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:

1. Ignores subagent files at {session-uuid}/subagents/{agent-id}.jsonl—132 files missed on a typical day with Agent Teams
2. Timezone confusion between UTC entry timestamps and local time filtering
3. Drops entries in parent files—even at UTC, reports only 23% of actual tokens

This script reads every JSONL file to produce correct totals.

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Usage

# Today's usage (default)
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py

# Last 7 days, broken down by day
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --since 7d

# Weekly breakdown for the past month
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --by week --since 30d

# Per-model breakdown
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --by model --since 7d

# Per-session with human-readable summaries
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --by session --since 1d

# Per-project breakdown
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --by project --since 7d

# Filter to one project
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --project Thera --since 30d

# Custom date range
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --since 2026-02-01 --until 2026-02-28

# JSON output (pipe to jq)
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --since 7d --json | jq '.grand_total'

# CSV output
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --since 7d --csv

# Compare against ccusage (shows delta)
python3 ~/.claude/skills/claude-usage/scripts/claude_usage.py --compare

# PDF report (dark editorial, CTO-ready)
python3 ~/.claude/skills/claude-usage/scripts/claude_usage_report.py --since 30d

# PDF with custom output path
python3 ~/.claude/skills/claude-usage/scripts/claude_usage_report.py --since 30d -o ~/Desktop/feb-usage.pdf

# HTML only (no Playwright needed)
python3 ~/.claude/skills/claude-usage/scripts/claude_usage_report.py --since 7d --html

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Output Columns

Column	Description
Input	Prompt tokens (charged at input rate)
Output	Response tokens (most expensive category)
CacheW	Cache write tokens (cache_creation_input_tokens)
CacheR	Cache read tokens (significantly cheaper than input)
Total	Sum of all four token types
Cost	Estimated USD from the hardcoded pricing table

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Aggregation Modes (--by)

Mode	Groups by	Example key
day (default)	Calendar date in local timezone	2026-02-20
week	ISO week number	2026-W08
month	Month	2026-02
session	Session UUID (resolved to summary from sessions-index.json)	8a6c801a Working on Claudicle...
model	Model name	claude-opus-4-6
project	Project directory (decoded to path)	~/Desktop/Programming

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Pricing Table

Prices are hardcoded in the PRICING dict at the top of claude_usage.py. Update when Anthropic changes rates. Keys are model name substrings matched most-specific-first.

Current defaults (USD per million tokens, verified 2026-02-21):

Model	Input	Output	Cache Write (1h)	Cache Read
Opus 4.5 / 4.6	$5.00	$25.00	$10.00	$0.50
Opus 4.0 / 4.1	$15.00	$75.00	$30.00	$1.50
Sonnet 4.x	$3.00	$15.00	$6.00	$0.30
Haiku 4.5	$1.00	$5.00	$2.00	$0.10
Sonnet 3.7 / 3.5	$3.00	$15.00	$6.00	$0.30
Haiku 3.5	$0.80	$4.00	$1.60	$0.08
Opus 3	$15.00	$75.00	$30.00	$1.50
Haiku 3	$0.25	$1.25	$0.50	$0.03

Cache write column shows the 1-hour rate (2x base input). Claude Code uses 1-hour prompt caching exclusively. The 5-minute rate (1.25x base input) is also supported when the JSONL cache_creation sub-object provides a TTL split.

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Timezone Handling

JSONL timestamps are UTC. The script converts to the system's local timezone (or --tz America/New_York) before applying --since/--until filters. This prevents the midnight-boundary confusion that causes ccusage to drop entries when the UTC date differs from the local date.

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Data Sources

JSONL files at ~/.claude/projects/{encoded-path}/:

• Parent sessions: {session-uuid}.jsonl
• Subagent sidechains: {session-uuid}/subagents/{agent-id}.jsonl
• Session metadata: sessions-index.json (summaries for --by session)

The script uses streaming line-by-line reads (O(1) memory) to handle files exceeding 300MB.

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PDF Reports

claude_usage_report.py generates a dark editorial PDF with Crimson Pro + JetBrains Mono typography, gold Minoan accents, bar charts, model distribution with color-coded stacked bars, token composition breakdown, and detailed tables. Designed for executive sharing.

Requires Playwright (uv pip install --system playwright && playwright install chromium). Uses Chromium for pixel-perfect CSS rendering—same engine as the Aldea Slide Deck skill. Falls back to HTML output with --html flag.

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Caveats

• Estimated accuracy: ~95%. The remaining gap comes from data residency multipliers (1.1x for US-only inference, not tracked) and potential edge cases in streaming chunk boundaries.
• Streaming chunks are deduplicated by message ID using last-wins strategy—output_tokens monotonically increases across chunks, so only the final chunk per message ID has the correct value. Without dedup, costs were overcounted by 2-5x.
• Cost is estimated from the pricing table. Anthropic billing may differ due to batch discounts or promotional pricing.
• Cache write pricing uses the 1-hour rate by default (Claude Code's caching mode). When JSONL provides cache_creation.ephemeral_5m_input_tokens / ephemeral_1h_input_tokens, rates are split accordingly.
• Synthetic entries (model: "<synthetic>") and billing error entries (all-zero token counts) are automatically filtered.
• Malformed JSON lines and duplicate streaming chunks are counted and reported in the output footer.
• Requires Python 3.9+ for zoneinfo module.
• PDF reports require Playwright with Chromium (playwright install chromium). Includes a Pricing Methodology section with full rate table, formula, and confidence badge.