playlab42: Instructions file for Codex

AGENTS.md

playlab42 AGENTS.md is an instructions file for Codex, OpenCode from z4ppy/playlab42. It costs 4,691 tokens per session, scanned A, original, no licence file.

Project-specific AGENTS.md instructions for playlab42, a project that teaches concepts about AI agents. They describe the project, its architecture, key concepts, and educational objective.

In plain words
What is it for?
Use them when asking an agent to inspect, change, or explain the playlab42 codebase.
Why use it?
They give coding agents the context and rules needed to work consistently in that repository. Without them, an agent may miss the project’s structure or teaching purpose.

Instructions file for CodexOpenCode

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

This is z4ppy/playlab42's own configuration. It tells Codex and OpenCode how to work on playlab42 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 playlab42 configures →

Reuse

Borrowing it

Nothing to install: this file belongs to z4ppy/playlab42. 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/z4ppy/playlab42/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/z4ppy/playlab42

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 playlab42 AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/z4ppy/playlab42/agents-md/github.svg)](https://agentmods.dev/instructions/z4ppy/playlab42/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/z4ppy/playlab42/agents-md"><img src="https://agentmods.dev/badge/instructions/z4ppy/playlab42/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 playlab42 AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/z4ppy/playlab42/agents-md"><img src="https://agentmods.dev/badge/instructions/z4ppy/playlab42/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 4,691 This file is loaded in full into every session.
When invoked 4,691 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 $0.04691 $0.04691
Opus 5.5 $0.01876 $0.01876
Sonnet 5.5 $0.00938 $0.00938
Haiku 4.5 $0.00469 $0.00469

Measured 1mo ago against content hash c8f353e6d2f6, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

playlab42 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 · 431 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 Changed · +28 lines · +488 tokens per session c8f353e6d2f6
  2. 1mo ago Changed · +26 lines · +619 tokens per session 38920068cb67
  3. 1mo ago Changed · -2 tokens per session dc59a27a6162
  4. 2mo ago First seen · 377 lines · 3,586 tokens per session scan A 2bb105932b3e

Subscribe to this mod's changes

playlab42 AGENTS.md is an instructions file published in the GitHub repository z4ppy/playlab42 (2 stars, last pushed 11d ago), with no licence file. It adds 4,691 tokens to every session, about $0.0188 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 2026-08-31.

Related

playlab42 AGENTS.md compared with instructions from other repositories

playlab42 AGENTS.md next to 6 instructions from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
playlab42 AGENTS.mdz4ppy/playlab42Instructions file211d agononeA4,691Codex, OpenCode
plan-forge database.instructions.mdsrnichols/plan-forgeInstructions file62d agoMITA1,890GitHub Copilot
vscode buildNext.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA9,719GitHub Copilot
next.js AGENTS.mdvercel/next.jsInstructions file143ktodayMITA7,461Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchainInstructions file149kyesterdayMITA4,680Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA5,516GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA3,093GitHub Copilot