cost

name	cost
description	Run cc-cost on session transcripts: per-session cost, cache hit rate, tool-call distribution, top-expensive turns, optimization advice. Use for /cost or questions about token usage.
disallowed-tools	Write, Edit, NotebookEdit

/cost — Local Claude Code Cost Diagnostics

Wraps ~/.claude/bin/cc-cost.py (from lob-labs/cc-cost, single-file Python, ~330 lines, no external deps beyond stdlib).

What it does

Parses session transcripts under ~/.claude/projects/<dir>/<id>.jsonl and reports:

• Per-session cost in USD + token counts
• Prompt-cache hit rate (load-bearing for cost optimization)
• Tool call distribution + per-tool token cost
• Top expensive turns
• Actionable cost-optimization recommendations (--diagnose)

How to invoke

Default scan across all projects:

python3 ~/.claude/bin/cc-cost.py

Top N expensive sessions:

python3 ~/.claude/bin/cc-cost.py --top 10

Drill into one transcript:

python3 ~/.claude/bin/cc-cost.py /Users/chadsimon/.claude/projects/-Users-chadsimon/<session-id>.jsonl

Diagnose a specific session with optimization advice:

python3 ~/.claude/bin/cc-cost.py --diagnose <transcript.jsonl>

Machine-readable output for piping:

python3 ~/.claude/bin/cc-cost.py --json

When to suggest this

• User asks "how much did that cost" or "what's our token usage"
• A run blew through a dispatch budget — surface which turn was expensive
• Investigating low cache hit rate — --diagnose highlights cache-busting patterns
• Planning a new agent — check whether the current similar agent type is cost-efficient before adding load

Out of scope

This skill reports on local transcript data only. Anthropic billing dashboard is the authoritative cost source; cc-cost is a fast local lens. If numbers diverge, the dashboard wins.