crapkit
Twelve tools to inspect CRAP scores, find work, and check edited functions against their ceiling.
Open source Open in the app JSON README (API)
About
Twelve tools to inspect CRAP scores, find work, and check edited functions against their ceiling.
Details
- Kind
- MCP servers
- Topic
- No topic detected
- Publisher
- jeanfrancoisgagne
- Origin
- official
- Category
- ferramentas
- Transport
- local
- Version
- 0.7.0
- Stars
- 1
- Forks
- 1
- Open pull requests
- 1
- Last push
- 2026-09-06T22:31:34Z
- Repository state
- ativo
- Language
- Python
- License
- MIT
- Added
- 2026-09-05 11:00:26
- Updated
- 2026-09-08 01:01:06
- Origin id
io.github.JeanFrancoisGagne/crapkit
README
# crapkit
<!-- mcp-name: io.github.JeanFrancoisGagne/crapkit -->
[](https://github.com/JeanFrancoisGagne/crapkit/actions/workflows/ci.yml)
[](https://pypi.org/project/crapkit/)
[](https://pypi.org/project/crapkit/)
[](https://github.com/JeanFrancoisGagne/crapkit/blob/main/LICENSE)
[](https://glama.ai/mcp/servers/JeanFrancoisGagne/crapkit)
crapkit scores every function in your repo on complexity times uncovered risk, ranks the
worst ones by how often the file changes, and blocks commits that add more. It reads
Python, TypeScript, TSX, JavaScript, Swift, Go, Rust, shell, PowerShell, C and C++,
Objective-C, Vue, Java and Zig through [lizard](https://github.com/terryyin/lizard), and
joins per-function branch coverage from the istanbul or coverage.py artifact your own test
command already writes. Every read command speaks sorted-keys JSON on a pinned schema,
because half the callers are coding agents.
```
CRAP = ccn^2 * (1 - cov)^3 + ccn
```
The name is not ours: C.R.A.P. (Change Risk Anti-Patterns) was coined for crap4j by
Alberto Savoia and Bob Evans in 2007.
`ccn` is the smaller of standard and modified cyclomatic complexity, both read off one
lizard pass. `cov` is branch coverage inside the function's span; with no branches it
falls back to statement coverage, and with no statements to invoked-or-not, so a
half-executed straight-line function never reads as fully covered.
**Above the ceiling, coverage cannot save you. Decompose.** At the default target of 6, a
function at ccn 7 with 100% coverage still scores 7 and still fails the gate. The only
move that clears it is splitting the function.
**Why 6 and not 30.** crap4j's conventional threshold of 30 is a CRAP score: it lets an
untested `ccn 5` through (25 + 5 = 30) and a fully covered `ccn 30` too. crapkit's default
is a complexity ceiling, because coverage can at best collapse CRAP to `ccn`, and a
function you cannot cover past `ccn 6` is one you decompose. Set `target = 30` in
`crapkit.toml` if you want the crap4j number. A repo with existing debt does not need to:
`ratchet seed` marks today's over-ceiling functions at today's score, the gate then judges
only the functions a change touches, and marks may only fall, so adoption never starts with
a wall of red. Next to crap4py, radon, xenon, wily and SonarQube:
[docs/comparison.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/comparison.md).
crapkit scores **git-tracked files only**. Source you have not `git add`ed is invisible to
it.
---
## The 60-second start
```
pip install crapkit
cd your-repo
crapkit init # crapkit.toml and .gitignore lines, plus a live coverage lane when it
# recognizes the runner and a scope speaks its language: pyproject.toml,
# pytest.ini or setup.cfg for pytest; a test script or vitest/jest in
# package.json for the JS side
# without one: the lane comes commented out, init says to declare one,
# and docs/lanes.md is how to fill it in
crapkit coverage # runs the lane, joins coverage, stores a scored run
crapkit worklist # the ranked risk map
crapkit ratchet seed && git add crapkit.toml crapkit-ratchet.tsv .gitignore
```
`coverage` scores, `worklist` ranks:
```
$ crapkit coverage
run 1 @ fae4db93108: 2 functions scored: 2 measured, 1 over ceiling 6, CRAP load 41.0, grade F
-> next: crapkit worklist
$ crapkit worklist
worklist @ fae4db93108 (run 1, floor ccn>=5, churn 12mo) - 1 of 1 active (worklist_top 50), 0 dormant
risk 14.0 ccn 14 crap 38.5 cov 50% 1c/1a calc/grade.py:7 classify( score , attempts , late , bonus )
```
`risk 14.0` is ccn times a churn weight of one: a one-commit repo has no spread of commits
to weight, so each commit counts once and the ranking is complexity order until the
history grows ([Risk](#risk-what-ranks-the-worklist)). `crap 38.5` and `cov 50%` are the
score and the coverage behind it.
`ratchet seed` signs today's debt at today's score. From then on marks only ever fall, so
the repo can get better and never worse while you burn it down.
**One thing stops most first runs: the coverage plugin.** `init` writes a lane that shells
out to your own test runner, and the runner needs its coverage package installed:
`pytest-cov` for pytest, `@vitest/coverage-v8` (pinned to your vitest major) for vitest.
Without it the lane produces no artifact and `coverage` exits 5 quoting the runner's own
error. For pytest, `init` probes the python its lane will run and prints the install
command when `pytest_cov` is missing; `pip install "crapkit[py]"` pulls the plugin
alongside crapkit when the two share a venv. On a Windows PATH holding only the `py`
launcher it writes `py`, not a `python3` the lane could never run, and when cmd.exe cannot
start the interpreter at all (exit 9009, the Store alias) it names that instead of guessing
at pytest-cov. A repo that pins no lockfile and carries its own `.venv` gets that venv's
interpreter in the lane, when that interpreter can import pytest, rather than whichever
python the shell answers with. The two quickstarts below walk a real repo end to end.
**On Windows a lane command is read by cmd.exe**, the shell that will run it, not by sh.
Double quotes are the portable quoting. A single-quoted value is refused at config load
with exit 3, because cmd.exe would hand pytest five words and the lane would write no
artifact:
```
# the lane in crapkit.toml
command = "python -m pytest -m 'not live and not perf' --cov=calc --cov-branch --cov-report=json:.crapkit/cov/py.json"
$ crapkit doctor
crapkit: lane 'py': positional argument 'live' narrows a full-suite coverage run; drop it, attach it to the flag it belongs to (-n8, --numprocesses=8), or set full_suite = false deliberately (cmd.exe does not treat ' as a quote: write the value in double quotes); a suite whose testpaths cannot be collected in one process needs one lane per testpath, each with full_suite = false and its own artifact
```
Write it `-m "not live and not perf"`. Carets, `&&` and `|` segments, redirections and
empty quoted arguments all read the way the shell reads them, so a chained lane
(`cd tests && python -m pytest --cov ...`) is checked one segment at a time. `doctor` reads
a lane the same way, and FAILs one whose runner will not start.
