Open-Source TypeScript Authentication Framework You Self-Host

Better Auth is an open-source, framework-agnostic authentication and authorization framework for TypeScript applications, created by Bereket Engida for developers who would rather own their auth layer than rent it from a hosted identity provider. The project raised a $5 million seed round led by Peak XV Partners in June 2025, took over maintenance of Auth.js (formerly NextAuth.js) that September, and announced in July 2026 that it was joining Vercel.

The library installs directly into an application rather than sitting behind an external API. Developers configure a server instance, pair it with a typed client SDK, and point it at their own database through an adapter that generates and migrates the required schema automatically. Core behavior covers email and password credentials, email verification, password reset, session and account management, and rate limiting, with everything beyond that added as a plugin.

Breadth is the main claim: more than fifty authentication methods, including passkeys, magic links, one-time codes, API keys and JWTs, roughly thirty-five social sign-on providers, and support across twenty-plus frameworks such as Next.js, Nuxt, SvelteKit, Astro and Hono. Organization plugins handle teams, roles and invitations for multi-tenant products, while enterprise deployments add SSO, SAML 2.0 and SCIM directory sync. A user-management dashboard and a Sentinel threat-detection layer cover session monitoring, audit logs and bot or IP blocking.