Resource Access
Resource Access Mode Comparison
AAuth defines five resource access modes, sorted by what the resource ends up knowing and which party established it — not by how much of the protocol they use. The protocol works in every mode, and adoption does not require coordination between parties. A resource MAY apply different modes to different endpoints. Agent governance (missions, permission, audit, interaction relay) is an orthogonal layer that any agent with a PS can add on top of any mode.
Agent identity
Agent + Resource
Resource knows
which agent
Established by
the agent provider
Tokens
Infrastructure
None — just the agent and resource
Best for
Replacing API keys with cryptographic identity
Resource-managed
Two-Party
Resource knows
which person
Established by
the resource's own flow
Tokens
Infrastructure
Resource handles auth itself (interaction, OAuth/OIDC, internal policy)
Best for
Resource manages authorization without an external PS or AS
Person identity
Three-Party
Resource knows
which person
Established by
the person server
Tokens
Infrastructure
Person Server only — never in the path of a call
Best for
Federated login for agents: the resource accepts a login the PS ran
PS authorization
Three-Party
Resource knows
person and consented scope
Established by
the person server
Tokens
Infrastructure
Person Server (no Access Server)
Best for
Resource accepts identity claims and consented scope from any PS
Federated authorization
Four-Party
Resource knows
person and policy verdict
Established by
the access server
Tokens
Infrastructure
Person Server + Access Server, PS-AS trust (pre-established or dynamic)
Best for
Cross-domain access with the resource's AS enforcing policy
Progressive Adoption
Each mode is independently deployable. A resource can start by just verifying the agent's signature (agent identity), later accept a login the PS ran (person identity), run its own flow instead (resource-managed), take consented scope from any PS (PS authorization), or deploy its own access server (federated) — without changing the agent's signing approach. What varies is what the resource challenges for and which party mints the eventual auth token. Resource-managed and person identity reach the same destination by different routes: in the first the resource runs its own login, in the second it accepts one the person server ran. A resource serving on identity alone challenges for auth-token only at the operations that need more, and keeps serving the rest on the person token.
Roles vs. deployment
AP, PS, AS, Resource, and Agent are roles, not deployment units. A single server can fill multiple roles — for example, an organizational deployment may operate AP + PS + AS together for employees and internal resources, with federation only incurred at the boundary. When the agent's PS and the resource's AS are the same server ("PS-AS Collapse"), federation reduces to a single internal evaluation. The wire protocol is unchanged regardless of collocation.