bug-investigation

bug-investigation is a skill for Claude Code from lklimek/claudius. It costs 49 tokens per session (669 once invoked), scanned A, original, GPL-3.0.

A bug-investigation workflow for diagnosing reported failures and tracing symptoms back to their root cause.

In plain words
What is it for?
Use it for bug reports, failures, root-cause analysis, and evidence-based explanations of unexpected behavior.
Why use it?
It provides a structured way to investigate unexpected behavior before deciding whether something is or is not a bug.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the claudius plugin — 30 skills, 8 agents, 2 hooks shipped together

Good fit Use it for bug reports, failures, root-cause analysis, and evidence-based explanations of unexpected behavior.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/lklimek/claudius/bug-investigation
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 lklimek/claudius --skill bug-investigation
Clone the repo
git clone --depth 1 https://github.com/lklimek/claudius

Made for: Claude Code.

Or install claudius, the plugin that ships this one along with the rest of its 30 skills, 8 agents, 2 hooks.

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.

agentmods badge for bug-investigation

README.md
[![agentmods](https://agentmods.dev/badge/skills/lklimek/claudius/bug-investigation/github.svg)](https://agentmods.dev/skills/lklimek/claudius/bug-investigation)
Your own site
<a href="https://agentmods.dev/skills/lklimek/claudius/bug-investigation"><img src="https://agentmods.dev/badge/skills/lklimek/claudius/bug-investigation/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.

agentmods 80×15 button for bug-investigation

Your own site · 80×15
<a href="https://agentmods.dev/skills/lklimek/claudius/bug-investigation"><img src="https://agentmods.dev/badge/skills/lklimek/claudius/bug-investigation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 669 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 unknown 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.00669
Opus 5 $0.00024 $0.00334
Sonnet 5 $0.00010 $0.00134
Haiku 4.5 $0.00005 $0.00067

Measured 9d ago against content hash b94d3fbe30d4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

bug-investigation 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.

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.

skills/bug-investigation/SKILL.md · 34 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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.

  1. 9d ago First seen · 34 lines · 49 tokens per session scan A b94d3fbe30d4

Subscribe to this mod's changes

bug-investigation is a skill published in the GitHub repository lklimek/claudius (1 stars, last pushed today), licensed GPL-3.0. It adds 49 tokens to every session and 669 once invoked, about $0.0002 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.

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