The enforcement half of the lease broker ships and denies; the promotion half
has no production caller anywhere in the package. Verified across 0.0.48, 0.0.49
and 0.0.50-next.2207: begin_verification / observe_receipt / promote_lease are
invoked only by broker-test-client.ts, the acceptance spec, unit tests, and two
probes under docs/.
Consequence: no lease on any host can reach VERIFIED, so mutator-gate denies
every mutator with MUTATOR_UNVERIFIED via a gate that nothing shipped can
satisfy. Runtimes that enforce the gate in-process (pi, via mosaic-extension's
tool_call hook) are bricked for mutators; runtimes whose gate is wired through a
settings hook escape only when that hook is absent — i.e. by being ungated.
This adds the client. It implements protocol steps 1, 4 and 5:
1. begin_verification -> mint a challenge, return the exact receipt text
2. the MODEL emits that text verbatim as its entire latest message
3. the runtime adapter ships that message to the observer socket
4. observe_receipt -> PENDING_PROMOTION
5. promote_lease -> VERIFIED
Step 2 is deliberately NOT implemented here, and that is the point.
is_verbatim_receipt uses hmac.compare_digest against the exact minted string —
explicitly "not a transcript substring" — which makes promotion a LIVENESS
PROOF: it requires a live model that received the challenge in its context and
echoed it exactly.
receipt-observer-client.py will post ANY string as the latest assistant message.
A promotion client that posted its own receipt would satisfy the broker while
proving nothing — a gate-disabler indistinguishable from a working fix unless
someone specifically looks. Emitting the receipt therefore belongs to the runtime
adapter, where a real model turn happens. A local diagnostic that posts its own
receipt exists in the operator's repo and is deliberately NOT shipped here.
The construction binds the exact normative source bytes, so a VERIFIED lease
means "this agent is running THIS law", not merely "this session id is known".
h_source/h_payload are derived by importing the framework's own
normative_fragments.build_payload rather than reimplementing it: the broker
derives them the same way and any divergence yields PAYLOAD_BINDING_MISMATCH.
There must be exactly one implementation.
session_identity() prefers the generation FILE over the env var, matching
lease_generation.py. Sending a generation higher than the broker's would revoke
the session's own authority (daemon.py:342-344), so it never guesses.
Verified end-to-end on sb-it-1-dt under a real lease-gated anchor: a mutator
denied rc=2 MUTATOR_UNVERIFIED, then begin -> observe -> promote -> VERIFIED,
then the same mutator allowed rc=0. Negative controls pass: a fresh session is
still denied, and an unrelated session still reads UNVERIFIED — promotion is
per-session and does not leak.
Still open: adapter wiring for step 2. Lazy promotion on first mutator attempt
avoids colliding with the Constitution's first-response mode declaration, since
compare_digest requires the receipt to be the WHOLE message.
Jason Woltje
7272cfdc88