Add monitor-mode cron jobs: a cheap monitor source (monitor_script or
monitor_url) runs on every tick BEFORE any agent machinery is built.
Its output is hashed as exact bytes and compared to the hash stored
from the last agent-triggering tick:
- unchanged -> agent run suppressed entirely (no LLM, no delivery);
the tick is recorded as a silent no_change run visible in the
executions ledger doc
- changed -> a MONITOR CHANGE DETECTED block (capped unified diff of
previous vs current output + the new output) is injected into the
prompt via the existing extra_prompt seam, then a normal agent run
- first run -> always runs the agent with a baseline block
- source failure -> delivered as an ERROR alert, never treated as a
change; the stored hash is untouched so recovery to prior output
still suppresses
Implementation:
- cron/monitor.py (new): hash/diff/URL-fetch/state persistence.
monitor_script reuses _run_job_script (same ~/.hermes/scripts/
containment + interpreter rules); monitor_url is a bounded GET
(30s, 256KB, http/https only). Output is exact bytes by design —
scripts should emit stable output (documented).
- cron/jobs.py: additive job fields monitor_script / monitor_url /
monitor_state {last_output_hash, last_changed_at}. JSON job records
need no migration. create-time validation: sources are mutually
exclusive and incompatible with no_agent=True.
- cron/scheduler.py: one tight monitor gate in run_job between the
no_agent short-circuit and the LLM path (outside sibling-lane
regions). State persists in jobs.json + a per-job snapshot file, so
suppression survives scheduler restarts.
- tools/cronjob_tools.py: additive optional monitor_script/monitor_url
params on the cronjob tool (create + update, empty string clears),
path containment validated at the API boundary, surfaced in
_format_job.
- hermes_cli: --monitor-script/--monitor-url on `hermes cron create`
and `hermes cron edit`; `hermes cron list` shows the monitor source
and last-changed time.
Tests (tests/cron/test_monitor_kind.py, TDD): unchanged suppresses,
changed injects diff, first run always runs, hash persists across
module reload (restart), script failure is error-not-change with hash
untouched, create/update validation, tool wiring + path-escape reject.
Inspired by: ChatGPT Work monitor tasks (idea-level, docs-only);
enabler: #80774