# Principle Fix Root Causes

> Reproduce a failure, trace the first incorrect value or state, fix that origin, and prove the nearby class of symptoms cannot return through another path.

- Skill: `njs14/principle-fix-root-causes` (Agent Skill)
- Install (CLI): `npx skillmds@latest add njs14/principle-fix-root-causes`
- Raw SKILL.md: https://api.skillmd.com/api/skills/njs14/principle-fix-root-causes/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: njs14 (https://skillmd.com/u/njs14)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/njs14/principle-fix-root-causes

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# Fix the cause

Treat the request text that activated this skill as the failure to diagnose.

Apply [fix root causes](../pkstack-principles/references/catalog.md#fix-root-causes). Reproduce first, follow
the state backward to where it becomes wrong, and instrument uncertainty instead of guessing.
Inspect persisted state for restart-only bugs. Reject a guard that merely hides the symptom. Return
the cause, the smallest causal fix, and the regression evidence.