
Guardian turns "human approves" into a verifiable, scoped, time-bound, revocable cryptographic receipt that any action surface can enforce before allowing an action to proceed. The flow is simple: an agent that wants to take a consequential action requests a receipt; a human reviews the stated intent, parameters, and scope; on approval the Authority issues a signed JWS receipt with a 60-second TTL; the action surface verifies the receipt before executing — checking signature, expiry, revocation status, tool match, parameter binding, and scope conformance. Four demo-able protections: Per-action authorization — not session-wide delegation Parameter binding — a receipt for $10K cannot be used to execute $1M (the bait-and-switch defense, enforced via canonical sha256 of all action parameters) Live revocation — humans can halt an action mid-flight, not just block it before it starts Audit chain — receipts compose into a linked timeline via parent_rcpt references; receipts are the audit trail, no separate logging required
19 May 2026