# Clerk

> Complete user management platform with authentication, B2B multi-tenancy, and billing for modern applications.

Clerk provides a comprehensive user management solution that goes beyond basic authentication to deliver full-stack auth, user profiles, organization management, and subscription billing. Built for modern web and mobile applications, Clerk enables developers to launch faster with drop-in UI components while maintaining enterprise-grade security and compliance.

- **Pre-built UI Components** offer pixel-perfect, customizable interfaces for sign-up, sign-in, user profiles, organization management, and billing that can be embedded in minutes and styled with any CSS library.

- **Multi-factor Authentication (MFA)** supports authenticator apps, SMS codes, backup codes, and passkeys to enhance account security with self-serve user settings automatically enforced during sign-in.

- **Social Sign-On (SSO)** integrates 20+ social providers including Google, GitHub, and Facebook for high-conversion authentication flows.

- **B2B Organizations** enable multi-tenant SaaS applications with custom roles and permissions, auto-join based on email domains, invitations, and verified domain restrictions.

- **Enterprise Connections** support SAML, OIDC, and EASIE protocols for enterprise authentication requirements.

- **Subscription Billing** allows developers to add recurring revenue without writing payment code, custom UI, or managing webhooks through React components integrated with Stripe.

- **Bot Detection and Fraud Prevention** reduce fraudulent sign-ups with machine learning, disposable email blocking, and email subaddress restrictions.

- **Session Management** handles the full session lifecycle including device tracking, session revocation, custom session tokens, and JWT templates.

- **Framework SDKs** provide native support for Next.js, React, Expo, Astro, Vue, React Router, and more with comprehensive documentation.

- **Database Integrations** connect with Supabase, Convex, and other platforms to leverage Clerk as the source of truth for user data.

To get started, sign up for a free account, install the SDK for your framework, and add Clerk components to your application. The free tier includes 50,000 monthly retained users and 100 organizations with no credit card required.

## Features
- Pre-built UI components for authentication
- Multi-factor authentication (MFA)
- Social sign-on with 20+ providers
- Enterprise SSO (SAML, OIDC)
- B2B organization management
- Custom roles and permissions
- Subscription billing integration
- Bot detection and fraud prevention
- Session management
- Passkey authentication
- Magic links
- Email and SMS one-time passcodes
- User impersonation
- Webhooks for data sync
- Custom JWT templates
- Device tracking and revocation
- SOC 2 Type 2 compliance
- HIPAA compliance
- GDPR compliance

## Integrations
Supabase, Convex, Vercel, Stripe, Next.js, React, Expo, Astro, Vue, React Router, Remix, TanStack React Start, Nuxt, Express, Fastify, Go, Python, Ruby on Rails, Chrome Extension, Android, iOS

## Platforms
ANDROID, IOS, WEB, API, DEVELOPER_SDK

## Pricing
Open Source, Free tier available

## Links
- Website: https://clerk.com
- Documentation: https://clerk.com/docs
- Repository: https://github.com/clerk
- EveryDev.ai: https://www.everydev.ai/tools/clerk