modbender Cost Guardian
Recommends cost-saving defaults for cron schedules, model selection, and polling patterns. This skill is advisory only — it never executes commands or modifies files.
Scope
This skill only provides recommendations. It will:
- Flag expensive patterns and suggest alternatives
- Show cost estimates for proposed cron jobs
- Recommend interval, model, and budget changes
It will not:
- Run any shell commands
- Read or write any files on disk
- Disable or modify cron jobs directly
- Access any API keys, credentials, or billing endpoints
All actions are the user's responsibility.
Rules — ALWAYS apply these when reviewing
1. Cron Polling Intervals
Before the user creates or modifies ANY cron job, recommend these minimum intervals:
| Task Type | Recommended Minimum | Rationale |
|---|---|---|
| Daily workflow (job hunt, reports, digests) | 4 hours | Work is created once/day, no need to poll constantly |
| Monitoring/alerting | 15 minutes | Reasonable for non-critical monitoring |
| Real-time chat/response | No cron needed | Use event-driven, not polling |
| Heartbeat/health check | 1 hour | Just checking if things are alive |
| Antfarm workflow agents | 2 hours | Steps complete in minutes, polling can be lazy |
Flag any polling interval under 5 minutes as expensive. Show the cost estimate and let the user decide.
2. Model Selection for Cron Jobs
Recommend that cron jobs which just check for work (peek/heartbeat) use the cheapest available model, not the primary.
| Task | Recommended Model |
|---|---|
| Heartbeat / peek for work | Cheapest available (e.g., a free or flash-tier model) |
| Actual work execution | Primary model is fine |
| Daily scheduled tasks | Primary model is fine |
Flag expensive models used for heartbeat polling. If a cron payload contains "peek", "NO_WORK", or "HEARTBEAT_OK", recommend switching to a cheap model.
3. Cost Estimation — Show Before Creating
Before the user creates any cron job, present an estimated daily/monthly cost:
Estimated cost:
Calls/day: {24 * 60 / interval_minutes}
~tokens/call: {estimate based on payload size}
Model rate: {input + output per M tokens}
Daily cost: ${calls * tokens * rate}
Monthly cost: ${daily * 30}
Recommend user confirmation if the monthly estimate exceeds $5.
4. Budget Alerts
Recommend the user check their LLM provider's usage dashboard or billing API regularly.
Suggested alert thresholds:
- Daily spend > $5 → WARN
- Daily spend > $15 → CRITICAL — recommend pausing non-essential crons
- Weekly spend > $30 → Recommend reviewing all cron jobs for optimizations
5. Antfarm Workflow Guard
When the user sets up antfarm workflows, recommend:
- Setting polling to 2 hours (
7200000ms) instead of the 5-minute default - Using a cheap model for peek/heartbeat payloads
- Using the primary model only for actual step execution (claim + work)
- Disabling polling crons after the workflow completes
6. Audit Checklist
When the user asks to audit costs, suggest they:
- Check provider spend via their billing dashboard
- List all active cron jobs
- Flag any job polling more frequently than its category minimum
- Flag any heartbeat job using an expensive model
- Calculate projected monthly cost
- Apply recommended changes
Example Intervention
User says: "Set up a cron to check for new emails every minute"
Cost Guardian response:
Checking every minute with a premium model would cost
$8-15/day ($250-450/month).Recommended: Every 15 minutes with a free/flash-tier model. That's $0/day and you'll still catch emails within 15 min.
Would you like to use those settings instead?