## Install
```
pip install crapkit
```
That is the release on [PyPI](https://pypi.org/project/crapkit/). For the unreleased tip
of `main`, or from a local clone (run at the clone root):
```
pip install git+https://github.com/JeanFrancoisGagne/crapkit.git
pip install .
```
Every route pulls one dependency, `lizard>=1.24.0`, a normal PyPI wheel, so an offline
mirror installs fine. Requires Python 3.11 or newer. The `pip install -e ".[dev]"` under
[Development](#development) is a different thing: it adds the test extra, for people
changing crapkit.
Scoring runs your own test command on your own machine and reads the artifact it writes.
There is no network call anywhere in crapkit, so no source, no score and no telemetry
leaves the box
([SECURITY.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/SECURITY.md)).
```
$ crapkit --version
crapkit 0.6.0
```
`python -m crapkit` works identically to the console script and is what to use from a
source checkout. Every subcommand accepts `--repo PATH` (default: the nearest `crapkit.toml`
at or above the current directory, so a monorepo workspace finds the root's), and with it
you never have to `cd` into the repo you are scoring; [Subcommands](#subcommands) shows
where the flag goes.
## Upgrading from 0.4.4
**Run `crapkit ratchet seed` first.** Shell cognitive complexity now nests, which is
analysis version 8, and marks measured under version 7 are not comparable. Until you
re-seed, `verify` refuses at exit 3:
```
$ crapkit verify
crapkit: ratchet marks were recorded under [crapkit-analysis=7 lizard=1.24.0] but this run measures [crapkit-analysis=8 lizard=1.24.0] — CRAP scores are not comparable across metric versions; re-baseline with `crapkit ratchet seed`
```
Only shell and PowerShell cognitive numbers move. `ccn` does not, so a re-seed re-stamps
the file and leaves the marks where they were.
Five more things change under you. Three of them need nothing from you:
- **New cache files.** `.crapkit/coupling-cache-v1.json` joins `churn-cache-v2.json` and
`churn-log-v2.z`. A warm 0.4.4 churn cache is adopted once and its file removed, and
`.crapkit/` is already gitignored, so nothing new reaches your index.
- **`trend` and `report` write.** Both read a per-run rollup table, filled once per run and
pruned with its run, instead of rescanning every scored row. A read-only `.crapkit/`
costs the speedup, never the command.
- **Nested scopes may move files.** One predicate decides scope ownership now, and the
deepest declared path wins, so a repo whose `[[scope]]` paths nest inside each other can
see files change scope, rollup and ceiling on the next scan. Scopes that do not nest see
no change.
The other two put something in front of you:
- **`mutate` keeps a worktree pool.** With `mutation_workers > 1` the worker worktrees now
live under `.crapkit/mutate-pool/` between runs and are re-prepared each run, which is
the setup cost gone (30.6 s to build four on a 31,459-file repo, 0.46 s to re-prepare
them). The pool is not size-bounded and nothing sweeps it: `crapkit mutate --drop-pool`
removes it and exits. Single-worker runs are untouched.
- **`doctor` WARNs on a lane with no `results_artifact`.** Every `coveragepy` or `istanbul`
lane written before 0.4.5 gets one, with the two lines that fix it. Coverage is
unaffected. What the lane cannot feed without a results file is the crashed-worker check
and the no-new-failures check (exit 8).
### The exe lock on Windows
`uv tool upgrade crapkit`, and `pip install -U` into a tool venv, fail with `os error 32`
("The process cannot access the file because it is being used by another process") while a
crapkit MCP server is live: an agent session spawns `crapkit.exe mcp`, which holds the
launcher, and Windows will not overwrite a running executable. The venv upgrades before
that copy fails, so `crapkit --version` already reports the new version and only the
launcher is stale. Quit the agent session and rerun the upgrade, or rename the locked exe
aside (Windows allows renaming a running one) and copy the new one in. Two lines in
cmd.exe, where both `%` variables expand:
```bat
move %USERPROFILE%\.local\bin\crapkit.exe %USERPROFILE%\.local\bin\crapkit.exe.old
copy %APPDATA%\uv\tools\crapkit\Scripts\crapkit.exe %USERPROFILE%\.local\bin\crapkit.exe
```
Git Bash has no `move` and passes `%APPDATA%` through as literal text, so that block
fails there on its first line. Its form is `mv` and `cp` over `"$USERPROFILE"` and
`"$APPDATA"`, which Git Bash sets to the same two directories.
## The Claude Code plugin
```
claude plugin marketplace add JeanFrancoisGagne/crapkit
claude plugin install crapkit@crapkit
```
Two commands, installed once per user, and every repo on the machine gets it. The plugin
ships three skills, the read-only MCP server, and one advisory PostToolUse hook that names
any function an edit pushed over its ceiling. Claude reaches two of the skills by itself,
`crapkit` and `crapkit-recover`; the third you type, as `/crapkit:crapkit-onboard`, because
wiring a repo up happens once and its description has no business in every turn's window.
It adds no files to your repo, and it needs the crapkit CLI on PATH.
A repo with no `crapkit.toml` costs a silent sub-50 ms no-op per edit. Other agent
runtimes have no marketplace: copy `plugin/skills/*` into their skills directory instead.
The hook registers on `Edit|Write`, which is every write that names a file. An agent that
writes its source through a shell heredoc names none, so a `Bash` event is judged off the
working tree instead. That half is yours to register, because it costs two
git spawns per shell call. Add a second PostToolUse entry to your own settings, same
command, matcher `Bash`:
```json
{
"hooks": {
"PostToolUse": [
{
"matcher": "Bash",
"hooks": [
{ "type": "command", "command": "crapkit claude-hook --protocol 1", "timeout": 20 }
]
}
]
}
}
```
The cost is one `git rev-parse --show-toplevel` and one `git status --porcelain -z -uall`
per shell call in any git repo, whether or not crapkit measures it: about 30 ms together
on crapkit's own checkout, and more on a bigger tree. What comes back is the dirty or
untracked `*.py` files written in the last 12 seconds, 25 at most, each judged the way an
edit is. Python only, so a TypeScript or Go repo pays the two spawns and hears nothing.
## Languages
14 languages, two coverage parsers. Coverage joins where a parser exists; everything else
scores on complexity alone.
| Language | Files | Coverage |
|---|---|---|
| Python | `.py` | coverage.py |
| TypeScript | `.ts` | istanbul |
| TSX | `.tsx` | istanbul |
| JavaScript | `.js` `.jsx` `.mjs` `.cjs` | istanbul |
| Vue | `.vue` | istanbul, when your vitest run reports on `.vue` files |
| Swift | `.swift` | none: cc-only |
| Go | `.go` | none: cc-only |
| Rust | `.rs` | none: cc-only |
| shell | `.sh` `.bash` | none: cc-only |
| PowerShell | `.ps1` `.psm1` | none: cc-only |
| C and C++ | `.c` `.cc` `.cpp` `.cxx` `.h` `.hpp` | none: cc-only |
| Objective-C | `.m` `.mm` | none: cc-only |
| Java | `.java` | none: cc-only |
| Zig | `.zig` | none: cc-only |
A cc-only scope declares `coverage_optional = true`, scores `crap = ccn`, and needs no
lane. Nothing about it is provisional: the ceiling still binds and the gate still refuses
a function over it. Add a coverage lane the day a parser exists and the same scope starts
joining coverage.
