AgentID: An Identity Protocol for Autonomous AI Agents

This document defines the AgentID Protocol, an open standard for establishing, verifying, and managing the identity of autonomous AI agents operating across the Internet. As AI agents increasingly interact with web services, APIs, and each other on behalf of humans and organisations, the industry lacks a universal mechanism to determine which agent is making a request, who is accountable for it, and what it is permitted to do. AgentID introduces the Agent Identity Token (AIT), a signed JWT carrying agent identity, owner verification, capability, and delegation chain claims. The protocol defines agent registration, owner verification levels, service-side access tiers, and transparent delegation chains with scope attenuation. It builds on existing standards including OAuth 2.0, OpenID Connect, JSON Web Token (JWT), and JSON Web Key (JWK), adapting them to the unique requirements of non-human autonomous actors.