OpenClaw Face Cost Tracker

OpenClaw hook for tracking AI costs with delayed aggregation to avoid frequent calculations.

Features

• Delayed Calculation: Waits 1 minute after the last message before calculating costs
• Batch Processing: Multiple messages within 1 minute are batched together
• Session-based: Calculates costs per session from OpenClaw JSONL files
• R2 Storage: Uploads cost data to Cloudflare R2 for easy access
• Pre-calculated Costs: Uses OpenClaw's own cost calculations when available
• Fallback Calculation: Calculates from token usage when pre-calculated costs aren't available

Installation

1. Install dependencies:

pnpm install

2. Set up environment variables (create .env file):

R2_ACCESS_KEY_ID=your_access_key
R2_SECRET_ACCESS_KEY=your_secret_key
R2_ENDPOINT=https://your-account-id.r2.cloudflarestorage.com
R2_BUCKET=your-bucket-name

3. Test the hook:

pnpm test:push

How It Works

1. Message Received: When a message:received event occurs, the hook schedules a cost calculation for 1 minute later
2. Timer Reset: If another message is received within that minute, the timer resets
3. Cost Calculation: After 1 minute of inactivity, the hook:
   • Reads JSONL session files from ~/.openclaw/agents/main/sessions/
   • Parses usage data from the last 30 days
   • Calculates costs using model-specific pricing
   • Uploads results to R2 as cost.json

Cost Data Format

The cost data uploaded to R2 follows this schema:

{
  "timestamp": "2026-02-24T19:23:00.000Z",
  "sessionKey": "agent:main:main",
  "totalCost": 0.0159,
  "models": {
    "claude-sonnet-4-5": {
      "cost": 0.0159,
      "inputTokens": 100,
      "outputTokens": 500,
      "cacheReadTokens": 27000,
      "cacheWriteTokens": 0,
      "messageCount": 1
    }
  },
  "messageCount": 1,
  "lastMessageTime": "2026-02-24T19:22:45.000Z"
}

Model Pricing

The hook uses pricing from pricing.json in the hook directory.

To update pricing:

1. Edit pricing.json in the hook directory
2. Restart the hook to reload the pricing

The pricing file format:

{
  "claude-sonnet-4-5-20251101": {
    "input": 3.00,
    "output": 15.00,
    "cacheWrite": 3.75,
    "cacheRead": 0.30
  },
  "claude-opus-4-5-20251101": {
    "input": 15.00,
    "output": 75.00,
    "cacheWrite": 18.75,
    "cacheRead": 1.50
  }
}

Note: If a model is not found in the pricing file, its cost will be calculated as $0.

Integration with OpenClaw

This hook is designed to work with OpenClaw's hook system. Once installed, it will automatically:

1. Listen for message events
2. Schedule delayed cost calculations
3. Upload results to your R2 bucket

You can then build a dashboard (like the one in openclaw-face) to display the cost data from R2.

Development

• Test: pnpm test - Run unit tests
• Test Run: pnpm test:run - Run tests once
• Test Push: pnpm test:push - Test R2 upload functionality

License

MIT