# Investigate Before Editing

Diagnoses unclear failures with ranked hypotheses before any code is changed.

- Repository: https://github.com/JuliusBrussee/caveman (116680 stars)
- Category: Engineering
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add JuliusBrussee/caveman --skill investigate-first -g -a claude-code -y`
Codex: `npx skills add JuliusBrussee/caveman --skill investigate-first -g -a codex -y`
Cursor: `npx skills add JuliusBrussee/caveman --skill investigate-first -g -a cursor -y`
Gemini CLI: `npx skills add JuliusBrussee/caveman --skill investigate-first -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add JuliusBrussee/caveman`

## Description

Diagnose ambiguous failures before editing. Use for unknown causes, intermittent behavior, performance regressions, or investigations needing evidence-ranked hypotheses.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Investigate first

Gather evidence before changing product code.

- Separate observed symptom from inferred cause.
- Trace inputs, state transitions, ownership boundaries, and failure output.
- Rank hypotheses by evidence and cheap falsification value.
- Do not edit until one credible mechanism explains evidence.
- Stop exploration when evidence is sufficient to name cause or exact blocker.

Report cause and proof. Make no fix unless task authorizes implementation.