Interoperability

Agent Policy is intentionally engine-neutral. It can wrap outputs from a rule engine, authorization service, access-control gateway, identity-aware proxy, local settings resolver, or human review flow.

Alignment map

System	Alignment
OPA	Can evaluate arbitrary structured input and return structured decisions; Agent Policy can normalize the result for agent systems.
Cedar	PARC-style authorization maps naturally to subject/action/resource/context.
XACML	PDP/PEP separation and decision vocabulary inform fail-closed enforcement.
OAuth/OIDC	Tokens and scopes can be inputs or refs, but Agent Policy does not mint or validate tokens.
MCP	Tool/resource/prompt calls can be policy actions; Agent Policy can describe approval and grant semantics around them.
A2A	Peer-agent tasks and artifacts can carry policy refs during delegation and handoff.
CloudEvents	Policy events can be transported in a common event envelope.
OpenTelemetry	Policy decisions can correlate with traces, spans, and GenAI semantic events.
Agent Evidence	Evidence packs can include policy decisions, approvals, grants, waivers, and traces.

Boundary rule

If the question is "how do I write rules?", use a policy engine. If the question is "who is authenticated?", use identity and authorization infrastructure. If the question is "what did the agent policy decide and how should adjacent systems exchange that fact?", use Agent Policy.