# Anti Entropy Governance

Use when touching retiring old logic, collapsing duplicate owners, removing fallbacks...

- Repository: https://github.com/GanyuanRan/Aegis (1408 stars)
- Category: Engineering
- License: MIT
- Last updated: 2026-10-25
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add GanyuanRan/Aegis --skill anti-entropy-governance -g -a claude-code -y`
Codex: `npx skills add GanyuanRan/Aegis --skill anti-entropy-governance -g -a codex -y`
Cursor: `npx skills add GanyuanRan/Aegis --skill anti-entropy-governance -g -a cursor -y`
Gemini CLI: `npx skills add GanyuanRan/Aegis --skill anti-entropy-governance -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add GanyuanRan/Aegis`

## Description

Use when touching retiring old logic, collapsing duplicate owners, removing fallbacks, or schema/persistence/source-of-truth boundaries; identify opportunities automatically; destructive execution requires explicit confirmation.

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

# Anti-Entropy

## Overview

Use this skill when the task is not merely "change code" but "remove old paths
safely without growing entropy".

This skill chooses between:

- `delete-first` for internal code retirement
- `compat-exception` for proven external dependency boundaries
- `confirmation-first` for irreversible state or an external contract whose
  distributed consumers cannot be observed

It does not replace `brainstorming`, `writing-plans`,
`systematic-debugging`, or `verification-before-completion`. It is a narrow
governance owner for retirement, fallback collapse, duplicate-owner cleanup,
and deletion safety.

## When to Use

Use when any of these are true:

- old logic, duplicate owners, or stale fallbacks should be retired
- a candidate fix is "delete old path" vs "add another fallback"
- internal keyword / phrase / trigger logic is being replaced by structured logic
- a new canonical owner exists and the old owner may still carry real behavior
- a cleanup, migration, or deprecation task touches schema, persistence,
  source-of-truth, or external compatibility boundaries
- the task risks confusing code retirement with live data deletion

Do not use for:

- pure additive feature work with no retirement decision
- tiny wording edits
- simple status or read-only Q&A
- normal bug fixes that do not involve owner collapse, fallback cleanup, or
  deletion choice

## Auto-Compose Boundary

This skill should be composed by other owners. It should not become a new
global hot-path entry.

Prefer composition from:

- `brainstorming` for approach selection involving retirement or persistence risk
- `writing-plans` for plans that delete old paths or touch schema / migration /
  persistence
- `systematic-debugging` when the tempting fix is fallback growth or
  delete-vs-retain
- `verification-before-completion` for cleanup / retirement / compatibility /
  migration closeout

The rest: https://github.com/GanyuanRan/Aegis/blob/HEAD/skills/anti-entropy-governance/SKILL.md