`crapkit init` writes that key itself, on every scope whose languages all lack a parser,
and leaves it off any scope a lane could still measure. So the 60-second start above runs
unchanged on a Go, Rust or shell repo: `crapkit coverage` scores it with no lane at all,
and that run is the baseline `worklist`, `next-item`, `ratchet seed` and `verify` read.
Three readers are crapkit's own. lizard ships none for shell or PowerShell, so crapkit
counts their functions itself. Its Rust reader scores a 7-arm `match` as ccn 2 (filed as
lizard #494), so crapkit counts each non-wildcard arm like a C `case` and retires the
override the day upstream fixes it. The cognitive column charges that same block once,
the way Sonar charges a `switch`.
## The gate
Four surfaces ask the same question, ccn against the scope's ceiling, with four
different powers:
| Surface | Fires | Power |
|---|---|---|
| `crapkit claude-hook` | after an agent's edit lands | **advisory.** Names the breach on stderr. Blocks nothing, because PostToolUse runs after the write |
| `crapkit rescore FILE --gate` | when you ask, after the first coverage run | **preview.** The commit gate's verdict on demand, sub-second, before you stage. With no run behind it, exit 1 and `no snapshot` |
| `crapkit hook-precommit` | `git commit` | **blocks.** The hook exits 6; git reports 1. Staged blobs only, so it costs the size of the commit and needs no coverage |
| `crapkit verify` | before you push, and in CI | **the verdict.** Gate, ratchet, new test failures, diff coverage, against the trusted baseline |
Both hooks exempt a function the committed ratchet already carries a mark for, so touching
signed debt never refuses a commit. `verify` is what fails a mark that rises. Since 0.4.5
its gate exempts a touched function whose fresh CRAP sits **at or under** its mark, the
rule `rescore --gate` already applied; push it past the mark and the gate fires again. The
pre-commit hook still exempts on the mark's existence alone, on purpose: a staged blob has
no coverage, so there is no fresh CRAP to compare against. It reports each exemption count
on stderr (`staged function(s) carry a ratchet mark and were not gated`), and says the same
about a staged file no `[[scope]]` claims, so a new top-level directory cannot go ungated
in silence.
**The crapkit root does not have to be the git top.** Since 0.4.5 every git spawn runs with
`diff.relative=true` and `core.quotePath=false`, so a `crapkit.toml` in `packages/api`
gates that package's own staged files and names them `app/m.py`, not
`packages/api/app/m.py`, and a dirty non-ASCII path is a real row rather than an invisible
one. Before that a nested root matched staged paths against no scope, and a function at
twice the ceiling committed with a warning.
Git runs hooks outside your shell's activated venv. Bare `python` must resolve to an
interpreter that has crapkit installed, or spell it out
(`exec /path/to/venv/Scripts/python -m crapkit hook-precommit`).
### Route 1: `.git/hooks/pre-commit` (local, not committed)
```sh
cat > .git/hooks/pre-commit <<'EOF'
#!/bin/sh
exec python -m crapkit hook-precommit
EOF
chmod +x .git/hooks/pre-commit
```
The same file from PowerShell. `Out-File` and `>` write a byte-order mark (UTF-16 on
5.1) in front of the shebang, and git then answers every commit with `cannot spawn
.git/hooks/pre-commit` and lets it through; `Set-Content -Encoding ascii` does not. Git
runs the hook with its own `sh`, so the interpreter is spelled with forward slashes and
quoted, and no `chmod` is needed on Windows:
```powershell
$python = (Get-Command python).Source -replace '\\', '/'
Set-Content -Path .git/hooks/pre-commit -Encoding ascii -NoNewline -Value "#!/bin/sh`nexec '$python' -m crapkit hook-precommit`n"
```
`crapkit doctor` warns when the hook file git would spawn starts with a byte-order mark.
### Route 2: a committed hooks directory
The whole route, from a repo that has no `githooks/` yet:
```sh
mkdir -p githooks
cat > githooks/pre-commit <<'EOF'
#!/bin/sh
exec python -m crapkit hook-precommit
EOF
chmod +x githooks/pre-commit
printf 'githooks/pre-commit text eol=lf\n' >> .gitattributes
git add .gitattributes githooks/pre-commit
git update-index --chmod=+x githooks/pre-commit
git commit -m "add crapkit gate hook"
git config core.hooksPath githooks
```
**The `--chmod` goes between the `add` and the `commit`.** It writes the executable bit to
the index, so a commit that already happened does not carry it: run it after and `git
ls-tree HEAD` still says `100644`, which is a hook Unix checkouts silently skip. The
`.gitattributes` line is the harder half of the same failure: under Windows' default
`core.autocrlf` the hook checks out CRLF and `#!/bin/sh\r` dies on Linux and macOS with a
bad-interpreter error. `crapkit doctor` warns when a file under `core.hooksPath` is not
`100755` in the index and prints the `update-index` line for it.
Git will not read a hooks path out of a committed file, so that `git config` line belongs
in your CONTRIBUTING setup steps. Every clone arms the gate with it.
### Route 3: the pre-commit framework
crapkit ships a `.pre-commit-hooks.yaml` declaring `id: crapkit-gate`. In your
`.pre-commit-config.yaml`:
```yaml
repos:
- repo: https://github.com/JeanFrancoisGagne/crapkit
# crapkit's release step rewrites this line to the tag it just cut
rev: v0.6.0
hooks:
- id: crapkit-gate
```
That file arms nothing on its own. The framework writes `.git/hooks/pre-commit` when you
tell it to, and until then `git commit` runs no gate and says nothing:
```sh
pip install pre-commit
pre-commit install
```
`pre-commit install` is the line every clone needs, the way Route 2 needs its
`git config core.hooksPath` line.
`rev` is a git ref pre-commit resolves against that remote. Pin a release tag, not a
branch: `pre-commit autoupdate` only moves between tags, and a moving `main` would change
your gate under you.
### Route 4: CI
A CI job runs on a fresh clone, which has no `.crapkit/` store, so bare `crapkit verify`
exits 1. Running `coverage` first would make the PR's own tree the baseline, a gate that
can never fail. The portable baseline is the mechanism:
```
# on the default branch, after a passing verify: commit this file
crapkit verify --emit-baseline crapkit-baseline.tsv
# in the PR job, against the committed baseline
crapkit verify --baseline-tsv crapkit-baseline.tsv --github
```
`--github` emits `::error file=...` annotations that land on the PR diff; `--sarif PATH`
writes SARIF 2.1.0 for code-scanning upload. Refresh the committed baseline whenever the
default branch's verify passes.
