dvcrn Cost Governor - Subagent Cost Control
Pre-flight cost checks before spawning subagents. Tracks spend. Gates expensive operations. Prevents surprise $300+ bills.
Files Included
SKILL.md— This file (agent instructions)README.md— Human-readable setup guidecost-tracking-template.md— Copy this tonotes/cost-tracking.mdto get startedlib/cost-tracker.js— Core estimation and logging librarybin/cost-summary.js— CLI: daily/monthly spend summary
Problem Solved
You spawn a subagent for "research passive income ideas" on Opus. 30 minutes later: $12 gone. This skill estimates cost before execution, requires approval for expensive tasks (>$0.50), and tracks all spend.
When to Use
- Before spawning any subagent — estimate cost, log it
- Daily spend review — summarize costs vs budget
- Post-task reconciliation — compare estimated vs actual
Core Rules
- Every subagent spawn >$0.50 estimated requires explicit user approval
- All spawns get logged to
$WORKSPACE/notes/cost-tracking.md - Estimates use multipliers from historical data (see Cost Model)
- No silent expensive operations — always surface cost before execution
Cost Model
Based on historical data from cost-tracking.md:
| Task Type | Base Estimate | Multiplier | Effective Estimate |
|---|---|---|---|
| Creative (open-ended) | Token estimate | 7.5x | Apply to all creative tasks |
| Research (bounded) | Token estimate | 3x | Web search + synthesis |
| Technical (structured) | Token estimate | 2x | Code, config, structured output |
| Simple (template) | Token estimate | 1.5x | Fill-in, short responses |
Model cost rates (approximate per 1K tokens):
- Claude Opus: ~$0.075 input / $0.375 output
- Claude Sonnet: ~$0.003 input / $0.015 output
- GPT-4: ~$0.03 input / $0.06 output
- Grok 4.1 Fast Reasoning: ~$0.003 input / $0.015 output
- Claude Haiku 4.5: ~$0.0008 input / $0.004 output
Estimation Formula
estimated_cost = (estimated_output_tokens / 1000) * output_rate * task_multiplier
Example:
- Task: Creative writing (5000 tokens estimated on Opus)
- Calculation: (5000 / 1000) * $0.375 * 7.5 = $14.06
- Action: Require approval (>$0.50 threshold)
Setup
- Create cost tracking file:
mkdir -p ~/.openclaw/workspace/notes
touch ~/.openclaw/workspace/notes/cost-tracking.md
- Add header to
cost-tracking.md:
# Cost Tracking Log
| Date | Task | Model | Est. | Actual | Ratio | Notes |
|------|------|-------|------|--------|-------|-------|
- Set your daily budget (optional):
echo "DAILY_BUDGET=20.00" >> ~/.openclaw/workspace/.env
Usage
Pre-Flight Check (Before Spawning)
User: "Research passive income methods"
Agent: Checking cost... Estimated $3.50 (Research task, Opus, ~3K tokens * 3x multiplier). Approve?
User: Yes
Agent: [spawns, logs to cost-tracking.md]
Daily Spend Dashboard
Run manually or via cron:
## Daily Spend — 2026-02-21
| Task | Model | Est. | Actual | Ratio |
|------|-------|------|--------|-------|
| PassiveIncomeResearch | Opus | $3.50 | $4.20 | 1.2x |
| AIHardwareResearch | Sonnet | $0.80 | $0.65 | 0.8x |
**Total:** $4.30 est / $4.85 actual
**Budget remaining:** $15.15 / $20.00 daily
Post-Task Reconciliation
After each subagent completes:
- Check actual cost (if available via
/status) - Log to
cost-tracking.md - Update multipliers if ratio is consistently off
Triggers
- Pre-spawn gate: Before
sessions_spawn, estimate and log. If >$0.50, ask user. - Cron (daily, optional): Summarize daily spend, flag overruns.
- Post-task: Log actual cost, update multipliers if data available.
Approval Gate Flow
- Estimate cost using model + task type + multiplier
- If estimate ≤ $0.50 → proceed, log silently
- If estimate > $0.50 → present estimate to user, wait for "approve" / "yes"
- Log decision (approved/rejected/modified) to tracking file
Budget Alerts
Set a daily budget cap. When spend exceeds it, the agent stops spawning and notifies you.
Setup: Add to your workspace config or mention it in system prompt:
"Daily API budget: $XX. Stop spawning subagents if estimated total exceeds this."
Cron-based daily summary (optional): Add to your cron:
# Daily cost summary at 11 PM
0 23 * * * node ~/.openclaw/workspace/skills/cost-governor/bin/cost-summary.js --daily
Anti-Patterns (What NOT to Do)
- ❌ Spawning Opus for simple lookups (use Sonnet or Haiku)
- ❌ Open-ended creative tasks without cost ceiling ("write a novel")
- ❌ Multiple subagents when one suffices
- ❌ Skipping post-task reconciliation
- ❌ Ignoring consistent ratio mismatches (update multipliers!)
Advanced: Custom Multipliers
Edit multipliers in your cost-tracking.md header:
## Multipliers (Updated 2026-02-21)
- Creative: 10x (our tasks run long)
- Research: 2.5x (bounded queries)
Agent reads these on each check.
Integration with Other Skills
- sessions_spawn: Always run cost check before spawning
- AGENTS.md: Log cost in agent entry ("Last used: $X.XX")
- Cron jobs: Wrap expensive recurring tasks with cost gates
Troubleshooting
Q: Estimates are consistently off A: Update multipliers in cost-tracking.md based on actual ratios.
Q: How do I get actual costs?
A: Use /status after subagent completes, or check provider dashboard.
Why This Matters
Real story from r/LocalLLM (Jan 2026):
"Left my OpenClaw agent running overnight. Spawned 8 research subagents on Opus. Woke up to $340 API bill. This skill would've saved me."
Don't be that person.
Author: OpenClaw Community
License: MIT
Requires: OpenClaw with subagent support, notes/ directory