cartoon 0.4.0

Token-optimized TOON output wrapper for any CLI

cartoon

Token-optimized output for any CLI. Prefix cartoon onto a command and its output becomes TOON — a compact structured format built for LLM agents. Same exit codes, same behavior, ~70%+ fewer tokens on test runs.

A cartoon is a compressed rendering of reality. So is this.

Why

Agents (Claude Code, Cursor, Codex, ...) read CLI output formatted for humans: banners, progress noise, hundreds of PASSED lines. You pay for every token. cartoon keeps what the agent needs — counts, failures, tracebacks — and drops the rest.

Install

uv tool install cartoon        # or: pipx install cartoon
npm install -g cartoon-wrap    # installs the `cartoon` binary
cargo install cartoon

For agents (Claude Code, Codex, Copilot, Cursor, …)

Teach your agent to use cartoon automatically — and to install it when missing — with the skills shipped in this repo:

# Claude Code (plugin)
/plugin marketplace add abhijitbansal/cartoon
/plugin install cartoon@cartoon

# Everything else (skills.sh CLI auto-detects 40+ agents)
npx skills add abhijitbansal/cartoon

Copy-paste blocks for AGENTS.md / copilot-instructions.md and the full integration matrix: docs/agents.md.

Auto-wrap hook (Claude Code)

The plugin ships a PreToolUse hook that rewrites noisy Bash commands to run under cartoon automatically — no skill recall needed. Standalone install (without the plugin):

cartoon hook install     # adds the hook to ~/.claude/settings.json
cartoon hook status      # check where it's active
cartoon hook uninstall   # remove it

What it wraps: dev-loop commands only — test runners, linters, typecheckers, builds (pytest, jest, vitest, tsc, eslint, ruff, mypy, make, cargo build|test|check|clippy, go test|build|vet, npm test|ci, …). Because a rewrite auto-approves the call, the allowlist is deliberately conservative: infra CLIs (docker, kubectl, terraform, gh, aws) and mutating subcommands (cargo publish, npm install) are never wrapped, commands that change shell state (cd, export, source) pass through untouched, and anything unrecognized is left alone (fail-open). The net-savings guard still applies — worst case the output is byte-identical.

Use

cartoon pytest                 # asymmetric test report in TOON
cartoon jest src/              # same for jest
cartoon vitest run             # same for vitest (watch mode passes through)
cartoon python -m unittest     # same for unittest
cartoon ruff check .           # lint diagnostics as a compact TOON table
cartoon npx eslint src/        # same for eslint
cartoon npx tsc --noEmit       # same for tsc type errors
cartoon aws ec2 describe-instances --output json   # any JSON CLI → TOON
cartoon make                   # safe tier auto-on: ANSI/progress/dupe collapse
cartoon --compress=aggressive make   # opt-in lossy: level filter, diag tables, windowing
cartoon -c 'cd app && make -j4'      # wrap a shell command string
cartoon ingest ci-run.log      # compress a log you already have
some-cmd | cartoon -           # same, from a pipe
cartoon --raw pytest           # escape hatch: no transformation
cartoon stats --since 7d       # how many tokens you've saved
cartoon learn                  # mine your own runs for config suggestions
cartoon adapters               # list built-in adapters
cartoon --tag api pytest       # tag the archived run
cartoon logs                   # list archived raw logs
cartoon logs --last --stdout   # full raw output of the newest run
cartoon logs grep ERROR --last # search a raw log instead of re-reading it
cartoon --fast pytest          # opt-in: parallel via pytest-xdist (-n auto)

Failing test run, before (pytest, ~4800 tokens) vs after (~300 tokens):

runner: pytest
summary:
  total: 48
  passed: 45
  failed: 2
  skipped: 1
  duration_s: 3.2
failures[2]{id,loc,msg}:
  "tests/test_auth.py::test_expiry","tests/test_auth.py:42",assert exp < now
  "tests/test_user.py::test_create","tests/test_user.py:88","KeyError: 'email'"
traces:
  "tests/test_auth.py::test_expiry"[2]: "tests/test_auth.py:42 in test_expiry",assert token.exp < now()

How it works

Every command (or ingested log) moves through one pipeline; the first stage that understands the content wins:

1. Adapter match — known runners (pytest, jest, vitest, …) get their machine-readable format injected and re-rendered as a compact report.
2. JSON detection — any JSON document in stdout is TOON-encoded.
3. Ladder, safe tier (default) — ANSI stripping, progress-bar collapse, duplicate-line collapse, blank-run collapse. Deterministic and non-lossy in practice.
4. Ladder, aggressive tier (opt-in) — log-level filtering (INFO/DEBUG to counts, WARN+ kept with context), near-duplicate templating, compiler-diagnostic extraction into a TOON table (gcc/clang one-liners and rustc multi-line blocks), error-anchored windowing.
5. Net-savings guard — the transform plus the raw_log footer must beat the original token count, or the original is emitted byte-identically. Trying cartoon is zero-risk by construction.

