codeshell: Instructions file for Codex

AGENTS.md

codeshell AGENTS.md is an instructions file for Codex, OpenCode from cjhyy/codeshell. It costs 47 tokens per session, scanned A, original, MIT.

A repository instruction file that tells a coding agent how to work in the CodeShell project. It points the agent to CODESHELL.md for branch, build, test, style, and architecture rules.

In plain words
What is it for?
Use it when asking an agent to change this repository so it checks the required instructions first.
Why use it?
It gives the agent project-specific rules before it edits files, reducing work that conflicts with the repository’s workflow or design.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions AGENTS.md.

This is cjhyy/codeshell's own configuration. It tells Codex and OpenCode how to work on codeshell itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything codeshell configures →

Reuse

Borrowing it

Nothing to install: this file belongs to cjhyy/codeshell. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/cjhyy/codeshell/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/cjhyy/codeshell

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 codeshell AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/cjhyy/codeshell/agents-md/github.svg)](https://agentmods.dev/instructions/cjhyy/codeshell/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/cjhyy/codeshell/agents-md"><img src="https://agentmods.dev/badge/instructions/cjhyy/codeshell/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.

agentmods 80×15 button for codeshell AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/cjhyy/codeshell/agents-md"><img src="https://agentmods.dev/badge/instructions/cjhyy/codeshell/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 This file is loaded in full into every session.
When invoked 47 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00047 $0.00047
Opus 5.5 $0.00019 $0.00019
Sonnet 5.5 $0.00009 $0.00009
Haiku 4.5 $0.00005 $0.00005

Measured 6d ago against content hash 2980647020f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

codeshell 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 6d 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 · 6 lines

What it actually says

AGENTS.md

This repository uses CODESHELL.md as the primary assistant instruction file. Read it before editing for branch/worktree workflow, build, test, style, and architecture guidance.

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. 6d ago First seen · 6 lines · 47 tokens per session scan A 2980647020f0

Subscribe to this mod's changes

codeshell AGENTS.md is an instructions file published in the GitHub repository cjhyy/codeshell (65 stars, last pushed 2d ago), licensed MIT. It adds 47 tokens to every session, 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 2026-10-14.

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