Aegis is a method pack that guides coding agents to inspect a project's baseline, make bounded changes, and verify their work with fresh evidence. It is for people using coding-agent hosts who want fewer unverified changes and less unnecessary process. The catalogue add-ons implement this method through skills, instructions, commands, a hook, and a plugin.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add GanyuanRan/Aegis --skill anti-entropy-governancegit clone --depth 1 https://github.com/GanyuanRan/AegisWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ganyuanran/aegis/anti-entropy-governance)<a href="https://agentmods.dev/skills/ganyuanran/aegis/anti-entropy-governance"><img src="https://agentmods.dev/badge/skills/ganyuanran/aegis/anti-entropy-governance/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ganyuanran/aegis/anti-entropy-governance"><img src="https://agentmods.dev/badge/skills/ganyuanran/aegis/anti-entropy-governance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00042 | $0.02541 |
| Opus 5.5 | $0.00017 | $0.01016 |
| Sonnet 5.5 | $0.00008 | $0.00508 |
| Haiku 4.5 | $0.00004 | $0.00254 |
Grade A, and why
anti-entropy-governance scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 364 lines — stays where its author put it; the contents beside it link to each section on GitHub.
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-firstfor internal code retirementcompat-exceptionfor proven external dependency boundariesconfirmation-firstfor 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:
brainstormingfor approach selection involving retirement or persistence riskwriting-plansfor plans that delete old paths or touch schema / migration / persistencesystematic-debuggingwhen the tempting fix is fallback growth or delete-vs-retainverification-before-completionfor cleanup / retirement / compatibility / migration closeout
Load automatically when the task touches owner collapse, fallback removal, or schema/persistence/source-of-truth boundaries. Automatic loading identifies and advises only; destructive execution still requires explicit scoped user confirmation.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +8 lines 1d2f4d7c2c0c
- 1mo ago Changed · +4 lines 73d648bcc909
- 1mo ago Changed · +13 lines 36dd51150796
- 1mo ago First seen · 339 lines · 42 tokens per session scan A 8579aae931fa
anti-entropy-governance is a skill published in the GitHub repository GanyuanRan/Aegis (1,387 stars, last pushed 2d ago), licensed MIT. It adds 42 tokens to every session and 2,541 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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