Two things the job has to do before those lines run. **Install crapkit**, `pip install
crapkit`, and pin the version the way Route 3 pins `rev`: an unpinned install moves your
gate on whatever day a release lands. **Fetch the whole history.** `actions/checkout`
clones one commit by default, `verify` reads the diff against the baseline's commit out of
git, and a shallow clone does not have that commit:
```
$ crapkit verify --baseline-tsv crapkit-baseline.tsv
crapkit: baseline commit a74260f321f is not an ancestor of HEAD in this shallow clone, which does not hold it; set fetch-depth: 0 on the checkout or run git fetch --unshallow
```
That is exit 4 on a `git clone --depth 1` of a repo whose baseline verifies at full depth.
On a full clone the same exit blames what it used to, a rebase or an amend that rewrote
history, and asks for a fresh baseline instead.
Set `fetch-depth: 0` on the checkout step, which is what crapkit's own
[.github/workflows/ci.yml](https://github.com/JeanFrancoisGagne/crapkit/blob/main/.github/workflows/ci.yml) does.
The whole PR job, on GitHub Actions:
```yaml
on: pull_request
jobs:
crapkit:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v4
with:
fetch-depth: 0 # verify needs the baseline's commit
- uses: actions/setup-python@v5
with:
python-version: "3.12"
- run: pip install crapkit
- run: pip install -e ".[dev]" # your own test dependencies
- run: crapkit verify --baseline-tsv crapkit-baseline.tsv --github
```
The second install is the one people leave out. `verify` reruns your lanes, so the job
needs whatever your test command needs: the coverage plugin, `npm ci`, a database, all of
it. Without them the lane writes no artifact and `verify` exits 5 quoting the runner's own
error, which is a broken job and not a verdict.
### What a refusal looks like
```
$ git commit -m "add route"
crapkit gate: 1 staged function(s) exceed the complexity ceiling of 6:
ccn 7 app/m.py:9 route( a , b , c , d )
decompose before committing (coverage cannot save a function above the target).
```
That commit exited **1**, not 6. Git collapses any failed hook to 1, so 6 is a code you
only ever see by running the hook yourself: `crapkit hook-precommit` exits 6 on a
violation and 0 otherwise. The stderr block above is the same either way.
`CRAPKIT_OVERRIDE_REASON` is not a bypass. Setting it routes the commit through the full
three-record audit: an alert line through `alert_command`, a ratchet entry staged into the
commit, and a row in the override log. All three land or nothing does, and an unset
`alert_command` refuses the override outright. See
[docs/ratchet.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/ratchet.md#overrides-and-the-audit-trail).
## The GitHub Action
[action.yml](https://github.com/JeanFrancoisGagne/crapkit/blob/main/action.yml) at this repository's root is a composite action, so a reviewer
sees crapkit's numbers on the pull request without installing anything. Four lines add it
to a workflow, and every input has a default:
```yaml
- uses: actions/checkout@v4
with:
fetch-depth: 0
- uses: JeanFrancoisGagne/crapkit@v0.6.0
```
The whole job those four lines sit in:
```yaml
on: pull_request
jobs:
crapkit:
runs-on: ubuntu-latest
permissions:
pull-requests: write # the comment, and nothing else
steps:
- uses: actions/checkout@v4
with:
fetch-depth: 0 # the diff, and verify's baseline commit
- uses: actions/setup-python@v5
with:
python-version: "3.12" # the interpreter the install below lands in
- run: pip install -e ".[dev]" # whatever your lanes need to run
- uses: JeanFrancoisGagne/crapkit@v0.6.0
with:
gate: "false"
```
That `pip install` step is the one people leave out, and it is the same one Route 4 above
names: the action installs crapkit and nothing else, so your lanes still need whatever
your test command needs. Without it the lane writes no artifact and the comment says so.
`fetch-depth: 0` is the other one. `actions/checkout` clones a single commit; the action
reads the pull request's changed files out of git and `verify` reads the diff against the
baseline's commit. With a shallow clone the file list comes back empty and the comment
ranks the whole repository instead of the diff.
The action installs crapkit from `$GITHUB_ACTION_PATH`, which is its own checkout of the
ref you pinned in `uses:`. So a pin left at last month's tag scores your tree with last
month's crapkit rather than with whatever released since, and pinning a tag is the whole
version policy; the snippets above name the current release.
### What the comment looks like
One comment per pull request, edited in place on every push. A hidden
`<!-- crapkit-action -->` line is how the next run finds it, so a fifteen-push branch
carries one comment and not fifteen. On a `push` event there is no pull request to carry
it, and the same text goes to the job log instead.
Rendered from three saved payloads: a pull request that adds an untested `route()` (ccn 8)
beside a ratchet-marked `legacy_router()`, in a repository whose `diff_uncovered_max` is 3.
The payloads are under `tests/fixtures/action_comment/`, and the unit suite pins this block
to their render:
```markdown
<!-- crapkit-action -->
## crapkit
4 functions in 2 files, 2 over ceiling 6, CRAP load 149.59, grade F.
**verify failed, exit 6: complexity gate.**
- gate: `app/calc.py:34` `route( a , b , c , d )` ccn 8, cov 0%, crap 72.0 -> decompose
- uncovered lines in `app/calc.py`: 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45
Run 3 against baseline 1, 1 changed file: 1 gate violation, 0 ratchet regressions, 0 new test failures, 11 uncovered changed lines.
### Worklist: 1 changed file
| File | Function | ccn | risk | remedy |
|---|---|---:|---:|---|
| `app/calc.py:34` | `route( a , b , c , d )` | 8 | 4.0 | decompose |
| `app/calc.py:19` | `legacy_router( a , b , c , d , e )` | 8 | 4.0 | decompose (accepted debt) |
```
The first line is the run `crapkit coverage` wrote: functions and files, how many sit over
the ceiling (`over ceiling 6`, or `over their ceilings (6; reports 12, util 4)` when scopes
set their own), CRAP load and grade, with a failed lane's first error line appended as
`; lane 'js' failed: ...`. When `coverage --json` died before a summary, the line quotes the
error object it printed instead: `` `crapkit coverage` exited 5: lane 'py' cannot import
pytest-cov; pip install pytest-cov. ``
The verdict opens with the exit code and the rule it stands for (`complexity gate`,
`ratchet regressions`, `new test failures`, `diff-coverage ceiling N`), then one bullet per
finding: each gate violation with its function, ccn, coverage, CRAP and remedy; each
ratchet regression as recorded -> fresh; each new test failure by id; and the first twenty
uncovered changed lines, one bullet per file, with a count of the rest. The counts line
closes it. A verify that passed is one line: `**verify passed.** Run 2 against baseline 1,
7 changed files.`
The rows are the ranked worklist for the files the pull request changed, worst first,
`top` of them, with the rows a finding names listed first. `risk` is ccn times churn
weight, the number `crapkit worklist` ranks on, and `remedy` is the run's own verdict for
that function: `decompose`, `add-tests` or `ok`. `(accepted debt)` marks a function the
committed ratchet carries a mark for, so an untouched `legacy_router` does not read like
the pull request's own new function. A pull request that touches no ranked function gets
the heading and no table.
The two file counts describe the same diff, counted twice. `39 changed files` is
`git diff --name-only base.sha...HEAD`, the branch's own commits, and it is what the
table is filtered to. The count on the verdict line is what `verify` measured from the
same fork point. With `delta: "false"` the second one is 0, because there is nothing
behind the checkout to measure from.
