Mole Bug Patterns
tw93/Mole
A catalog of recurring bug shapes in the Mole Mac cleaner, used to review safety-sensitive diffs for deletion safety, unbounded commands, shell traps and weak tests.
Audit for arithmetic and boundary bugs (overflow, off-by-one, drift)
Apache-2.0Auto-check passed
Install Audit Arithmetic
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install ben-manes/caffeine audit-arithmetic --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/audit-arithmetic .claude/skills/audit-arithmetic && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .claude/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmeticType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install ben-manes/caffeine audit-arithmetic --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/audit-arithmetic .agents/skills/audit-arithmetic && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .agents/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install ben-manes/caffeine audit-arithmetic --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/audit-arithmetic .cursor/skills/audit-arithmetic && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .cursor/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/ben-manes/caffeine.git --path .claude/skills/audit-arithmetic--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install ben-manes/caffeine audit-arithmetic --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/audit-arithmetic .gemini/skills/audit-arithmetic && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .gemini/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install ben-manes/caffeine audit-arithmeticInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/audit-arithmetic .github/skills/audit-arithmetic && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .github/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add ben-manes/caffeine --skill audit-arithmetic -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install ben-manes/caffeine audit-arithmetic --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/ben-manes/caffeine.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/audit-arithmetic .opencode/skills/audit-arithmetic && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "audit-arithmetic" agent skill from https://github.com/ben-manes/caffeine/tree/master/.claude/skills/audit-arithmetic into .opencode/skills/audit-arithmetic/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "audit-arithmetic", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
audit-arithmetic- GitHub stars
- 18k
- Token cost
- ~437 tokens
- SKILL.md length
- 192 words
- Files
- 1
- Skills in repo
- 33
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
Audit for arithmetic and boundary bugs (overflow, off-by-one, drift)
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
Audit Arithmetic is an agent skill from ben-manes/caffeine. Audit for arithmetic and boundary bugs (overflow, off-by-one, drift)
Its SKILL.md is about 440 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: A high performance caching library for Java. The licence is Apache-2.0.
Example prompts
- “/audit-arithmetic”
What it can do on your machine
Read from SKILL.md and the folder at commit e972fb0. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Audit Arithmetic loads about 437 tokens when it runs. Until then it costs about 21 tokens; SKILL.md has 192 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from ben-manes/caffeine at commit e972fb0, republished under its Apache-2.0 licence (© ben-manes). 192 words, ~437 tokens.
Download SKILL.mdSave it as
.claude/skills/audit-arithmetic/SKILL.md (or your agent's skills folder).- name
- audit-arithmetic
- description
- Audit for arithmetic and boundary bugs (overflow, off-by-one, drift)
- context
- fork
- agent
- auditor
- disable-model-invocation
- true
Assume there is at least one arithmetic or boundary bug in this code.
Audit for:
- Off-by-one errors
- Incorrect inequality direction (< vs <=, > vs >=)
- Overflow / underflow (int, long, specifically nanoTime arithmetic)
- Implicit narrowing or widening conversion
- Incorrect rounding or truncation
- Sign errors
- Sentinel value collisions (can a valid value equal a sentinel?)
- Counter drift (can a counter diverge from the quantity it tracks over a long-running cache?)
- Timer wheel bucket arithmetic (modular arithmetic, wrap-around)
- Frequency sketch counter saturation and reset arithmetic
- Hill climber / adaptive sizing: window vs main partition adjustment; the density and
probe-verdict log-ratios (
ln((x+ε)/(y+ε))), the probation-capacity denominator (max(1, maximum − windowMaximum − mainProtectedMaximum)), the saturated4·maximumsample period, and the stride/commitment rung tables (percentage calculations, rounding, overshoot, oscillation) - FrequencySketch table size calculation (ensureCapacity rounding to power of two, interaction with maximumSize)
- Weight delta computation in UpdateTask (sign conventions, can intermediate sums overflow when weights are near Integer.MAX_VALUE?)
For each suspected issue:
- Provide a concrete input (specific key, value, weight, time values)
- Show step-by-step evaluation through the code
- Show expected vs actual behavior
- If it requires billions of operations, state the count needed
Ignore style and performance. Only report high-confidence defects supported by evaluation traces.
© ben-manes, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .claude/skills/audit-arithmetic of ben-manes/caffeine.
