A code-quality loop that calculates a CRAP score for each function using complexity and test coverage. Test coverage is the share of code exercised by automated tests.

Use it only when explicitly requested to score functions, add tests first, split complex code, and repeat the measurement.

It identifies functions that are both complicated and poorly tested, then guides improvements until they fall below a chosen threshold.

crap-score — Skill for Codex by pktikkani

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add pktikkani/agent-skills --skill crap-score

Clone the repo

git clone --depth 1 https://github.com/pktikkani/agent-skills

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/pktikkani/agent-skills/crap-score/github.svg)](https://agentmods.dev/skills/pktikkani/agent-skills/crap-score)

Your own site

<a href="https://agentmods.dev/skills/pktikkani/agent-skills/crap-score"><img src="https://agentmods.dev/badge/skills/pktikkani/agent-skills/crap-score/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/pktikkani/agent-skills/crap-score"><img src="https://agentmods.dev/badge/skills/pktikkani/agent-skills/crap-score.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,036 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00079	$0.01036
Opus 5	$0.00039	$0.00518
Sonnet 5	$0.00016	$0.00207
Haiku 4.5	$0.00008	$0.00104

Measured 9d ago against content hash 84c6b3876f59, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

crap-score scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/crap_py.py, scripts/crap_ts.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

claude/skills/crap-score/SKILL.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CRAP score loop

Goal: every function's CRAP below threshold (default 8; stretch target 6). CRAP(m) = CC² × (1 − coverage)³ + CC — high complexity is forgivable only if well covered; uncovered complexity is not.

Detect stack from repo markers and produce per-function scores:

Python (pyproject.toml/requirements.txt): needs radon + coverage.

radon cc -j <src> > /tmp/radon.json
coverage run -m pytest -q && coverage json -o /tmp/coverage.json
python ~/.claude/skills/crap-score/scripts/crap_py.py /tmp/radon.json /tmp/coverage.json --threshold 8

Exit 1 = functions still over threshold (loop gate).

Go (go.mod): gocyclo -over 0 . for CC + go test -coverprofile=c.out ./... then go tool cover -func=c.out; join per function and compute CRAP yourself.

TS/Node (package.json): needs eslint + c8 (via npx --yes).

npx --yes eslint <src> -f json --rule '{"complexity":["warn",0]}' > /tmp/eslint.json
npx --yes c8 --reporter=json <test cmd>   # writes coverage/coverage-final.json
python ~/.claude/skills/crap-score/scripts/crap_ts.py /tmp/eslint.json coverage/coverage-final.json --threshold 8

Exit 1 = functions still over threshold (loop gate).

Report the baseline: worst 10 functions with file:line, CC, coverage, CRAP.
Loop — one function at a time, worst first (Bob's order): a. Cover first: if coverage is low, write characterization tests until the function's lines are covered. Never refactor uncovered code. b. Split second: only if CC alone keeps CRAP over threshold, extract smaller well-named functions (few args), keeping tests green. c. Re-run the scorer; confirm the number dropped and nothing else regressed.
Stop when the scorer exits 0. Write before/after table + changes to a file; reply with the path and the headline numbers.

Constraints: no behavior changes during refactors (tests must stay green); simplest split that clears the threshold, nothing speculative.

Read the full file on GitHub · 73 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

9d ago First seen · 73 lines · 79 tokens per session scan A 84c6b3876f59

Subscribe to this mod's changes

crap-score is a skill published in the GitHub repository pktikkani/agent-skills (2 stars, last pushed 2d ago), licensed MIT. It adds 79 tokens to every session and 1,036 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Testing

research-engineer

An uncompromising Academic Research Engineer. Operates with absolute scientific rigor, objective criticism, and zero flair. Focuses on theoretical correctness, formal verification, and optimal implementation across any required technology.

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apache/tika · 50 tokens

neuron-evaluation-engineer

Create and run AI evaluations with datasets, assertions, and output drivers in Neuron AI. Use this skill whenever the user mentions evaluation, testing AI systems, creating evaluators, dataset-driven testing, assertion-based validation, or wants to measure AI system performance. Also trigger for tasks involving…

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crap-score