### The inputs
| Input | Default | What it does |
|---|---|---|
| `gate` | `"false"` | `"true"` exits with `crapkit verify`'s own code, so a finding fails the check. On a pull request with `delta` on it also exits 1 when the base run was not made, because a verdict with no base run judged no changed function. Anything else exits 0 and the comment is the whole output |
| `delta` | `"true"` | scores the pull request's base commit first, so the verdict covers the commits the pull request adds. Costs a second lane run; `"false"` scores the checkout alone, and the verdict then judges no changed function |
| `top` | `"5"` | worklist rows rendered in the table |
| `python-version` | `"3.12"` | the interpreter `actions/setup-python` installs crapkit into. Match it to the version your own setup-python step named, or the lanes run on an interpreter your dependencies never reached |
`gate: "false"` is the default on purpose. A team adopts the action before it has decided
which findings should stop a merge, and a check that fails on day one gets turned off on
day two.
### What the verdict line covers
On a pull request, the commits the pull request adds. The action scores the fork point
first, then the checkout, then runs `crapkit verify --base <fork>`, which measures the
diff from there and takes the fork point's run as its baseline. So the gate judges the
functions in the diff a reviewer is reading, and a repository that was already over its
ceiling before the branch started does not fail every pull request that touches it.
The fork point is `git merge-base` of `base.sha` and HEAD, not `base.sha` itself.
`base.sha` is the base branch's tip when the event fired, so a base branch that moved
after the branch forked carries commits HEAD never saw, and a run there would be neither
the baseline verify wants nor a diff anyone is reviewing.
The base run happens in a detached worktree under `RUNNER_TEMP`, and its store is copied
over the checkout's so both runs sit in one place. The cost is **two lane runs on a pull
request**: your suite runs once at the fork point and once on the checkout. Set `delta:
"false"` to skip the base run, and the verdict falls back to the checkout against its own
run, which reports the tree's own health and judges no changed function. The comment says
so in place of `verify passed`:
```markdown
**verify judged no changed function:** the base run was not made (no base commit). Run 2 against baseline 2, 0 changed files.
```
Three things leave the base run unmade: a shallow clone that does not hold the fork
point, a fork point older than your `crapkit.toml`, and a lane that will not run against
that tree. The step logs `crapkit base scoring exited N` and writes the reason to
`crapkit-base.reason` in the words the comment then quotes, `shallow clone does not hold
the fork point of <sha>; set fetch-depth: 0 on the checkout`, `no usable crapkit.toml at
the fork point <sha>: ...`, or `lane failed at the fork point <sha>: ...` with the lane's
first error line. The verdict falls back the same way `delta: "false"` does, and the
ratchet still runs, so exit 7 there is a finding. What differs is the job's status. With
`gate: "true"` on a pull request whose base run was attempted and not made, the exit step
exits 1 and prints the reason, because `actions/checkout`'s default depth-1 clone would
otherwise turn every pull request into a green check that judged nothing. A `push` event
and `delta: "false"` never attempt the base run, so they keep verify's own code; a `push`
has no base commit and no pull request to comment on.
One requirement the base run adds: the lane has to measure the tree it runs in. A lane
that reaches an installed copy of your package instead of the checkout will measure the
pull request's code while standing on the base commit, and the two runs then describe the
same tree. `crapkit verify` refuses a run whose artifact names files outside the tree
(exit 5), which catches the loud version of this; a lane pinned to a path outside the
worktree is the quiet one. Point the lane at the tree, or set `delta: "false"`.
`--reuse-artifacts` is what keeps each of those runs to one pass of your suite. `coverage`
ran the lanes moments earlier on that tree, and verify parses those artifacts rather than
running the whole suite a second time for the same numbers.
Which is why `crapkit coverage` has to exit 0 for there to be a verdict. When it exits
anything else (a lane that failed, an artifact it refused), the action does not run
`verify`: on a runner that keeps its workspace between jobs (`clean: false`), a
`verify --reuse-artifacts` over a failed measurement read the artifact the dead lane had
left from an earlier run, passed over it, and made that run the trusted baseline. The
comment then carries coverage's failure in place of the verdict:
```markdown
**no verdict: `crapkit coverage` exited 5 (lane 'py' failed: lane 'py' wrote no artifact on its last attempt; the .crapkit/cov/py.json on disk predates it); verify did not run.**
```
The parenthesis is the first line of the lane failure the summary carries. When every
lane failed, `coverage` prints no summary at all and the lane errors are only in the job
log, and the line says so. With `gate: "true"` the job exits with coverage's code.
The other gate that judges a delta is the portable baseline in [Route 4](#route-4-ci):
commit `crapkit-baseline.tsv` on the default branch and run `crapkit verify --baseline-tsv
crapkit-baseline.tsv` in a step of your own. It needs no second lane run, and it needs
someone to keep that file current.
The comment is posted with `gh api` and the job's own `GITHUB_TOKEN`, which needs
`pull-requests: write`. Two things it cannot do: a pull request from a fork gets a
read-only token, so the POST is a 403 there, and a self-hosted runner without the `gh` CLI
on PATH fails that step. Both leave the rendered text in the job log.
## Subcommands
Every subcommand takes `--repo PATH`, and the flag goes **after** the subcommand. Without
it the root is the nearest `crapkit.toml` at or above the current directory
([ADR 0002](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/adr/0002-configuration-is-found-upward-nearest-wins.md)): from a
monorepo workspace `crapkit worklist` reads the root configuration that claims the
workspace, says `crapkit: using crapkit.toml at /repo` on stderr, and reads a relative path
argument from where you stand. `claude-hook` is the one exception: it has no `--repo`,
because it takes its root from the file named in the hook payload it reads.
```
$ crapkit worklist --repo /path/to/repo --scope util --top 1
worklist @ a7c5c85ac37 (run 1, floor ccn>=5, churn 12mo) - 1 of 3 active (--top 1), 0 dormant
risk 5.4 ccn 5 crap 30.0 cov 0% 5c/1a util/stats.py:1 bucket( value , low , high )
```
Before it, argparse reads the path as the subcommand name and exits 2 without ever
mentioning `--repo`:
```
$ crapkit --repo /path/to/repo worklist --top 1
crapkit: error: argument command: invalid choice: '/path/to/repo' (choose from 'inventory', 'coverage', ...)