Open the folder on GitHubat commit e972fb0
Compare with similar skills
Audit Arithmetic next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Audit Arithmetic this skillben-manes/caffeine | 18k | — | ~437 | Automated safety check: Pass | Apache-2.0 | |
| Mole Bug Patternstw93/Mole | 70k | — | ~2k | Automated safety check: Pass | GPL-3.0 | |
| Add Bugremotion-dev/remotion | 62k | — | ~215 | Automated safety check: Pass | Custom licence | |
| Bugccch1mneyyy/dsh-TUI | 4.2k | — | ~342 | Automated safety check: Pass | MIT | |
| Bug Bountysickn33/agentic-awesome-skills | 47k | 1 repos | ~5k | Automated safety check: Notes | MIT | |
| Add Webcodecs Bugremotion-dev/remotion | 62k | — | ~411 | Automated safety check: Pass | Custom licence |
Similar skills
- Official
Add Bug
remotion-dev/remotion
Add a new Remotion bug entry to packages/bugs/api/[v].ts. An agent skill from remotion-dev/remotion.
Bug
ccch1mneyyy/dsh-TUI
Turn a reported defect into an actionable bug report or issue draft.
Bug Bounty
sickn33/agentic-awesome-skills
Complete bug bounty workflow
- Official
Add Webcodecs Bug
remotion-dev/remotion
Add a browser WebCodecs bug to the Remotion Mediabunny WebCodecs bugs docs page.
DeFi Smart Contract Bug Classes
tradecatlabs/vibe-coding-cn
Reference for ten classes of DeFi smart contract bugs, each with root cause, vulnerable code, fix, grep patterns and paid examples, for audits and bug bounty reviews.
More from ben-manes/caffeine
All 33 skills in this repoCaffeine Cache Optimization Experiments
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Runs controlled JMH experiments on the Caffeine cache to find shared contention and hot-path waste, then reviews correctness and returns a reviewable patch.
Git History Bug Audit
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Audits a module by walking its git history commit by commit, tracking unresolved issues forward, and reporting the ones that survive to HEAD as findings.
Adversarial Codebase Audit
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Runs a hostile review of the Caffeine Java caching library with parallel subagents that get no design docs, then challenges and consolidates their findings.
Caffeine Performance Audit
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Audits the Caffeine cache source for hot-path costs such as allocations, contention and memory layout, reporting only findings tied to specific lines.
Audit Sibling Divergence
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Compares code paths that should behave the same, such as sync and async cache methods, and requires a concrete scenario where the two observably disagree.
Climber Step Minimization
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Prices each step of the window climber algorithm by disabling it in turn, to find steps that no longer earn their keep and branches that no longer fire.
Questions about Audit Arithmetic
What does Audit Arithmetic do?
Audit for arithmetic and boundary bugs (overflow, off-by-one, drift). Audit Arithmetic is an agent skill from ben-manes/caffeine.
How do I install Audit Arithmetic in Claude Code?
Run `npx skills add ben-manes/caffeine --skill audit-arithmetic -a claude-code`. Or copy the skill folder (.claude/skills/audit-arithmetic in ben-manes/caffeine) into .claude/skills/audit-arithmetic in your project. Claude Code loads it when a task matches its description.
How do I install Audit Arithmetic in Codex?
Run `npx skills add ben-manes/caffeine --skill audit-arithmetic -a codex`. Or copy the skill folder (.claude/skills/audit-arithmetic in ben-manes/caffeine) into .agents/skills/audit-arithmetic in your project. Codex loads it when a task matches its description.
Can I use Audit Arithmetic in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add ben-manes/caffeine --skill audit-arithmetic -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/audit-arithmetic, .gemini/skills/audit-arithmetic, .github/skills/audit-arithmetic and .opencode/skills/audit-arithmetic in your project.
What does Audit Arithmetic need to run?
SKILL.md names no scripts, command-line tools or credentials: Audit Arithmetic is instructions for the agent only.
Does Audit Arithmetic access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Audit Arithmetic safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Audit Arithmetic use?
Audit Arithmetic is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Audit Arithmetic use?
About 437 tokens (SKILL.md is roughly 1.7k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Audit Arithmetic?
Skills that share tags, products or a category with Audit Arithmetic: Mole Bug Patterns (tw93/Mole, 70k stars), Add Bug (remotion-dev/remotion, 62k stars), Bug (ccch1mneyyy/dsh-TUI, 4.2k stars) and Bug Bounty (sickn33/agentic-awesome-skills, 47k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Audit Arithmetic?
ben-manes (a GitHub user) maintains it in ben-manes/caffeine, which has 17,880 GitHub stars. The repository holds 33 skills in this directory. The repository was last updated on October 6, 2026.
Source: ben-manes/caffeine on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.