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QualityShell

Investigate

by testdouble

Investigate is a Quality skill for Claude Code, published by testdouble in han.

253 stars22 forkson testdouble/hanAdded 2026/09/02+9% in starsRepository updated 2026/09/01
View source on GitHubDownload repo ZIP
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Install in seconds
Install Investigate
Copy Investigate into your Claude Code skills folder. Run the command in your terminal, or review the source on GitHub before installing.
terminal
npx degit https://github.com/testdouble/han/tree/main/han-coding/skills/investigate ~/.claude/skills/investigate

Requires Node.js. Downloads this skill only — not the rest of the repository — into your Claude Code skills folder.

Without Node.js

git clone https://github.com/testdouble/han.git

Clones the whole repository, then copy the skill’s own directory into your skills folder yourself.

In this catalog

Source file
han-coding/skills/investigate/SKILL.md in testdouble/han
Installs to
~/.claude/skills/investigate
Collection
One of 25 skills cataloged from this repository
Category
Quality — 1418 skills

What Investigate does

Investigate traces software issues from symptoms back to root cause using evidence from code, logs, and tests. Use it when debugging bugs, failed integrations, or API behavior that needs a deep dive rather than a code review.

Investigate is cataloged under Quality on DirSkills. Investigate comes from a repository tagged claude, claude-code, claude-code-plugin, claude-skills and code-review.

Documentation

README

Project Context

  • CLAUDE.md: !find . -maxdepth 1 -name "CLAUDE.md" -type f
  • project-discovery.md: !find . -maxdepth 3 -name "project-discovery.md" -type f
  • personal config directory: !bash "${CLAUDE_PLUGIN_ROOT}/scripts/han-config-dir.sh" 2>/dev/null || echo "$HOME/.claude"
  • project .han/config.md: !cat .han/config.md 2>/dev/null || echo ""

This is the opening of the README. Read the full README on GitHub.

Frequently asked about Investigate

  • What else does testdouble publish alongside Investigate?

    Investigate is one of 25 skills that DirSkills catalogs from testdouble/han, the repository it ships in. Its siblings there include Architectural Analysis, Automated Test Planning and Code Overview. Each one is a separate skill with its own page in this directory, installs the same way Investigate does, and is maintained by testdouble in that same repository. The rest of the collection is listed on the testdouble/han page.

  • How does Investigate compare to other Quality skills?

    Investigate ranks #1285 by stars among the 1418 Quality skills in this catalog. The most-starred ones next to it are Benchmark, Benchmark Optimization Loop and API Design Patterns. DirSkills ranks by the star count of the repository each skill ships in, so that order reflects how popular those repositories are rather than any review of Investigate against them. Open each page to compare what they document and how they install.

More from testdouble/han

Investigate is one of 25 skills cataloged on DirSkills from testdouble/han.

See all 25 skills →
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Architectural Analysis

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Automated Test Planning

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Code Overview

Code Overview produces a progressive-disclosure summary of unfamiliar code or a pull request’s changes, explaining why it exists, what it does, and where to start. Use it to get oriented before working on or reviewing code; it writes only a scratch file and does not change the target.
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Code Review

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Code Walkthrough

Code Walkthrough walks a person through code changes one step at a time, starting at the entry point and following the flow that changed. It is used to learn, teach, or prepare to review existing code before extending it.
Quality
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