Monitor Law Gate

Skill: Monitor-Law Gate (gen-18 Track 1 #2)

Fleet law: canon #7 owns claim/guard/DONE/harvest-close. This skill is the deterministic monitor/collab enforcement gate.

Scope

Asserts the monitor is persistent, armed on the ACTIVE collab channel, and carrying a heartbeat marker.

What It Is

A deterministic detector over a lead/orchestrator transcript: when there is in-flight work (spawned workers) and an active collab channel, it asserts a persistent monitor is armed ON the active channel and keyed to a real heartbeat marker (### / ORC-RECEIPT: / @name / BLOCKED). The pinned RED/GREEN fixtures ARE the replayable gate (R-003/R-014 pattern).

The detector must not accept a prose claim like monitor=X as proof. When heartbeat or registry ground truth is available, the claimed monitor id is checked against it: stale heartbeat, missing id, or a live heartbeat on the wrong collab file is a FLAG. Same-turn Monitor/tail -f evidence still proves the monitor shape; registry/heartbeat evidence proves liveness.

Registry-Polling Doctrine (2026-07-02)

After three same-day monitor-death cascades (model flips and app restarts left registry agents inbox_monitor_not_alive while completed workers sat unharvested), worker-completion watching must be registry-polling, not session-tail based.

• Completion detection polls durable ground truth: list_agents state=done and/or registry state files.
• Session-scoped inbox heartbeats and tail monitors are not completion detectors; they die with model flips and app restarts, leaving the lead idle-and-blind while believing it is armed.
• Persistent collab monitors remain required for inbound coordination on the active channel. They catch new posts, blockers, and receipts, but they do not replace registry polling for worker completion.
• A lane that is stood down with disclosure and acknowledgement, with no active sprint and no live workers remaining in the registry, is allowed to have monitor=none.

Violation Taxonomy

GREEN: a persistent Monitor (or tail -f … | grep backstop) on the active channel keyed to ^### |ORC-RECEIPT:|@<name>|BLOCKED with live heartbeat/registry proof when a monitor id is claimed; or no in-flight lead/orc work (N/A). Worker seats, monitor-policy discussion, and disclosed/acked stand-down states are false-positive guards.

How /orc Consumes It

This backs /orc's SECOND CARDINAL RULE ("arm an inbound monitor first"). Before a lead/orc ends its first sprint turn — after spawning any worker — run the gate on the turn. A FLAG means: arm a persistent monitor on the ACTIVE channel keyed to the heartbeat marker BEFORE going quiet. The orchestrator may pass { activeChannel: "<path>" } when it knows the channel authoritatively.

bun test skills/golem-powers/monitor-law-gate/evals/monitor-law-gate.test.mjs
python3 skills/golem-powers/monitor-law-gate/evals/run_suite.py
bun skills/golem-powers/monitor-law-gate/scripts/monitor-law-gate-cli.mjs <transcript.jsonl|->   # exit 3 = FLAG

Programmatic: import { detectMonitorLaw } from "./src/monitor-law-gate.mjs" → { verdict, violations, activeChannel, monitors, inFlight }.

Hook wiring uses scripts/monitor-law-gate-hook.mjs as a Claude Code Stop hook. The hook is local-only: bounded stdin/path reads, no subprocesses, no network, no BrainLayer, fail-open on malformed input or internal errors. Stdout schema is exactly {} to allow, {"decision":"block","reason":"..."} to block, or {"systemMessage":"..."} for advisory fail-open conditions. Install with the checked-in install-snippet.json; it pins the absolute Node path because the fleet-wide bare node shim is not trusted for hooks.

Stated Limits

Marker-anchored over the turn's tool calls; the active channel is inferred from the collab path the agent posts to / dispatches about unless the caller forces opts.activeChannel. New evasion shapes are pinned as RED fixtures (R-003 model).