heading-os: Instructions file for Claude Code

AGENTS.md

heading-os AGENTS.md is an instructions file for Claude Code, Codex, OpenCode from mishahanin/heading-os. It costs 3,594 tokens per session, scanned A, original, Apache-2.0.

A repository instruction file for HEADING OS, an operations engine that helps an AI executive assistant work across sessions. It covers the project’s purpose, setup, tests, and separation of code from private data.

In plain words
What is it for?
Use it when setting up the project, running tests, or changing its engine and private-data boundaries.
Why use it?
It helps coding agents understand how to work in the repository and prevents private contacts, credentials, and other operator data from being placed in the public codebase.

Instructions file for Claude CodeCodexOpenCode

Written for Claude Code and Codex and OpenCode: ${CLAUDE_PROJECT_DIR} variable, but also the file is AGENTS.md. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions Claude Code.

This is mishahanin/heading-os's own configuration. It tells Claude Code, Codex and OpenCode how to work on heading-os 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 heading-os configures →

Reuse

Borrowing it

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

Made for: Claude Code, 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 heading-os AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/mishahanin/heading-os/agents-md.svg)](https://agentmods.dev/instructions/mishahanin/heading-os/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/mishahanin/heading-os/agents-md"><img src="https://agentmods.dev/badge/instructions/mishahanin/heading-os/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 3,594 This file is loaded in full into every session.
When invoked 3,594 The same file — it is already loaded in full.
Security scan A 1 finding. 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 $0.03594 $0.03594
Opus 5 $0.01797 $0.01797
Sonnet 5 $0.00719 $0.00719
Haiku 4.5 $0.00359 $0.00359

Measured today against content hash 1559969db404, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

heading-os AGENTS.md scanned grade A with 1 finding 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 today.

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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

`subprocess(..., shell=True)` / `os.system()`, no `yaml.load()` without
AGENTS.md · 258 lines

How it starts

The opening of the file, as written. The whole thing — 258 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Instructions for coding agents (Codex, Cursor, and any AGENTS.md-aware tool) working in this repository. Claude Code agents should read CLAUDE.md instead (or in addition) — it is the Claude-Code-specific superset of what is here, carrying the always-on rules under .claude/rules/ that this file does not duplicate.

No AGENTS.md existed in this repository before this file; it is new, not a revision of a prior version.

What this repository is

HEADING OS is an operations engine for an AI executive assistant: a library of skills, always-on rules, automation scripts, and daemons that let an agent act as a strategic assistant across sessions, with Claude Code as the reference agent it is built for. This repository is the engine — code only, no private data, intended to be public. A companion private "data" repository (not part of this repo, and not present in a bare clone) holds the operator's actual contacts, knowledge, outputs, and credentials.

Setup

The canonical toolchain is uv; pyproject.toml is the source of truth for dependencies and uv.lock pins the resolved set.

uv sync --all-extras --group dev   # core + all integration extras + dev tools
cp .env.example .env               # fill in only the credentials you use
pre-commit install                 # arm the commit-time gates (see below)

A plain venv + pip path also works and is kept for tooling that cannot run uv. requirements.txt is a generated export of the full dependency graph (uv export --all-extras) for exactly this case — do not hand-edit it.

python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt   # add requirements-dev.txt for dev tooling
cp .env.example .env
pre-commit install

Running tests

Always invoke the interpreter inside .venv explicitly — .venv/bin/python, never a bare python — so you are not silently running against a different interpreter or a machine-wide install that lacks the pinned dependencies.

Read the full file on GitHub · 258 lines

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. today Changed · +2 lines · +30 tokens per session 1559969db404
  2. 3d ago First seen · 256 lines · 3,564 tokens per session scan A 55654c75f0d4

Subscribe to this mod's changes

heading-os AGENTS.md is an instructions file published in the GitHub repository mishahanin/heading-os (11 stars, last pushed yesterday), licensed Apache-2.0. It adds 3,594 tokens to every session, about $0.0180 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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