Who is allowed to ask, and who is frozen.
Every agent id the guardrail has seen, with its status, how many decisions it asked for and when it was last seen. Freeze agent is the kill switch: the next request is refused before any check runs and the refusal is chained. Issue key binds the id to a key the agent must present, so nothing else can act in its name.
The way a bank freezes a card: nothing is evaluated, nothing moves, until Resume. Also an MCP tool, so an on-call engineer or a supervising agent can do it from anywhere.
A key is shown once; SafePay keeps only its sha256. A request with the key is that agent whatever its body claims; a keyed agent without it is refused. Unkeyed agents keep working, so the demo stays zero-setup.
On a locked host, freezing, issuing keys, applying policies and approving payments need the operator token. Paying never does: agents keep working either way.