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

### Implementation

```bash
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

```bash
#!/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"