```
`--json` prints one sorted-keys JSON object on stdout, always carrying a `schema` field.
| Command | What it does |
|---|---|
| `init` | Sniffs tracked source into per-directory scopes, writes a self-validated starter `crapkit.toml` whose lanes report into `.crapkit/cov/`, and appends `.crapkit/` plus each runner's own droppings to `.gitignore`. Writes a live `[[lane]]` when it can detect the test runner, otherwise a commented template. Refuses to clobber an existing config. |
| `doctor [--show-files] [--json] [--tune] [--plugin-root [PATH]]` | Checks the config still describes the repo: unknown keys (with the accepted spellings), zero-file scopes, tracked source no scope claims, scopes no lane covers, lane cwds and commands that no longer resolve, lizard importable, oversized files. It reads each lane command with the shell that will run it, so a quoted interpreter path is one word and a runner after `&&` is checked too, and it FAILs a lane whose runner does not resolve or that the shell cannot start, naming the word to change; a bare name is looked for on PATH and a runner spelled as a path is looked for under the directory the lane runs in, so `.venv/bin/python` answers the same from any directory you run `doctor` in; each distinct runner is probed once, not once per lane. It WARNs on a lane writing its artifact at the repo root, a `coveragepy` or `istanbul` lane with no `results_artifact` (the crashed-worker and no-new-failures checks are off for it, whichever runner the lane spells), a committed hook under `core.hooksPath` that is not executable in the index, a directory whose functions are all `untested` while its tests exist, and a scope a lane measures with no `[crapkit.scoped_tests]` template behind it, which is the loop's step 4 with nothing to run. `--tune` prints suggested parallelism knobs and writes nothing. `--plugin-root PATH` reads no repo at all: it checks an installed [plugin](https://github.com/JeanFrancoisGagne/crapkit/tree/main/plugin) against the `crapkit` on PATH (the bare name its hooks and MCP server spawn) on both version and hook `--protocol`, and FAILs when PATH carries no `crapkit` at all, one line per disagreement and silence when they agree; PATH is the plugin root or any directory above it, `~/.claude` included (only manifests named `crapkit` count, and the newest install wins), and with no PATH it looks in Claude Code's plugin cache. A root it found rather than one you typed is named first, as `crapkit doctor: checking PATH`. See [docs/agent-json.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/agent-json.md#doctor---json). |
| `inventory [--db PATH] [--export PATH] [--json]` | One lizard pass over every in-scope file into a SQLite snapshot run, cached by content hash. `--db` is the only way to point crapkit at a store outside `.crapkit/`, and only this command accepts it. |
| `coverage [--lane NAME] [--reuse-artifacts] [--reuse-unchanged] [--export PATH] [--sarif PATH] [--github] [--json]` | Runs the lanes, joins branch coverage onto a fresh inventory, writes a scored run. A failed lane is recorded, not fatal: its scopes fall back to `no-lane` and the run is typed `partial`, so it can never serve as a baseline. See [docs/lanes.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/lanes.md). |
| `verify [--baseline ID \| --base REF \| --baseline-tsv PATH] [--emit-baseline PATH] [--override REASON] [--reuse-artifacts] [--reuse-unchanged] [--no-tighten] [--sarif PATH] [--github] [--json]` | The full verdict against the trusted baseline: gate on touched functions, ratchet, no new test failures, optional diff-coverage ceiling. The three baseline selectors are mutually exclusive; `--baseline ID` also bypasses the taint rule ([The trusted baseline](#the-trusted-baseline)), and `--baseline-tsv` reads a commit-stamped file so a fresh clone verifies with no store. `--no-tighten` passes the verdict without rewriting the ratchet. Findings a dirty tree produced are tagged `dirty` and counted apart. It reads each istanbul artifact once for coverage, dead lines and its digest, and skips the artifact walk on an empty diff; skipping the whole run on an unchanged tree was measured and rejected, because a key made of HEAD plus the dirty names cannot see a second edit to a file that was already dirty. |
| `worklist [--top N] [--scope NAME] [--batches N] [--json]` | The risk map: every admitted function ranked by `ccn * churn weight`, floored by `worklist_floor`, with hot simple code and anything over its ceiling admitted past that floor. It ranks finished rows and `no-lane` rows too, marked `ok` and `no-lane`, so it never empties; `next-item` carries the stop condition. Every row carries the function's `crap` and `cov` off the ranked run and its `ratchet_mark` when the committed marks file signs for it, and the header counts the active rows the cap hid: `50 of 3980 active (worklist_top 50)`. `--scope NAME` (repeatable) is exact, not a substring; a name no `[[scope]]` declares is a configuration error, exit 3, naming the declared scopes. `--batches N` **adds** a `batches[]` view cutting the active list into at most N file-disjoint batches with co-changing files kept together, off the same cached pairs `coupling` reads; the normal keys stay. |
| `next-item [--top N] [--exclude FRAG] [--scope NAME] [--claim]` | The actionable queue as JSON, with churn, budget estimates and uncovered lines. Same run and same admission floor as `worklist`, a different view of it: `no-lane` rows are skipped and counted in `skipped_no_lane`, and what is left is ranked by `crap` descending rather than by risk, so the item it hands out is often not the worklist's first row. `--exclude FRAG` (repeatable) skips items whose path or function name contains FRAG; `--scope NAME` (repeatable) is exact, not a substring, and a name no `[[scope]]` declares is a configuration error, exit 3, naming the declared scopes. `--claim` holds what it hands out so a second session skips it. `stale` is true when the ranked run's commit is not HEAD, the same field `worklist` carries. Every item carries a `handle`: the bare identifier, or `(anonymous)#N` for a function with no name, which is the name form that survives the edit the item asks for. |
| `claims [list \| release PATH NAME \| release --all] [--json]` | The open claims, and the way to hand one back without waiting for a verify. `release` takes the bare identifier, the whole long name, or the `handle` the claim was taken under, which is the only one that picks out a single `(anonymous)` claim. |
| `brief FILE NAME [--batch N] [--json]` | The start-editing packet for one function: its own `source` text, every function in the file, the scored row and the scope ceiling, the ratchet mark and what the gate will bind on, uncovered lines, duplication twins, file churn, coupling partners, the config's notes, and the literal commands for the rest of the loop. Plus `handle`, `remedy` and the same `est_splits` / `est_uncovered_paths` the queue prints, and a `commands.refresh` that writes a run (`refresh_writes_run`) rather than re-reading the stale one. `NAME` takes the bare identifier, the long name `next-item` printed, the function's start line, `(anonymous)#N` for a function printed `(anonymous)` counting the file's anonymous functions from the top, or `NAME#2` for the second of several functions a file gives one name to. `--batch N` drops the positionals and emits `packets[]` instead: the top N of the queue, built from one read of the store and one duplication pass over the snapshot for the whole batch (batch of 5: 11.8 s to 5.2 s, output byte-identical to five separate calls). |
| `explain FILE NAME [--history] [--tests] [--json]` | A function's score across runs plus its mark. `NAME` resolves exact first: a function whose bare identifier or long name is exactly `NAME` wins, and only when nothing matches exactly does it fall back to a prefix match, so `route` explains `route` rather than every `route_*` beside it. It also takes the function's start line, the form `brief` takes, which is how you open one printed `(anonymous)`. `--history` adds the commits that touched it (`git log -L`), each carrying its message `body`, `--tests` the tests that covered it, which needs coverage.py contexts turned on ([recipe](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/lanes.md#test-attribution-for-explain---tests)). `--json` emits the same content as one `schema` 1 object. |
