foghorn: Instructions file for Codex

AGENTS.md

foghorn AGENTS.md is an instructions file for Codex, OpenCode from sandeep-alluru/foghorn. It costs 133 tokens per session, scanned A, a copy of groundcrew AGENTS.md, MIT.

An AGENTS.md project guide for foghorn, a system that alerts AI agents when decisions may be outdated. It describes the project, its modules, testing commands, and areas that still need documentation.

In plain words
What is it for?
Use it when working on the foghorn repository, especially to find its stated test, lint, and type-check commands.
Why use it?
It gives coding agents project-specific context before they make changes. The document is incomplete, so some invariants and protected areas are not yet explained.

Instructions file for CodexOpenCode

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

This is sandeep-alluru/foghorn's own configuration. It tells Codex and OpenCode how to work on foghorn 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 foghorn configures →

Reuse

Borrowing it

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

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 foghorn AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/sandeep-alluru/foghorn/agents-md.svg)](https://agentmods.dev/instructions/sandeep-alluru/foghorn/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/sandeep-alluru/foghorn/agents-md"><img src="https://agentmods.dev/badge/instructions/sandeep-alluru/foghorn/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 133 This file is loaded in full into every session.
When invoked 133 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 86% copy Near-identical to another mod 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 $0.00133 $0.00133
Opus 5 $0.00067 $0.00067
Sonnet 5 $0.00027 $0.00027
Haiku 4.5 $0.00013 $0.00013

Measured 6d ago against content hash c262a3f5c758, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

foghorn 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.

Origin

This is a copy

86% identical to groundcrew AGENTS.md — 6 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

AGENTS.md · 31 lines

What it actually says

foghorn — Agent Context

This file describes the project architecture for AI coding assistants (Claude Code, Cursor, Copilot).

What this project does

Decision staleness alerts for AI agents

Module map

src/foghorn/
├── # TODO: fill in module map

Key invariants

  • TODO: document invariants that must not be broken

Testing

make test       # full test suite
make lint       # ruff check + format
make typecheck  # mypy

What NOT to change without careful thought

  • TODO: list protected areas

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 First seen · 31 lines · 133 tokens per session scan A c262a3f5c758

Subscribe to this mod's changes

foghorn AGENTS.md is an instructions file published in the GitHub repository sandeep-alluru/foghorn (0 stars, last pushed 20d ago), licensed MIT. It adds 133 tokens to every session, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to groundcrew AGENTS.md, differing in 6 lines, and is treated as a copy.

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