Logto is an open-source identity and access management platform designed for developers building SaaS and AI applications. It eliminates the complexity of implementing authentication, authorization, and user management by providing pre-built, production-ready flows for email/password, social login, MFA, SSO, and multi-tenancy. Built on OIDC, OAuth 2.1, and SAML, it replaces fragmented solutions like Auth0, Cognito, or Firebase with a unified, developer-first system that scales from startups to enterprises.
Logto supports deployment via Docker, Node.js, or its fully managed cloud service, and integrates with 30+ frameworks including React, Next.js, Go, Python, and Vue. Its architecture includes a Management API, customizable UIs, and native support for Model Context Protocol and agent-based AI systems. With built-in RBAC, impersonation, personal access tokens, and IdP capabilities, it provides a complete identity stack without vendor lock-in.
What You Get
- OIDC and OAuth 2.1 Support - Full implementation of modern identity protocols with token-based authentication, authorization flows, and standard-compliant token issuance for web, mobile, and M2M applications.
- Multi-tenancy with RBAC - Built-in organization and tenant isolation with role-based access control for global and per-tenant resources, enabling SaaS applications to manage multiple customers securely.
- Enterprise SSO (SAML & IdP) - Connect to Okta, Entra ID, or any SAML-based identity provider with pre-built connectors and just-in-time provisioning for seamless user onboarding.
- Passwordless Authentication - Support for email and SMS one-time codes, eliminating passwords while maintaining user-friendly sign-in experiences.
- Multi-Factor Authentication (MFA) - Supports WebAuthn (passkeys), authenticator apps (TOTP), and backup codes with configurable enforcement policies per tenant or user.
- Machine-to-Machine (M2M) Authentication - Secure API-to-API communication using client credentials flow, with support for personal access tokens (PATs) for scripts and automation pipelines.
- User Impersonation - Admins can safely impersonate end users to troubleshoot issues without requiring passwords or session hijacking.
- Management API - RESTful API for programmatic user, role, and tenant management, enabling automation and integration with CI/CD, HR systems, or custom dashboards.
- No-Code Auth UI - Pre-built, customizable sign-in and sign-up interfaces that work out-of-the-box with zero frontend development required.
- 30+ Framework SDKs - Official libraries for React, Next.js, Vue, Angular, Flutter, Go, Python, .NET Core, SvelteKit, and Vanilla JS for rapid integration.
Common Use Cases
- Building a multi-tenant SaaS platform - A B2B software company uses Logto to manage separate tenant environments, enforce RBAC per customer, and integrate SAML SSO for enterprise clients without custom auth code.
- Securing AI agent ecosystems - An AI startup uses Logto’s M2M authentication and Model Context Protocol support to secure communication between LLM agents, APIs, and external tools.
- Replacing Auth0 or Firebase Auth - A mid-sized startup migrates from proprietary auth services to Logto to avoid vendor lock-in, reduce costs, and gain full control over user data and flows.
- Enabling passwordless onboarding for mobile apps - A fintech app integrates Logto’s email/SMS passwordless flows to reduce friction during user signup and improve conversion rates on iOS and Android.
Under The Hood
Architecture
- Monorepo structure with well-defined packages for core logic, CLI, connectors, and UI, enforcing clear separation of concerns
- Dependency injection via a custom service container enables loose coupling and testability through interface-based abstractions
- REST API uses middleware pipelines to isolate authentication, validation, and rate limiting concerns
- Admin console leverages React context and component composition to maintain separation from backend services
- Integration tests use Docker Compose to simulate production environments with isolated data and health-checked services
Tech Stack
- Node.js 22 with pnpm monorepo and tsup/Vite for efficient TypeScript bundling and development
- PostgreSQL with built-in migrations and Redis for caching and session management
- React 18 frontend with routing, internationalization, and WebAuthn for authentication UI, styled with SCSS
- Comprehensive testing stack including Vitest, Playwright, and Docker-based integration tests
- Production-grade Docker deployments with multi-stage builds and environment-driven configuration
- Infrastructure as code via Docker Compose, GitPod, and Render.yaml, with automated dependency updates
Code Quality
- Extensive test coverage across unit, integration, and end-to-end layers with robust mocking and test utilities
- Consistent error handling with custom error classes and standardized HTTP status codes across all layers
- Strong TypeScript enforcement with shared interfaces and schemas that span backend and frontend
- Modular design with domain-based package organization and dependency inversion patterns
- Unified linting, testing, and CI/CD pipelines with reusable test factories and component testing via real DOM simulation
What Makes It Unique
- Native integration of React Hook Form with Zod for type-safe, dynamic form validation in authentication flows
- Built-in Markdown documentation system that renders provider-specific guides directly in the UI
- Unified state machine for sign-in, MFA, and profile flows that enforces context-aware validation and transactional safety
- Automatic audit logging tied to tenant-aware routing, eliminating manual instrumentation
- Metadata-driven CAPTCHA and connector UI generation that reduces boilerplate for new identity providers
- Granular permission and MFA guards embedded in route handlers, cleanly decoupling security from business logic