agentburn

Where did my Claude Code money go? It reads the session transcripts already sitting in ~/.claude/projects/, prices every model turn at Anthropic list rates, and breaks your burn down by project, model, day, and session — plus a cache-hit ratio that usually explains the biggest number on the page.

$ agentburn

  agentburn — ~/.claude/projects
  4 sessions · 122 model turns · $40.53 at list price
  11.52M in · 0.50M out · cache hit 62%

  project            turns  cost     cache%  tokens
  ──────────────────────────────────────────────────────────────
  gameforge          34     $29.04   63%     2.59M in · 0.12M out
  FictionFlow        28     $6.40    61%     2.92M in · 0.11M out
  tokenzip           41     $3.21    62%     5.27M in · 0.24M out
  pustakita          19     $1.87    58%     0.74M in · 0.04M out

(Sample output from fabricated transcripts — node gen-demo.mjs regenerates it. On a real machine it reads your real history.)

Why the two numbers that matter are turns and cache%

Claude Code re-sends context every turn. A 40-turn session that writes a big project to cache on turn 1 and reuses it 39 times is cheap. The same session blowing its cache every few turns (/compact, switched model, changed MCP servers) pays full input price repeatedly — that's the bill you never see explained anywhere else. agentburn surfaces it per project:

• turns — how chatty the session really was
• cache% — share of input served from cache (90% cheaper than fresh)
• cost by model — the opus rows always sort first, and they should

Usage

npx @asynx6/agentburn   # or npm i -g @asynx6/agentburn
agentburn                    # totals + top projects
agentburn --models           # which model ate the budget
agentburn --days             # per-day table (find your bad Tuesday)
agentburn --sessions         # top individual sessions
agentburn --project tokenzip # one project, all details
agentburn --since 2026-09-01 # cutoff
agentburn --dir ./transcripts   # custom path (CI, other machines)
agentburn --json             # machine-readable, pipe to anything

Zero dependencies, Node ≥ 18, single file, auditable. Reads local JSONL only — nothing is uploaded anywhere, no API key needed.

Honest limitations

• Prices are Anthropic list numbers from lib/pricing.js (2026-09). Max/enterprise plans, prompt-discount agreements, or third-party backends (Bedrock/Vertex contracts) bill differently. Unknown models are counted as $0 and listed, never guessed.
• Transcript usage is what the API reported — it excludes any overhead your plan adds.
• Sub-agent (sidechain) turns are counted, attributed to their parent project; they show up as high turn counts.
• Claude Code can rewrite transcripts (compaction); we dedupe by message uuid but a rewritten history is billed as-is.
• The number is a ceiling estimate "what this would cost at list price", not a invoice reconciliation.

Tests

node test.js   # pricing math, dedupe, project parsing, --since

Ecosystem

Made by the same hands as tokenzip (what one image costs before you send it) and vibe-locker (what you leaked while shipping). agentburn closes the loop: tokenzip saves the tokens up front, agentburn shows what happened after.

License

MIT