Per the chosen design, the agent authorizes callers by comparing the request header X-Agent-Access-Token against its env AGENT_ACCESS_TOKEN (constant-time), no HM round-trip. AM contract §3.1 now states ① as the agreed integration with Python pseudo-code; the /agent-access/verify endpoint is demoted to an optional fallback. Client API §6 spells out the client's job: send X-Agent-Access-Token on every direct-connect request. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>