Aegis AGENTS.md

Aegis AGENTS.md is an instructions file for Codex, OpenCode from GanyuanRan/Aegis. It costs 1,235 tokens per session, scanned A, original, MIT.

Repository instructions for AI coding agents working in the Aegis codebase. They explain what the repository is, which documents have authority, and what agents must read before changing code.

In plain words
What is it for?
Guiding agents through Aegis repository tasks, including choosing the right documentation, following instruction priorities, and respecting project boundaries.
Why use it?
They reduce conflicting interpretations and help agents make small, verifiable changes that fit the project's rules.

Instructions file for CodexOpenCode

About the project

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.

GanyuanRan/Aegis · 1,167 stars · on GitHub

Install

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.

agentmods
npx agentmods add instructions/ganyuanran/aegis/agents-md
Clone the repo
git clone --depth 1 https://github.com/GanyuanRan/Aegis

Made for: Codex, OpenCode.

Wrote 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.

agentmods badge for Aegis AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/ganyuanran/aegis/agents-md.svg)](https://agentmods.dev/instructions/ganyuanran/aegis/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/ganyuanran/aegis/agents-md"><img src="https://agentmods.dev/badge/instructions/ganyuanran/aegis/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,235 This file is loaded in full into every session.
When invoked 1,235 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.01235 $0.01235
Opus 5 $0.00617 $0.00617
Sonnet 5 $0.00247 $0.00247
Haiku 4.5 $0.00123 $0.00123

Measured 5d ago against content hash 892cb64cdc86, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Aegis AGENTS.md 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 5d 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.

AGENTS.md · 185 lines

How it starts

The opening of the file, as written. The whole thing — 185 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Aegis Repository Agent Guide

Status: Approved

1. Purpose

This file is the public repository guide for AI coding agents working in the Aegis repository.

It defines:

  • what this repository is and is not
  • which authority docs to read before changing behavior
  • how to keep changes small, verifiable, and public-safe
  • which boundaries must not drift while improving Aegis

It does not replace:

  • docs/current/README.md for the current authority map
  • approved ADRs in docs/adr/
  • task-specific baseline docs in docs/current/
  • installed Aegis skills and workflows
  • host-specific installation docs such as docs/README.codex.md, docs/README.opencode.md, docs/README.claude-code.md, docs/README.codebuddy.md, docs/README.deepseek-tui.md, and docs/README.trae.md

2. Authority Order

When instructions conflict, use this order:

  1. The user's current explicit instruction
  2. this root AGENTS.md
  3. docs/current/README.md
  4. approved ADRs in docs/adr/
  5. task-specific approved docs in docs/current/
  6. host-specific docs and tests
  7. installed Aegis skills and workflow guidance

If the authority source is unclear, state the gap and choose the smallest verifiable path.

3. Baseline Read-Set

For non-trivial work, read these first:

  1. docs/current/README.md
  2. docs/adr/ADR-0001-aegis-method-pack-is-not-runtime-core.md
  3. the smallest task-relevant docs/current/*.md

Add these when relevant:

  • prompt hygiene / context injection: docs/current/AEGIS_PROMPT_HYGIENE_AND_INJECTION_BOUNDARY.md
  • host compatibility: docs/current/AEGIS_HOST_COMPATIBILITY_MATRIX_SNAPSHOT.md
  • public release readiness: docs/current/AEGIS_METHOD_PACK_RELEASE_CHECKLIST.md
  • Claude Code-specific work: CLAUDE.md and docs/README.claude-code.md

4. Repository Positioning

The current product boundary is:

Aegis Method Pack (runtime-ready)

This repository owns:

  • skills
  • initial instructions
  • workflow discipline
  • host-installable method-pack distribution
  • runtime-ready drafts, hints, and projections

Read the full file on GitHub · 185 lines

Changes

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.

  1. 5d ago First seen · 185 lines · 1,235 tokens per session scan A 892cb64cdc86

Subscribe to this mod's changes

Aegis AGENTS.md is an instructions file published in the GitHub repository GanyuanRan/Aegis (1,167 stars, last pushed yesterday), licensed MIT. It adds 1,235 tokens to every session, about $0.0062 per session on Opus 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.