GroundRules: Instructions file for Codex

AGENTS.md

GroundRules AGENTS.md is an instructions file for Codex, OpenCode from chama-x/GroundRules. It costs 75 tokens per session, scanned A, original, MIT.

A set of project instructions that tells an coding agent which guardrail files to read before changing a codebase.

In plain words
What is it for?
Use it when working in a codebase that has identity and grounding documents under .agents/rules/.
Why use it?
It helps the agent understand the project's rules, boundaries, tools, and working practices before taking action.

Instructions file for CodexOpenCode

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

This is chama-x/GroundRules's own configuration. It tells Codex and OpenCode how to work on GroundRules 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 GroundRules configures →

Reuse

Borrowing it

Nothing to install: this file belongs to chama-x/GroundRules. 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/chama-x/GroundRules/master/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/chama-x/GroundRules

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 GroundRules AGENTS.md

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

Your own site · 80×15
<a href="https://agentmods.dev/instructions/chama-x/groundrules/agents-md"><img src="https://agentmods.dev/badge/instructions/chama-x/groundrules/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 75 This file is loaded in full into every session.
When invoked 75 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 $0.00075 $0.00075
Opus 5.5 $0.00030 $0.00030
Sonnet 5.5 $0.00015 $0.00015
Haiku 4.5 $0.00007 $0.00007

Measured 1mo ago against content hash ea4afadbbece, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

GroundRules 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 · 5 lines

What it actually says

Agent Context Router

Before taking any action on this codebase, read the following guardrail files:

  1. .agents/rules/IDENTITY.md — Project stack, test command, and non-negotiable boundaries ("What We Don't Do").
  2. .agents/rules/GROUNDING.md — Cognitive protocol, epistemic security, and ambiguity resolution rules.
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 · 5 lines · 75 tokens per session scan A ea4afadbbece

Subscribe to this mod's changes

GroundRules AGENTS.md is an instructions file published in the GitHub repository chama-x/GroundRules (5 stars, last pushed 2mo ago), licensed MIT. It adds 75 tokens to every session, about $0.0003 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 2026-09-03.

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