TermDefinition
AgentAn AI-powered application that acts on behalf of a user to access external services
Agent_IDA URI-based unique identifier for an agent (e.g., https://agent.example.com/.well-known/agent.json)
Agent AttestationA signed JWT proving the agent’s identity, verified against the agent’s published public key
App-side AuthorizationThe service (or gateway) approving an agent to access specific capabilities — Phase A of the trusted handshake
User-side AuthorizationThe end user consenting to an agent acting on their behalf via OAuth — Phase B of the trusted handshake
Trusted HandshakeThe core ATH principle requiring that both app-side and user-side authorization must be granted before access is allowed
Scope IntersectionThe effective permission set computed as the intersection of agent-approved, user-consented, and requested scopes
ATH GatewayA middleware that enforces the ATH trusted handshake and delegates OAuth flows to a service provider (Gateway Mode)
ATH ImplementorAny entity (gateway or service) that implements the ATH protocol
OAuth BridgeAn implementation-specific component that handles OAuth flows with service providers
ProviderA third-party service that an agent wants to access (e.g., email service, calendar, database)
Gateway ModeDeployment model where an ATH gateway sits between agents and services — service providers need zero changes
Native ModeDeployment model where services implement ATH endpoints directly
Discovery DocumentJSON metadata published at .well-known/ath.json (gateway) or .well-known/ath-app.json (service)