ccblame

git blame for your Claude Code spend — which subagent burned the budget?

ccblame reads your local ~/.claude transcripts and tells you which subagent, project, and workflow actually spent the money — not just a daily total. It runs entirely on your machine and never sends data anywhere.

npx ccblame

The problem

You kick off a workflow before lunch. It fans out subagents — a reviewer, a couple of researchers, a test-runner — and each of those spawns more. A /loop in one session, a scheduled task in another, a GitHub Action answering PRs. You come back and your weekly quota is halfway gone. Which one did that?

Here's what makes it expensive and invisible: every subagent starts with a cold cache. A cache write costs 1.25×–2× the base input rate; a cache read is ~0.1× (prompt-caching docs). A subagent doesn't inherit the parent's warm cache — it re-primes context from scratch, paying the cache-write premium on every spawn (a multi-turn agent recoups part of it via cheap reads on later turns, but the cold-start write repeats each time). Anthropic's own multi-agent research system used ~15× more tokens than chat. That cost is real, and no tool shows you who paid it.

Why the existing tools don't answer this

They give you plenty of totals — and almost no attribution.

| | Daily/session totals | Per-model split | Per-subagent $ | Spawn tree | Re-priming (cache writes) | |---|:---:|:---:|:---:|:---:|:---:| | Claude Code /cost | ✓ | ✓ | ✗ | ✗ | shows cache-write tokens, not as a spawn cost | | Claude Code /usage | ✓ | — | flat % by category | ✗ | ✗ | | statusline | ✓ | — | ✗ (can undercount subagents) | ✗ | ✗ | | ccusage | ✓ | ✓ | ✗ | ✗ | ✗ | | sniffly / cccost / ccost | ✓ | ✓ (some) | ✗ | ✗ | ✗ | | ccblame | ✓ | ✓ | ✓ | ✓ | ✓ |

/usage gets closest, but it's a flat category percentage — no dollars, no individual agent, no tree. ccusage nails daily/session/model totals and shows cache-write tokens as a column, but never asks which subagent they belonged to. And this isn't Anthropic's to fix soon: the feature request "Per-Subagent Token Usage Tracking" was closed as not planned ("there's no way to measure how many tokens each agent consumed"). ccblame is that missing view.

What you get

• Ranked table — every subagent invocation, costliest first. PRIME is the re-priming cost (cache-write tokens), READ is the cheap cache reuse, % is each agent's share of subagent spend.
• Headline — total split into main-thread vs. subagent spend, with the re-priming (cache-write) share called out: ▸ context re-priming (cache writes): $18.90 (54% of subagent spend).
• Spawn tree (--tree) — the parent→child hierarchy, each node carrying its own cost and its subtree's, so you see which branch is heavy, not just which leaf.
• Breakdowns (--by type | workflow | project | model | day) — the dimensions that answer "who?".
• Interactive drill-down (ccblame browse, needs fzf) — pivot through days, sessions, and agents live. No fzf? It falls back to the plain table.

Install

npx ccblame              # zero install — just run it
bunx ccblame             # same, via bun
npm install -g ccblame   # if you want it on PATH

Needs Node ≥ 18.3. Zero runtime dependencies — the whole thing is one bundled file.

Usage

ccblame                          # ranked subagent table + headline
ccblame --tree                   # spawn hierarchy with per-node cost
ccblame --by project             # group by project
ccblame --by workflow --top 10   # 10 costliest workflow runs
ccblame --project payer-policies # scope to one project (substring match)
ccblame --workflow wf_abc        # scope to one workflow run (prefix match)
ccblame --since 2026-06-01       # on/after a date (YYYY-MM-DD or RFC3339)
ccblame --until 2026-06-30       # on/before a date (pairs with --since)
ccblame --json                   # machine-readable, full dataset
ccblame browse                   # interactive drill-down (needs fzf)

Date boundaries for --since/--until and --by day are UTC. --top N trims the displayed table only — --json and every total stay full-population, so the numbers reconcile with your real spend.

The dollar figures are an estimate reconciled from your local logs (main-thread + subagent spend always sums to the grand total), not a copy of your billed Anthropic invoice. Unpriced or unknown models are flagged loudly (?) and counted as $0, so a total is always a floor — never a silent undercount.

How re-priming cost is computed

Each usage line records cache-write tokens in two TTL buckets — ephemeral 5-minute and 1-hour. ccblame sums those into PRIME (the write cost a spawn pays to load context) and keeps READ (cacheRead) separate. The headline prices those write tokens and reports them as a share of subagent spend — the number no other tool isolates: not "how many cache tokens," but "how much did re-priming subagents cost you."

It's an upper bound: a subagent that runs several turns reads part of that written cache back cheaply (caching breaks even after ~1–2 reads), so not every write dollar is lost. But the cold-start write repeats on every spawn — and that per-spawn re-priming is exactly the cost multi-agent workflows quietly rack up.

Privacy

ccblame reads token-accounting and routing metadata only — usage counts, model names, ids, timestamps, and agent labels. It never reads or emits the content of your messages, prompts, tool calls, or results. It reads ~/.claude (or $CLAUDE_CONFIG_DIR) locally and makes no network calls:

Reads ~/.claude (or $CLAUDE_CONFIG_DIR) locally. Never sends data anywhere.

JSON

--json emits the complete dataset for scripting:

{
  "total_cost_usd": 47.32,
  "main_thread_cost_usd": 12.05,
  "subagent_cost_usd": 35.27,
  "subagent_count": 38,
  "subagents": [
    {
      "agent_type": "code-reviewer",
      "description": "audit auth module",
      "model": "claude-opus-4-8",
      "project": "…",
      "depth": 1,
      "parent_agent_id": "…",
      "tokens": { "input": 4100, "output": 9800, "cache5m": 180000, "cache1h": 0, "cacheRead": 1200000 },
      "cost_usd": 1.99,
      "unpriced_model": false
    }
  ]
}

--by <dim> --json emits grouped output (by, total_cost_usd, groups[]) with the same reconciliation guarantees.

Development

bun test          # tests
bun run lint      # biome
bun run typecheck # tsc
bun run build     # tsdown → dist/cli.mjs

License

MIT