Vercel acquired Better Auth on July 7, 2026, bringing the open-source TypeScript authentication library and its core team into the company. Founder Bereket Engida and the team will build Agent Auth — a protocol that gives each AI agent its own scoped, revocable identity with the user as the single point of control.
Agent Auth assigns each agent a distinct identity rather than inheriting shared credentials or broad user-level permissions. An agent’s authority is limited to specific tasks, and the user can revoke it at any time. The design is meant to contain the blast radius when an agent acts outside its intended scope.
Better Auth comes with scale. The npm public API reports over 4.6 million weekly downloads, and the library has absorbed significant authentication infrastructure: it acquired Auth.js — formerly NextAuth.js — in September 2025 and closed a $5 million seed round led by Peak XV Partners in June 2025.
The MCP angle matters. Better Auth 1.5, released in February 2026, introduced MCP Auth — authentication built specifically for the Model Context Protocol that agents use to communicate with tools and services. Vercel’s product stack already includes the AI SDK, AI Gateway, Passport, and the eve agent runtime. Agent Auth plugs directly into this infrastructure as the identity layer.