Every rule is a pure function that no-ops when its pattern is absent, so plain prose is never mangled. Measured on the golden corpus that runs in CI (token reduction at the aggressive tier, signal lines asserted intact):

Fixture	Reduction	Signal kept
chatty service log (156 lines, 1 ERROR)	−92.5%	ERROR + WARN verbatim, ±2 lines context
real cargo build failure (3 errors)	−61.5%	all errors + locations in a TOON table
npm ERESOLVE conflict	±0%	guard emits the original — never negative

Guarantees

• Exit codes always mirrored — cartoon pytest && deploy behaves like pytest && deploy.
• If parsing fails, the original output passes through untouched (one warning on stderr). The safe tier preserves all non-redundant text; lossy tiers are opt-in and always leave a raw_log pointer to the unmodified output.
• A transform must pay for itself: if the TOON rendering (footer included) wouldn't beat the original token count, the original is emitted byte-identically. Savings are never negative.

Raw log archive

Every wrapped run keeps its full raw output under ~/.local/state/cartoon/runs/<run-id>/ (stdout.log, stderr.log, meta.json). Transformed output ends with a raw_log: line pointing at the archive — if the TOON summary dropped something you need, search it with cartoon logs grep <pattern> --last (capped, disclosed) or fetch it with cartoon logs <id> instead of rerunning. Passthrough and --raw output stay byte-identical (no footer) but are still archived. Retention is capped (keep_runs, default 50; max_archive_mb, default 50); keep_runs = 0 disables archiving.

Fast mode

cartoon --fast pytest appends -n auto so pytest-xdist runs the suite in parallel. Strictly opt-in — parallel execution is NOT "same behavior" (test order changes; shared-state tests can flake), so cartoon never enables it on its own and always discloses it with a fast: "-n auto" line in the report. Failures under --fast? Rerun without it before debugging. If pytest-xdist isn't installed, cartoon retries serially once and notes it on stderr. Other runners: no-op (jest is already parallel; unittest has no parallel runner).

Config

~/.config/cartoon/config.toml:

tokenizer = "o200k"  # or "approx" (bytes/4) for zero-cost estimates
trace_lines = 20     # per-failure traceback cap
keep_runs = 50       # archived raw logs to keep (0 disables)
max_archive_mb = 50  # max total archive size

[compress]
level = "safe"       # default for non-adapter output: safe | aggressive

[command.docker]
level = "aggressive" # per-command pin; CLI --compress wins over config

Compression precedence: --compress flag > --heuristic (deprecated alias for aggressive) > [command.<name>] > [compress] > legacy heuristic key > safe.

Stats live in ~/.local/state/cartoon/stats.jsonl.

Adapters

Adapter	Trigger	Source
pytest	pytest, python -m pytest	injected --junit-xml
unittest	python -m unittest	stderr text parse
jest	jest, npx jest	injected --json
vitest	vitest run (watch mode passes through)	injected --reporter=json
swift-test	swift test	injected --xunit-output + --parallel (merges XCTest + Swift Testing files)
xcodebuild-test	xcodebuild test	injected -resultBundlePath, parsed via xcresulttool … test-results summary (Xcode 16+)
ruff	ruff check	injected --output-format json
eslint	eslint, npx eslint	injected --format json
tsc	tsc, npx tsc (not --watch)	injected --pretty false
swift-build	swift build	stdout/stderr text parse
xcodebuild-build	xcodebuild build (no test action)	stdout/stderr diagnostics parse

No adapter match → JSON auto-detection → compression ladder (safe tier by default, aggressive opt-in) → passthrough when nothing pays for itself.

Want another runner (cargo test, go test, rspec)? See CONTRIBUTING.md — adapters are one trait impl + fixtures. The roadmap lives in docs/superpowers/specs/2026-06-11-cartoon-v02-roadmap.md.

Support

If cartoon saves you tokens, a ⭐ on this repo helps other agent users find it — and cartoon stats will tell you exactly how much it earned one.

License

MIT