Best Authentication & Identity GitHub Repositories

Open Source realtime backend in 1 file

Appwrite® - complete cloud infrastructure for your web, mobile and AI apps. Including Auth, Databases, Storage, Functions, Messaging, Hosting, Realtime and more

Apache Airflow - A platform to programmatically author, schedule, and monitor workflows

Enhanced ChatGPT Clone: Features Agents, MCP, Skills, DeepSeek, Anthropic, AWS, OpenAI, Responses API, Azure, Groq, o1, GPT-5, Mistral, OpenRouter, Vertex AI, Gemini, Artifacts, AI model switching, message search, Code Interpreter, langchain, DALL-E-3, OpenAPI Actions, Functions, Secure Multi-User Auth, Presets, open-source for self-hosting. Active

Open source, composable payments platform | PCI compliant | SaaS and Self-host options | Enables connectivity to multiple payment, payout, fraud, vault and tokenization providers | Uplifts authorization with intelligent routing and revenue recovery | Reduce payment processing costs with cost observability | Reduces payment ops with reconciliation

Composio powers 1000+ toolkits, tool search, context management, authentication, and a sandboxed workbench to help you build AI agents that turn intent into action.

The most comprehensive authentication framework

A reverse proxy that provides authentication with Google, Azure, OpenID Connect and many more identity providers.

🧑‍🚀 Authentication and authorization infrastructure for SaaS and AI apps, built on OIDC and OAuth 2.1 with multi-tenancy, SSO, and RBAC.

Apereo CAS - Identity & Single Sign On for all earthlings and beyond.

Bitwarden mobile apps (Password Manager and Authenticator) for Android.

The most user-friendly OpenID Connect Certified™ and OAuth 2.0 provider that lets users sign in to your applications with passkeys.

The tiniest OpenID Certified™ authorization and authentication server you have ever seen.

Class Variance Authority

Light LDAP implementation

Open-source auth gateway connecting 1500+ SaaS providers to AI agents through SDK, CLI, MCP, HTTP, and OpenAPI.

A high performance and flexible authorization/permission engine built for developers and inspired by Google Zanzibar

Doorkeeper is an OAuth 2 provider for Ruby on Rails / Grape.

Cerbos is an open-core authorization management platform for authorizing every identity and governing every action across applications, gateways, workloads, and AI agents.

An AI Gateway, registry, and proxy that sits in front of any MCP, A2A, or REST/gRPC APIs, exposing a unified endpoint with centralized discovery, guardrails and management. Optimizes Agent & Tool calling, and supports plugins.