Logto

Logto is open-source authentication and authorization infrastructure for SaaS and AI apps. It helps teams build production auth without handling OIDC and OAuth 2.1 details from scratch, while adding multi-tenancy, enterprise SSO, and RBAC for customer-facing products.

It supports pre-built sign-in flows, customizable UIs, and SDKs for 30+ frameworks. It also covers SAML, social login, MFA, Google One Tap, and integrations for SPAs, web apps, mobile apps, APIs, M2M, and CLI tools. It is ready for Model Context Protocol and agent-based AI architectures.

Logto offers a cloud service and an OSS path for local development through Docker Compose or Node.js with PostgreSQL. It is licensed under MPL-2.0, and the self-hosted setup is described as OSS installation rather than a managed-only service.