Cost Tracking
Track API token costs for specific operations in Claude Code. Use when the user invokes /cost-tracking to start measuring costs, or says "stop tracking", "stop cost tracking", or "how much did that cost" to stop and calculate. Tracks input, output, and cache tokens per API call and calculates USD cost using current Anthropic pricing.
Install
$ agentstack add skill-jbdamask-john-claude-skills-cost-tracking ✓ scanned · ✓ verified, works with Claude Code, Cursor, and more.
Security review
✓ PassedNo issues found. Passed automated security review. · v0.1.0 How review works →
- ✓ Prompt-injection patterns
- ✓ Secret / credential exfiltration
- ✓ Dangerous shell & filesystem operations
- ✓ Untrusted network calls
- ✓ Known-malicious package signatures
What it can access
- ✓ Network access No
- ✓ Filesystem access No
- ✓ Shell / process execution No
- ✓ Environment & secrets No
- ✓ Dynamic code execution No
From automated source analysis of v0.1.0. “Used” means the capability is present in the source — more access means more to trust, not that it’s unsafe.
Verified badge
Passed review? Show it. Paste this badge into your README, it links to the public security report.
Links to your public security report.[](https://agentstack.voostack.com/security/report/skill-jbdamask-john-claude-skills-cost-tracking) Reliability & compatibility
Declared compatibility
Compatibility is declared by the source manifest. End-to-end runtime verification is coming, see below.
We're building live execution health for every listing: tool-call success rate, median latency, uptime, and last-checked timestamps, measured, not self-reported. It isn't live yet, so we don't show numbers we can't stand behind.
How agent discovery & health will work →About
Cost Tracking
Track the exact token cost of any Claude Code operation by marking a start and stop point in the session JSONL.
Start Tracking
When the user invokes /cost-tracking:
- Determine the current session JSONL path. It lives at:
`` ~/.claude/projects//.jsonl ` Find the project directory by looking for the most recently modified .jsonl file under ~/.claude/projects/. The project hash is a mangled version of the working directory path (slashes replaced with dashes, e.g., -Users-johndamask-myproject`).
- Determine the cost tracking output directory:
`` ~/.claude/projects//cost-tracking/ ``
- Run the start script:
``bash python3 /scripts/start_tracking.py ``
- Store the returned
tracking_id— mention it to the user and remember it for the stop step.
- Confirm: "Cost tracking started. I'll calculate costs when you say 'stop tracking'."
Stop Tracking
When the user says "stop tracking", "stop cost tracking", or asks about the cost:
- Run the stop script with the tracking_id from the start step:
``bash python3 /scripts/stop_tracking.py ``
- The script outputs a formatted cost report and writes:
tokens.jsonl— per-entry token log with timestamp, model, inputtokens, outputtokenssummary.json— aggregated cost breakdown by model
- Present the report to the user.
Pricing
Pricing is stored in resources/pricing.json (last updated 2026-03-08, source: https://platform.claude.com/docs/en/about-claude/pricing). The stop script loads this file at runtime. It distinguishes between 5-minute and 1-hour cache writes using the cache_creation.ephemeral_* fields in the session JSONL. If pricing appears stale, fetch the pricing page and update resources/pricing.json.
Source & license
This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.
- Author: jbdamask
- Source: jbdamask/john-claude-skills
- License: MIT
Install and usage instructions live in the source repository linked above.
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Versions
- v0.1.0 Imported from the upstream source.