keep-the-why: Instructions file for Codex

AGENTS.md

keep-the-why AGENTS.md is an instructions file for Codex, OpenCode from oliver-zehentleitner/keep-the-why. It costs 239 tokens per session, scanned A, original, MIT.

Project instructions for Keep the Why, a system that stores the reasoning behind code and project decisions. They explain which context files to read and how to format selected documentation changes.

In plain words
What is it for?
Use them before making substantial changes, when reviewing project context, or when updating the changelog and decision records.
Why use it?
They help a coding agent preserve existing decisions instead of accidentally undoing them, while keeping changelog and context updates consistent.

Instructions file for CodexOpenCode

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

This is oliver-zehentleitner/keep-the-why's own configuration. It tells Codex and OpenCode how to work on keep-the-why 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 keep-the-why configures →

Reuse

Borrowing it

Nothing to install: this file belongs to oliver-zehentleitner/keep-the-why. 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/oliver-zehentleitner/keep-the-why/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/oliver-zehentleitner/keep-the-why

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.

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README.md
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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.

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Your own site · 80×15
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Per session 239 This file is loaded in full into every session.
When invoked 239 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 $0.00239 $0.00239
Opus 5 $0.00120 $0.00120
Sonnet 5 $0.00048 $0.00048
Haiku 4.5 $0.00024 $0.00024

Measured 6d ago against content hash 89b7d3900db8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

keep-the-why 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 · 19 lines

What it actually says

AGENTS.md

This project uses Keep the Why (itself) to preserve the reasoning behind its own code.

  • Usage docs: see docs/ (or https://keepthewhy.com)
  • Why things are the way they are: see context/index.md
  • If AGENTS.local.md exists in this checkout, read that too — personal/local notes, not committed.

Read context/index.md before making non-trivial changes — naming, docs tooling, and repo structure have already been argued through once; check there before re-litigating or accidentally reverting a decision.

Keep the Why's config for this project migrated to .keep-the-why on 2026-09-01 — requires skill version 0.10.0 or later to read it.

Working conventions (no why needed, just follow these)

  • CHANGELOG.md: one ### Added / ### Changed / ### Fixed heading per category under [Unreleased] — reuse an existing one instead of opening a new one for the same category. Entries within a category, alphabetically ordered by first word, not insertion order.
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 Changed · -5 lines · -16 tokens per session 89b7d3900db8
  2. 10d ago First seen · 24 lines · 255 tokens per session scan A 34389f2b926a

Subscribe to this mod's changes

keep-the-why AGENTS.md is an instructions file published in the GitHub repository oliver-zehentleitner/keep-the-why (155 stars, last pushed today), licensed MIT. It adds 239 tokens to every session, about $0.0012 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.

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