plan42: Instructions file for Codex

AGENTS.md

plan42 AGENTS.md is an instructions file for Codex, OpenCode from sh1nj1/plan42. It costs 549 tokens per session, scanned A, original, no licence file.

A set of AGENTS.md rules for developing the plan42 project. AGENTS.md is a file that tells coding agents how to work in a codebase.

In plain words
What is it for?
It helps agents follow plan42’s development guide, find documentation, and apply the project’s working conventions.
Why use it?
It gives an agent the project’s development, documentation, language, and operating rules in one place.

Instructions file for CodexOpenCode

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

This is sh1nj1/plan42's own configuration. It tells Codex and OpenCode how to work on plan42 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 plan42 configures →

Reuse

Borrowing it

Nothing to install: this file belongs to sh1nj1/plan42. 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/sh1nj1/plan42/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/sh1nj1/plan42

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 plan42 AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/sh1nj1/plan42/agents-md/github.svg)](https://agentmods.dev/instructions/sh1nj1/plan42/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/sh1nj1/plan42/agents-md"><img src="https://agentmods.dev/badge/instructions/sh1nj1/plan42/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 plan42 AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/sh1nj1/plan42/agents-md"><img src="https://agentmods.dev/badge/instructions/sh1nj1/plan42/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 549 This file is loaded in full into every session.
When invoked 549 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 unknown 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 $0.00549 $0.00549
Opus 5.5 $0.00220 $0.00220
Sonnet 5.5 $0.00110 $0.00110
Haiku 4.5 $0.00055 $0.00055

Measured 1mo ago against content hash 1f10d4540b3d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

plan42 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 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.

AGENTS.md · 44 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 1mo ago First seen · 44 lines · 549 tokens per session scan A 1f10d4540b3d

Subscribe to this mod's changes

plan42 AGENTS.md is an instructions file published in the GitHub repository sh1nj1/plan42 (13 stars, last pushed 3d ago), with no licence file. It adds 549 tokens to every session, about $0.0022 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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