Harness-for-codex: Instructions file for Codex

AGENTS.md

Harness-for-codex AGENTS.md is an instructions file for Codex, OpenCode from ganimjeong/Harness-for-codex. It costs 687 tokens per session, scanned A, original, MIT.

Instructions for Codex in a repository built as a harness, or test workspace, for agent-driven development. It documents the project layout and standard scripts for setup, checks, tests, evaluation, diagnosis, and Git hooks.

In plain words
What is it for?
Use it to prepare the environment, inspect readiness, run linting and tests, install hooks, and perform the complete handoff evaluation.
Why use it?
It gives an agent one documented task loop and stable commands instead of requiring it to discover the project workflow manually.

Instructions file for CodexOpenCode

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

This is ganimjeong/Harness-for-codex's own configuration. It tells Codex and OpenCode how to work on Harness-for-codex 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 Harness-for-codex configures →

Reuse

Borrowing it

Nothing to install: this file belongs to ganimjeong/Harness-for-codex. 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/ganimjeong/Harness-for-codex/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/ganimjeong/Harness-for-codex

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 Harness-for-codex AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/ganimjeong/harness-for-codex/agents-md.svg)](https://agentmods.dev/instructions/ganimjeong/harness-for-codex/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/ganimjeong/harness-for-codex/agents-md"><img src="https://agentmods.dev/badge/instructions/ganimjeong/harness-for-codex/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 687 This file is loaded in full into every session.
When invoked 687 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 $0.00687 $0.00687
Opus 5 $0.00344 $0.00344
Sonnet 5 $0.00137 $0.00137
Haiku 4.5 $0.00069 $0.00069

Measured 7d ago against content hash 839a55b9971d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

Harness-for-codex 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 7d 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 · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Codex Harness Instructions

This repository is a baseline workspace for Codex-driven implementation.

Commands

Run these from the repository root:

scripts/bootstrap
scripts/check
scripts/test
scripts/eval
scripts/doctor
scripts/hooks
  • scripts/bootstrap: prepare dependencies when a known stack is present.
  • scripts/check: run lint, type checks, formatting checks, and tests when available.
  • scripts/test: run only the test suite when available.
  • scripts/eval: run the complete handoff verification sequence.
  • scripts/doctor: report repository, tool, and environment readiness.
  • scripts/hooks: install local Git hooks through pre-commit when available.

Repository Layout

  • AGENTS.md: Codex instructions for this repo.
  • CLAUDE.md: Claude Code bridge that imports AGENTS.md.
  • README.md: Human-facing overview and workflow.
  • harness.yml: Machine-readable harness metadata and command registry.
  • .devcontainer/: Optional reproducible development container.
  • .pre-commit-config.yaml: Optional local hook definitions.
  • docs/: Project notes and decisions.
  • scripts/: Stable automation entrypoints.
  • tasks/: Task briefs and working notes.

Operating Principles

  • Read the repository before editing. Prefer existing conventions over new ones.
  • Keep changes scoped to the requested task.
  • Do not revert user changes unless explicitly asked.
  • Use rg for searching when available.
  • Use the standard scripts instead of one-off local commands when they cover the task.
  • Add or update tests when behavior changes.
  • Document decisions that affect future work in docs/decisions.md.
  • Add nested AGENTS.md files in subdirectories only when that area needs different instructions.
  • Keep root-level agent instructions short and durable. Move long procedures into docs or scripts.

Task Loop

  1. Inspect: read relevant files and recent decisions.
  2. Plan: identify the narrow change and verification path.
  3. Implement: make focused edits.
  4. Verify: run scripts/check or scripts/eval.
  5. Handoff: summarize changed files, verification, and residual risks.

Read the full file on GitHub · 85 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. 7d ago First seen · 85 lines · 687 tokens per session scan A 839a55b9971d

Subscribe to this mod's changes

Harness-for-codex AGENTS.md is an instructions file published in the GitHub repository ganimjeong/Harness-for-codex (46 stars, last pushed 3mo ago), licensed MIT. It adds 687 tokens to every session, about $0.0034 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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