| `rescore FILE ... [--gate] [--json]` | Fresh complexity for named files over the latest run's stale coverage, joined by name. Advisory: it writes no run. `--gate` applies the pre-commit hook's policy to the same selection the hook uses (functions the tree changed since HEAD), minus functions whose CRAP sits at or under their ratchet mark, and exits 6. A marked function past its mark is gated; the pre-commit hook exempts on the mark's existence instead, because a staged blob has no coverage to score. |
| `ratchet seed \| prune \| merge \| move \| report [--enforce] [--json]` | The mark lifecycle: seed new debt, prune gone code (a mark whose file git renamed follows it), merge as a git driver, move re-paths marks, report reads burn-down from the file's own git history. See [docs/ratchet.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/ratchet.md). |
| `runs [list \| prune [--keep N]] [--json]` | Run history, and retention. `list` marks the run `verify` compares against today `baseline`, and prints `verdict=-` for a run that produces no verdict rather than one that failed. See [The trusted baseline](#the-trusted-baseline). `--keep` (default 5) is a floor on the newest trusted runs, not a cap: the digest pair, every passing verify baseline, every run an override names, and the newest non-hook run are kept too. `prune` VACUUMs afterwards. |
| `overrides [--json]` | The override audit trail: who granted what, when, and why. |
| `trend [--json]` | Totals per trusted run: functions, over-target count, CRAP load, average, per-scope rollup. It reads a per-run rollup table rather than rescanning every scored row, and fills that table for any run missing one, so it writes to the store (best effort: a read-only `.crapkit/` costs the speed, not the command). |
| `digest [--alert]` | The delta between the two newest runs with identical lane sets. Silent when nothing changed. `--alert` pipes the body to `alert_command` on stdin. Plain lines, never JSON. |
| `report [--out PATH]` | One self-contained HTML page written to `.crapkit/report.html` (or `--out PATH`, repo-relative, or an absolute path you name), with the path printed on stdout. It renders what `worklist --json` and `trend --json` already answer at their defaults: the ranked worklist capped at `worklist_top`, the per-scope grades off the newest run, the trend series, and a banner naming every stale lane. It measures nothing and opens no network connection. Every row carries the function's CRAP and coverage, and prints the `crapkit explain` call for the rest: dark lines, history, the mark. It reads the same per-run rollups `trend` does, and writes them on the same terms. |
| `duplication [--min-lines N] [--similarity F] [--top N] [--json]` | Near-duplicate functions by normalized line shingles with containment scoring. Defaults: `--min-lines 8`, `--similarity 0.8`, `--top 50`. `--top` truncates the list. A function and a function nested inside it never pair: their spans nest, they score 1.0 by construction, and nobody can deduplicate a factory from its own closure. |
| `coupling [--min-support N] [--min-confidence F] [--top N] [--json]` | File pairs that keep landing in the same commits. Defaults: `--min-support 5` shared commits, `--min-confidence 0.5` max-direction ratio, `--top 50`. Bulk commits never couple pairs, and a young repo returns nothing at the default support. The ranked pairs are cached in `.crapkit/coupling-cache-v1.json`, keyed on HEAD, the churn window, today's UTC date, the path format and a digest of the tracked set, and shared with `brief` and `worklist --batches` (warm: 1.05 s to 0.11 s on a 72k-commit repo). The date is part of that key, so the first run after midnight UTC rebuilds the pairs on an unchanged HEAD. `--top` reads the cache, because it truncates that same order; `--min-support` or `--min-confidence` off their defaults ask a wider question than the file answers, so they bypass it and recompute. |
| `mutate [--files F ...] [--max-mutants N] [--drop-pool] [--json]` | Diff-scoped mutation testing: flips comparisons, boundary shifts, boolean connectives and boolean literals on changed lines, runs `mutation_command` per mutant, lists survivors. `--files` replaces diff scope with the whole file. Both lists pass through the scored corpus first, the same predicate `coverage` uses (scopes, excludes, the test-file cut, `max_file_bytes`): a test file, an excluded path, a file over `max_file_bytes` or a file no scope claims is named on stderr and never mutated, `--json` lists it under `outside_corpus`, and when nothing is left stdout says `nothing to mutate` at exit 0 without starting the suite. `--max-mutants` (default 100) caps the run and the cap warning goes to stderr only, so `mutants` in `--json` is the capped count. Shell and PowerShell files are refused by name on stderr rather than mutated: `<` and `>` are redirections there, not comparisons. With `mutation_workers > 1` the worker worktrees are kept at `.crapkit/mutate-pool/` and re-prepared per run (30.6 s to build four on a 31,459-file repo, 0.46 s to re-prepare them); `--drop-pool` removes them and exits. |
| `test-scoped FILE ...` | Runs each owning scope's `[crapkit.scoped_tests]` template on the files (quoted, longest-prefix scope wins). A template with no `{files}` runs as written, which is how a scope whose tests live outside its own paths runs its whole suite. Exit code only; a nonzero runner exits 1. |
| `hook-precommit` | The cc-only gate on staged blobs. No coverage, no snapshot, no repo-wide cache. Exit 6 on a violation. |
| `claude-hook [--protocol N]` | Reads one Claude Code PostToolUse payload from stdin and judges the file it edited: ccn against the scope ceiling, on functions the edit changed, minus functions a ratchet mark already covers. Advisory only: the edit has landed, and `hook-precommit` stays the enforcement point. Exit 2 and an advisory on stderr is the only thing it ever says, one block per judged file (a head line, one line per breaching function, a closing line): no `crapkit.toml` above the edited file, an unscoped file, mid-rebase or mid-merge, a `--protocol` other than 1, source that parses to no functions, or any internal failure all exit 0 in silence. The root is the first `crapkit.toml` above the edited file; the walk stops at a `.git` entry, so a worktree never borrows its parent's config. A `Bash` event names no file, so it judges the working tree instead: the dirty or untracked `*.py` files touched in the last 12 seconds, 25 at most, each through the same ladder, and silence for a clean tree or a cwd outside any repo. That half fires only where you register a `Bash` matcher ([The Claude Code plugin](#the-claude-code-plugin)). It opens no snapshot and writes nothing. |
| `watch [--interval SECONDS] [--cycles N]` | Rescores tracked files as they change (mtime polling, default 2s, subprocess-isolated so a half-saved syntax error never kills the watcher). `--cycles N` polls exactly N times and exits 0; without it the loop runs until ctrl-c. |
| `help [TOPIC]` | The help git, npm and docker answer to. With no TOPIC it prints the command list; with one it prints that subcommand's own help, the same page as `crapkit TOPIC --help`. A TOPIC that names no subcommand exits 3. |
| `mcp` | A dependency-free stdio MCP server (newline JSON-RPC 2.0) exposing twelve read-only tools named `verb_noun`, each with a title and a documented output schema. Every tool shells to the CLI's own `--json` surface, so the MCP view cannot drift from what the CLI reports. Answering from a kept in-process store was benchmarked and rejected: a packet's `source` would go stale behind the edit it describes. See [docs/agent-json.md](https://github.com/JeanFrancoisGagne/crapkit/blob/main/docs/agent-json.md#mcp-server). |
## Reading the output
### Flags: why a coverage number is missing
| Flag | Meaning | Scored |
|---|---|---|
| `measured` | A lane artifact spoke about this function. | Real `cov`. |
| `untested` | A lane covers the scope, but its artifact is silent on this function, which normally means no test imports the file. | `cov = 0`. A testing gap, and `uncovered_lines` comes back `null` because no artifact can name lines it never saw. |
| `no-lane` | No lane's `scopes` list names this function's scope. | `cov = 0`. A tooling gap, not a testing gap. `next-item` never hands one out and counts them in `skipped_no_lane`; `worklist` ranks them and marks the row `no-lane`, because a wiring gap is a risk you have to see. |
| `cc-only` | The scope sets `coverage_optional = true`, so no coverage number can exist. | `crap = ccn`, and `remedy` can only be `ok` or `decompose`. `uncovered_lines` comes back `null` with a note naming that setting. |
The coverage summary counts all four as `measured` / `untested` / `no_lane` / `cc_only`.
