caliper-ai 0.0.45

Local cost ledger for AI-assisted development. Opens a private dashboard and per-PR cost reports from Codex, Claude Code, Cursor, and Aider logs.

Caliper

The local cost ledger for AI-assisted development.

Run one command. Get a private HTML dashboard showing what your AI coding actually cost — by project, PR, model, vendor, and session.

Offline by default. No account. No upload. No telemetry.

uv tool install caliper-ai
caliper dashboard

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Why it exists

AI coding tools are good at spending tokens and bad at explaining the bill. Vendor dashboards are per-tool, per-account, and behind logins. They don't know your local git history, your PRs, or which project caused the spend.

Caliper reads the logs already on your disk from Codex CLI, Claude Code, Cursor, and Aider, prices them with sourced rate cards, and answers questions those dashboards can't:

• What did this PR cost?
• Which project is driving the bill?
• How much did cache reuse save?
• Are these numbers exact, estimated, partial, or unsupported?

The answer never leaves your machine.

The first 30 seconds

caliper dashboard

Opens a self-contained HTML file in your browser. The verdict sits above the fold — period, cost, trend, and the top fix Caliper found:

Caliper · Last 14 days · $1,243 · trend +8.2% · top fix: Move low-output fast
                                                tier calls to standard ($96.40)
Fixable: $184.20 across 3 recommendations. Inspect with `caliper advise --strict`.
Theme: dark · local-only · re-render: caliper dashboard --open

Every KPI on the page has a "show the math" disclosure — the formula, the rate card date, and the sample size. Every insight carries a based on N events · M sessions · X tokens lineage chip. No claim without a citation.

How it's different

	Caliper	Hosted proxies (Helicone, Langfuse, …)
Where data lives	Local disk	Their servers
Sits on the request path	No	Yes — proxy or SDK
Login required	No	Yes
Reads existing AI-tool logs	Yes — Codex, Claude Code, Cursor, Aider	No — needs you to route through them
Per-PR / per-project cost	Yes — local git attribution	If you instrument it
Works with WiFi off	Yes	No

Caliper is the receipt from evidence already on your machine. If you need a request-path proxy, use one of those. If you want to know what last month actually cost — without sending prompts to a third party — use this.

What you get

Surface	Command	Purpose
Browser dashboard	caliper dashboard	Self-contained HTML report.
PR receipt	caliper pr 42	Cost attributed to one pull request.
Overview	caliper overview	Rolling 7 / 30 / 90 day spend.
Project rollup	caliper project	Spend by repository or folder.
Model rollup	caliper models	Spend by model and vendor.
Evidence report	caliper evidence	How trustworthy each dimension is.
Advisor	caliper advise --strict	Ranked, dollar-anchored fixes.
Doctor	caliper doctor	Local setup + data coverage.
Budgets	caliper budgets check	CI-friendly warning / breach exits.
TUI	caliper tui	Interactive terminal workspace.

PR receipt

caliper pr 42

Caliper · PR #42
128 events  432,118 tokens  $4.82   ·   7 commits

  Vendor        Model                 Events   Tokens (in/out)    Cached   $
  openai-codex  gpt-5.4 standard          74   210,000 /  31,000    61%   $2.10
  claude-code   claude-sonnet-4.6         31    88,000 /  12,000    48%   $1.12
  cursor        composer                  23    72,118 /  19,000    22%   $1.60

Missing git attribution is surfaced as partial evidence instead of being silently treated as exact.

Trust model

Boundary	Default
Login	none
Upload	none
Telemetry	none
Daemon	none
Request proxy	none
Network calls during usage analysis	none
Pricing refresh	explicit --allow-network
GitHub PR lookup	explicit --allow-network
Prompt output	redacted
Absolute paths	redacted in machine-readable output

The privacy invariant is enforced in CI. The generated HTML contains zero external resources, zero <script src>, zero fetch/XMLHttpRequest/import(). You can verify it on your own file:

grep -E "://|<script src|fetch\(|XMLHttpRequest|import\(" ~/caliper.html
# no matches

Accuracy

Caliper does not pretend every local log is perfect. It reports what the evidence supports.

• Costs use Decimal.
• Cached input, cache creation, output, and reasoning tokens are tracked separately when vendors expose them.
• Long-context multipliers are applied per model.
• Unknown pricing is surfaced as a warning, not silently guessed.
• Anomaly detection uses robust σ (MAD × 1.4826, IQR / 1.349) with a $1 absolute floor — no more "354,210σ" on a sparse Tuesday.
• Evidence is graded exact, estimated, partial, or unsupported. Each insight ships a sample-size chip. Each KPI exposes its formula inline.

caliper evidence
caliper doctor
caliper rates show

Budgets in CI

# .caliper.toml
[budgets]
daily_cost_usd = 25
weekly_cost_usd = 100
monthly_cost_usd = 500

caliper budgets check

Exit	Meaning
0	ok
1	warning threshold crossed
2	breach threshold crossed

Supported sources

Source	What Caliper reads
OpenAI Codex CLI	Local session logs, state DB, model + token fields.
Claude Code	Project JSONL logs, tool-use, cache token fields.
Cursor	Local token-bearing records where available.
Aider	Local chat history + usage records.

Files that are transcript-only or missing token counts are surfaced by caliper doctor so coverage stays explicit.

Install

Requires Python 3.11+.

# Recommended.
uv tool install caliper-ai
uv tool upgrade caliper-ai

The PyPI package is caliper-ai; the command is caliper.

Other install paths (pipx, venv + pip, uvx)

# pipx
pipx install caliper-ai
pipx upgrade caliper-ai

# venv + pip
python -m venv .venv && source .venv/bin/activate
python -m pip install caliper-ai

# uvx one-off (use --from to avoid name-collision resolution)
uvx --isolated --from caliper-ai caliper dashboard

If uv can't see a just-published version (stale PyPI index or resolver cache):

UV_NO_CACHE=1 uv tool install --force caliper-ai

FAQ

Does it work with Cursor today? Yes, when Cursor's local data includes token-bearing records. Some Cursor files are transcript-only. caliper doctor reports which.

How accurate are the costs? As accurate as your local logs and rate card allow. Run caliper evidence to see which dimensions are exact, estimated, partial, or unsupported.

Does Caliper upload prompts? No. Default usage analysis is local-only and redacts prompt-like fields from normal output. CI tests the privacy invariant on every commit.

Is there a hosted version? No. There is no hosted version on the roadmap. Caliper is intentionally a tool you run, not a service you log into.

Development

uv sync --all-extras --dev
uv run ruff check . && uv run ruff format --check .
uv run pytest

See CONTRIBUTING.md for rate-card updates, new vendor parsers, schema changes, and release hygiene.

Who built this

Rajdeep Mondal. I had a four-figure AI coding bill, a strong hunch about which work caused it, and no offline way to prove it. The first version paid for itself in one PR review.

License

MIT. See LICENSE.