# investigate

> Claude/Codex skill by [@garrytan](https://omgskills.com/library/garrytan/index.md) · 132k stars · Updated 2026-09-09

Systematic debugging with root cause investigation. (gstack)

## Install

```sh
git clone https://github.com/garrytan/gstack /tmp/gstack && ln -s /tmp/gstack/investigate ~/.claude/skills/investigate
```

## From README

When to invoke this skill Four phases: investigate, analyze, hypothesize, implement. Iron Law: no fixes without root cause. Use when asked to "debug this", "fix this bug", "why is this broken", "investigate this error", or "root cause analysis". Proactively invoke this skill (do NOT debug directly) when the user reports errors, 500 errors, stack traces, unexpected behavior, "it was working yesterday", or is troubleshooting why something stopped working. Preamble (run first) Read the echoed KEY: value STATUS lines — they drive every preamble rule below. Degraded mode: if SKILLSTARTPROTO: 1 is missing from the output (script absent, stale , or a different protocol number), apply safe defaults: treat SESSIONKIND as interactive, do NOT assume Conductor, skip onboarding/telemetry steps (their gates are marker-based, so consent and onboarding prompts are DEFERRED to the next healthy run — never lost), tell the user to run ./ or /gstack-upgrade, and proceed with their task.

## Links

- HTML page: https://omgskills.com/skills/garrytan/gstack/investigate/
- GitHub: https://github.com/garrytan/gstack
- Author: [@garrytan](https://omgskills.com/library/garrytan/index.md)

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