No-Agent Cron Job Pattern

Problem

LLM-driven cron jobs (even simple ones like "ping router and report") use an LLM on every tick — wasting tokens, adding latency, and most importantly causing the phantom typing indicator in Telegram. The user sees "agent is typing..." every few minutes even for trivial watchdog checks.

Solution: no_agent=true

When the cron job's task is a deterministic script check (ping, port test, service status, file check, API test), set no_agent=true. The script runs standalone — no LLM invoked, no typing indicator, zero tokens.

Design pattern

The script must:

Exit 0 (silent) when everything is fine — no output at all means no delivery
Print an error message and exit non-zero when something is wrong — stdout becomes the delivered alert
Need no LLM reasoning to compose the output

Implementation

cronjob action=update job_id=<id> no_agent=true prompt="" script=<script_name>

The prompt is ignored when no_agent=true. Only the script's stdout (on non-zero exit) is delivered.

Watchdog script template

#!/bin/bash
# watchdog.sh — Silent on success, alert on failure
# Runs via no_agent cron

TARGET="10.77.0.2"
SUCCESS=0

for i in 1 2 3; do
    if ping -c 1 -W 3 "$TARGET" >/dev/null 2>&1; then
        SUCCESS=$((SUCCESS + 1))
        [ "$SUCCESS" -ge 2 ] && exit 0  # silent
    fi
    sleep 5
done

echo "[-] $TARGET unreachable after 3 attempts"
exit 1

When NOT to use no_agent

The cron produces raw data that needs narrative synthesis (daily digest, tech briefing)
Multiple data sources need correlation before alerting
The output format must be platform-specific (e.g. HTML email)
A decision must be made from the data (e.g. "is this spike routine maintenance or a problem?")

Converting existing LLM-driven crons

Best candidates:

Watchdog/ping checks
Backup status checks
Bounce detection (scan inbox for bounces, output findings)
Security scans (Lynis, etc.)
Any cron where the output is "up/down" or "ok/fail"

2.0 KiB Raw Permalink Blame History