claude-usage
Installation
SKILL.md
Claude Usage
Ground-truth token usage and cost reporting for Claude Code sessions. Parses JSONL files directly—parent sessions and subagent sidechains—to produce accurate numbers.
Why This Exists
ccusage (v18+, the standard community tool with 10.6k stars) undercounts output tokens by 77-94% for heavy users:
| Source | Output Tokens | Notes |
|---|---|---|
| Raw JSONL (all files) | 1,076,691 | Ground truth |
| Raw JSONL (date-filtered) | 412,987 | Properly filtered |
| ccusage --timezone UTC | 93,960 | 77% undercount |
| ccusage default | 62,375 | 94% undercount |
Three compounding bugs:
- Ignores subagent files at
{session-uuid}/subagents/{agent-id}.jsonl—132 files missed on a typical day with Agent Teams - Timezone confusion between UTC entry timestamps and local time filtering
- Drops entries in parent files—even at UTC, reports only 23% of actual tokens