerized service with documented setup guides for integrating with third-party applications.

Kanidm is a centralized identity management server designed to handle authentication, authorization, and directory services across distributed infrastructure. It provides a comprehensive framework for managing human and service accounts, utilizing a schema-driven database to store identity records, group memberships, and system attributes. The platform supports a wide range of authentication methods, including passkeys, passwords, and standard protocols like OAuth2, OIDC, LDAP, and RADIUS. The system distinguishes itself through a granular access control engine that enforces security policies based on user, group, and resource attributes. It incorporates advanced security features such as privilege access mode enforcement, which requires reauthentication for sensitive operations, and high-privilege group tainting to prevent lateral movement. Administrators can delegate management tasks for specific entries or groups, ensuring that permissions remain tightly scoped while maintaining operational flexibility. Beyond core identity functions, the platform includes robust tools for system maintenance, including automated backup scheduling, database consistency verification, and multi-node replication to ensure high availability. It also provides deep integration with host operating systems through pluggable authentication modules and supports infrastructure access provisioning by managing SSH keys and POSIX attributes. The project provides a suite of command-line utilities for administrative tasks, session management, and server configuration. Documentation and installation resources are available to guide the deployment of the server and its associated client tools.

Hydra is a headless identity server that functions as a certified OAuth2 and OpenID Connect provider. It is designed as an authentication engine that manages authorization handshakes and token lifecycles while remaining decoupled from the user interface. The project distinguishes itself through a headless architecture, allowing external management of login and consent flows. It provides specialized capabilities for dynamic client registration, JSON Web Token issuance, and a system for rotating encryption secrets without service downtime. The system covers a broad range of identity operations, including the orchestration of authentication sequences, identity provisioning, and token lifecycle management. It supports state persistence via adapters for PostgreSQL, MySQL, and CockroachDB, and includes observability tools through Prometheus-compatible metrics and distributed tracing. Administrative access is managed through port-based API isolation to separate privileged endpoints from public-facing protocol APIs.

Sa-Token is a Java-based authentication and authorization framework designed to manage user sessions, permissions, and identity verification within web applications and microservice architectures. It provides a centralized security layer that enforces access control policies and identity validation across distributed service environments and API gateways. The framework distinguishes itself through its support for cross-domain single sign-on and its ability to function as an OAuth2 identity provider. It manages user session lifecycles by applying configurable rules for single or multi-login requirements and synchronizes authentication states across multiple servers and independent application instances using external, persistent storage. Beyond core identity management, the project covers a broad range of security capabilities including role-based access control and interceptor-based enforcement. It integrates with diverse web frameworks through an adapter-based approach, allowing for consistent security enforcement regardless of the underlying application architecture.

Appwrite is a backend-as-a-service platform that provides a unified development environment for building full-stack applications. It integrates essential infrastructure components—including authentication, databases, storage, and serverless functions—into a single, centralized interface to simplify application development and resource management. The platform distinguishes itself through a container-based microservices architecture that ensures consistent execution across diverse infrastructure. It features a versatile connectivity layer that links frontend applications with third-party services, databases, and external APIs through standardized interfaces. Developers can manage and automate the configuration of these backend resources using infrastructure-as-code tools, while granular role-based access control enforces security policies across all platform resources and API endpoints. Beyond its core services, the platform offers a broad capability surface that includes cross-platform data synchronization, event-driven webhooks, and comprehensive billing and usage monitoring. It supports extensive integrations for AI utilities, payment processing, messaging, and logging, allowing developers to extend application functionality through modular, event-driven workflows. The platform is designed for both managed and self-hosted deployments, providing tools for production environment optimization, data migration, and custom domain configuration.

OpenCloud is a self-hosted platform for synchronizing files across devices and sharing them with team members through collaborative spaces and access controls. It enables users to sync files between a server and local desktop and mobile clients, manage files and folders, and share content with internal and external contributors via permission-based links and file drops. The platform integrates an embedded OpenID Connect identity provider for authentication and supports external identity providers. It stores all data and metadata directly on the filesystem, eliminating the need for a separate database. Users can edit office documents directly in a browser with real-time collaboration through the WOPI protocol. Team collaboration is organized in dedicated shared spaces with role-based permissions and administrative settings. Additional capabilities include managing team spaces, configuring access permissions, and setting system-wide policies. The architecture provides token-based share access and client-server file synchronization for incremental updates and conflict resolution.

This project is a modular authentication framework designed to manage user identity, session tracking, and access control across web applications. It provides a unified solution for handling email-based credentials and social identity federation, allowing developers to implement secure login and registration flows that maintain consistent user states across client and server environments. The system utilizes a plugin-based architecture and middleware-driven request interception to allow for the extension of core authentication logic. It features type-safe schema generation, which derives database structures and API contracts directly from configuration, and employs a database-agnostic adapter pattern to interface with various storage backends. These capabilities enable the creation of custom security logic and database schemas that adapt to specific application requirements. To support development, the framework includes integrated tooling that provides context-aware knowledge to coding assistants. By configuring agent skills and connecting documentation through standardized protocols, developers can automate the implementation of authentication patterns while ensuring adherence to established conventions and security standards.