### Remedy: what to do about it
| Remedy | Condition | Action |
|---|---|---|
| `decompose` | `ccn > ceiling` | Split it. No amount of coverage clears this. |
| `add-tests` | `ccn <= ceiling` and `crap > ceiling` | Cover the branches. |
| `ok` | `crap <= ceiling` | Nothing. |
### Grade and CRAP load
The grade is the share of functions over their ceiling: `A+` at exactly zero, `A` under
2%, `B` under 5%, `C` under 10%, `D` under 20%, `F` at 20% or more. `crap_load` beside it
is the plain sum of every function's CRAP score, so it moves when a function gets better
even if the letter does not.
### Risk: what ranks the worklist
`risk = ccn * churn weight`. The weight is a time-weighted sum over the file's commits in
the churn window: each commit contributes a logistic weight rising to 0.5 for the newest
commit in the log and falling to near zero for the oldest, so five edits last month
outrank fifty from two years ago. The window anchors on the newest commit, never on the
wall clock, so a fixed tree ranks identically forever.
Age is not the input, position in the log is. A log whose commits all share one timestamp
has no range to weight against, so each commit counts once: a one-commit repo weighs every
file 1.0, ranks by ccn, and promotes nothing under the floor, because a top 10% of equal
weights would be every file. Commits minutes apart already rank. This repo was eight
commits old, all made the same day:
```
$ crapkit worklist --scope util
worklist @ a7c5c85ac37 (run 1, floor ccn>=5, churn 12mo) - 3 of 3 active (worklist_top 50), 0 dormant
risk 5.4 ccn 5 crap 30.0 cov 0% 5c/1a util/stats.py:1 bucket( value , low , high )
risk 4.5 ccn 9 crap 90.0 cov 0% 1c/1a util/curve.py:1 curve( scores , mode , floor , ceiling , skip_none )
risk 4.3 ccn 4 crap 4.2 cov 75% 5c/1a util/stats.py:13 spread( values , cap ) ok
```
`bucket` at ccn 5 outranks `curve` at ccn 9 because five commits touched it and one
touched `curve`. That is the whole point of weighting by churn. `spread` carries the `ok`
marker: already at or under its ceiling, listed anyway, and `next-item` would not hand it
out.
The list splits in two: **active** (files with commits in the window) and **dormant**
(zero churn, kept out of the queue but counted). Two rules reach under the
`worklist_floor`. A file whose churn weight sits in the top 10% is promoted down to ccn 3,
which is why `spread` appears above at ccn 4. And a function over its ceiling is admitted
whatever its ccn, so the floor can never hold back debt.
### The trusted baseline
Every `verify` measures the working tree against one earlier run, the **trusted
baseline**. `crapkit runs list` marks which one that is today.
**Which runs qualify.** A `coverage` run, or a `verify` that passed. A failed `verify`
never qualifies, and neither does a `partial` run (a lane failed, so some scope fell back
to `no-lane`) nor a `hook` override record, which carries no scored rows at all. In `runs
list`, `verdict=-` marks a run that produces no verdict rather than one that failed: only
`verify` renders a verdict. Four readers ask this one question and get this one answer: the
baseline pick here, `ratchet seed`, `prune`, and the tighten damping that compares a mark
against the same commit's previous run. A mark can no longer be signed off a run `verify`
refused.
**What advances it.** Any qualifying run. `coverage` writes one wherever HEAD is, so a
dashboard cron advances the baseline exactly as CI does. A passing `verify` advances it
and tightens the ratchet on the way.
**The taint rule.** A failed `verify` recorded findings against a tree. Until some
`verify` passes, runs made after that failure do not become the baseline: choosing one
would move the comparison point past the findings, the flagged function would stop
counting as touched, and nothing would look at it again. `verify` says which run it
refused and falls back to the newest run in front of the failure.
```
$ crapkit runs list
run 1 @ 88012a148f6 2026-08-23T09:27:46Z coverage verdict=- lanes=py baseline
run 2 @ 803bdde8556 2026-08-23T09:27:53Z verify verdict=FAILED lanes=py
run 3 @ 803bdde8556 2026-08-23T09:28:02Z coverage verdict=- lanes=py
$ crapkit verify
warning: run 3 is not the baseline: verify run 2 FAILED with 1 finding(s) and no passing verify has cleared it since — measuring against run 1 @ 88012a148f6 instead, so those findings stay visible. Fix them, or pass `--baseline 3` to accept the newer run deliberately.
verify FAILED @ d89068de7f3 vs baseline 88012a148f6 (2 changed files)
GATE crap 72.0 ccn 8 cov 0% calc/legacy.py:7 legacy_router( a , b , c , d , e ) -> decompose
findings: 1 committed / 0 dirty (uncommitted edits and untracked files)
```
Run 3 is a `coverage` run somebody took on the tree run 2 refused, and it scores the same
ccn-8 function. Without the rule it would have become the baseline, `legacy_router` would
have stopped being a touched function, and that gate line would never print again.
**The escape, twice.** Fix the findings and let a `verify` pass, which clears the taint
for good. Or accept the newer run on purpose with `verify --baseline 3`: an explicit id
bypasses the rule, and the run history records which run the verdict used. Nothing here
touches a repo that has never run `verify`: with no failure to protect, `coverage` alone
always advances the baseline.
**When the id you pass cannot serve.** A `--baseline ID` naming a real run that is not a
candidate says which run it is, why, and which ones can:
```
$ crapkit verify --baseline 3
crapkit: run 3 is an inventory run (no coverage was measured) and cannot serve as a baseline; trusted runs: 1, 2; pass `--baseline 2` for the newest
```
## Exit codes
| Code | Meaning |
|---|---|
| 0 | OK. For `verify` and `hook-precommit`: the gate passed. |
| 1 | **Overloaded.** Three unrelated things, listed below the table. |
| 2 | Usage error from argparse: unknown flag, missing positional. Raised before crapkit's own error handling. |
| 3 | Config error: `crapkit.toml` missing or unparseable, an unknown language or parser, a lane command the shell that runs it reads as a narrowed suite, a ratchet metr