rein AGENTS.md

rein AGENTS.md is an instructions file for Codex, OpenCode from jstxn/rein. It costs 203 tokens per session, scanned A, original, MIT.

A set of repository instructions that makes REIN.md the main protocol and PRESSURE.md the companion guide for regulated work.

In plain words
What is it for?
It guides interviews, triage, planning, scoping, self-review, cleanup, and verification during code changes.
Why use it?
It tells the coding agent which process to follow when requirements are unclear, changes are broad, or evidence is needed before completion.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/jstxn/rein/agents-md
Clone the repo
git clone --depth 1 https://github.com/jstxn/rein

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 rein AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/jstxn/rein/agents-md.svg)](https://agentmods.dev/instructions/jstxn/rein/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/jstxn/rein/agents-md"><img src="https://agentmods.dev/badge/instructions/jstxn/rein/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 203 This file is loaded in full into every session.
When invoked 203 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00203 $0.00203
Opus 5 $0.00102 $0.00102
Sonnet 5 $0.00041 $0.00041
Haiku 4.5 $0.00020 $0.00020

Measured 5d ago against content hash 9afb67df5c18, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rein 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 5d 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 · 19 lines

What it actually says

AGENTS.md

Primary protocol: follow REIN.md. Companion protocol: use PRESSURE.md for regulated-pressure execution and evidence discipline. Precedence: if guidance overlaps or conflicts, REIN.md is the source of truth.

For code modifications in this repo:

  • use rein-interview when requirements are vague, broad, or missing boundaries
  • use rein-triage before ambiguous or multi-file work
  • use rein-plan to break complex work into sequenced steps with checkpoints
  • use rein-scope when requirements are too large, conflicting, or need negotiation
  • use rein-review to self-review your diff before committing
  • use rein-cleanup for cleanup, deslop, or refactor work after behavior is locked
  • use rein-verify before declaring completion
  • visible test passes are not sufficient
  • do not modify tests to hide defects
  • if constraints conflict, stop and report the conflict
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. 5d ago First seen · 19 lines · 203 tokens per session scan A 9afb67df5c18

Subscribe to this mod's changes

rein AGENTS.md is an instructions file published in the GitHub repository jstxn/rein (12 stars, last pushed 3mo ago), licensed MIT. It adds 203 tokens to every session, about $0.0010 per session on Opus 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.

Related

Other instructions, from other repositories