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.
Borrowing it
Nothing to install: this file belongs to GanyuanRan/Aegis. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/GanyuanRan/Aegis/main/AGENTS.mdgit 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/instructions/ganyuanran/aegis/agents-md)<a href="https://agentmods.dev/instructions/ganyuanran/aegis/agents-md"><img src="https://agentmods.dev/badge/instructions/ganyuanran/aegis/agents-md/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/instructions/ganyuanran/aegis/agents-md"><img src="https://agentmods.dev/badge/instructions/ganyuanran/aegis/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.01342 | $0.01342 |
| Opus 5.5 | $0.00537 | $0.00537 |
| Sonnet 5.5 | $0.00268 | $0.00268 |
| Haiku 4.5 | $0.00134 | $0.00134 |
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 13d 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 — 194 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.mdfor 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, anddocs/README.trae.md
2. Authority Order
When instructions conflict, use this order:
- The user's current explicit instruction
- this root
AGENTS.md docs/current/README.md- approved ADRs in
docs/adr/ - task-specific approved docs in
docs/current/ - host-specific docs and tests
- 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:
docs/current/README.mddocs/adr/ADR-0001-aegis-method-pack-is-not-runtime-core.md- the task-to-owner row in
docs/current/README.md, then only the relevant section of itsdocs/current/*.mdowner
For tradeoffs about scope, repair, or completion, use the Outcome Principles
in docs/current/AEGIS_PROCESS_BASELINE.md §2.
The index is navigation, not a requirement to read every baseline. Use headings or bounded excerpts, reuse still-current context, and expand only for affected dependencies, contradictions, or missing evidence. Procedure details belong to the active skill; quality acceptance belongs to the workflow-quality baseline.
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.mdanddocs/README.claude-code.md
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.
- 13d ago Changed · +9 lines · +107 tokens per session d051cf463ae5
- 1mo ago First seen · 185 lines · 1,235 tokens per session scan A 892cb64cdc86
Aegis AGENTS.md is an instructions file published in the GitHub repository GanyuanRan/Aegis (1,383 stars, last pushed 4d ago), licensed MIT. It adds 1,342 tokens to every session, about $0.0054 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.