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agent-harness-skills: Instructions file for Codex

AGENTS.md

agent-harness-skills AGENTS.md is an instructions file for Codex, OpenCode from yfge/agent-harness-skills. It costs 450 tokens per session, scanned A, original, MIT.

Repository instructions for creating reusable skills for AI coding agents, including required file structure, sections, checks, and examples.

In plain words
What is it for?
Writing, reviewing, and validating agent skills in a repository, including names, frontmatter, documentation structure, and commit discipline.
Why use it?
They help keep skills consistent, generic, and free of project-specific secrets or assumptions.

Instructions file for CodexOpenCode

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

This is yfge/agent-harness-skills's own configuration. It tells Codex and OpenCode how to work on agent-harness-skills 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 agent-harness-skills configures →

not rated 10repo 1mo ago A scan 450 tokens original MIT
View source ↗ yfge/agent-harness-skills
Reuse

Borrowing it

Nothing to install: this file belongs to yfge/agent-harness-skills. 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/yfge/agent-harness-skills/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/yfge/agent-harness-skills

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
[![agentmods](https://agentmods.dev/badge/instructions/yfge/agent-harness-skills/agents-md.svg)](https://agentmods.dev/instructions/yfge/agent-harness-skills/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/yfge/agent-harness-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/yfge/agent-harness-skills/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 450 This file is loaded in full into every session.
When invoked 450 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 $0.00450 $0.00450
Opus 5 $0.00225 $0.00225
Sonnet 5 $0.00090 $0.00090
Haiku 4.5 $0.00045 $0.00045

Measured 8d ago against content hash 27ff4ec3db88, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

agent-harness-skills 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 8d 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 · 33 lines

How it starts

The opening of the file, as written. The whole thing — 33 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Harness Skills - Repository Instructions

Purpose

This repository contains reusable skills for building agent-first harnesses across software projects. Keep the skills general-purpose: they should help an agent assess, design, validate, and deliver repo harness work without copying any single product's private workflow.

Rules

  • Keep each skill in skills/<skill-name>/SKILL.md.
  • Skill folder names and frontmatter name values must be lowercase kebab-case.
  • Frontmatter description must start with Use when and describe triggering conditions only.
  • Every skill must keep these sections in order: Overview, When To Use, Inputs Needed, Execution Order, Step-by-Step Process, Checks, Output Format, Common Mistakes, Example Prompts.
  • Use bilingual repository documentation where appropriate: README files are split by language, but every SKILL.md must be English-only.
  • Keep examples repo-neutral and engineering-form agnostic. Source repositories may inform authoring privately, but committed guidance must contain only distilled generic patterns.
  • Do not add project-specific secrets, URLs, credentials, or private environment assumptions.

Validation

  • Run python3 scripts/validate_skill_quality.py before committing.
  • Run python3 scripts/check_skill_language.py before committing skill wording changes.
  • Run python3 scripts/check_skill_closure.py before committing skill workflow/reference changes.
  • Run python3 scripts/check_reference_neutrality.py before committing public skill references or repository guidance.
  • Run python3 scripts/check_profile_consistency.py before committing profile or template changes.
  • Run python3 scripts/validate_plugin_metadata.py before committing plugin or extension metadata changes.
  • Run node --check .opencode/plugins/agent-harness-skills.js before committing OpenCode plugin entrypoint changes.
  • For substantial wording changes, test the skill with at least one realistic prompt and record the observed output manually in the commit or PR notes.

Read the full file on GitHub · 33 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. 8d ago First seen · 33 lines · 450 tokens per session scan A 27ff4ec3db88

Subscribe to this mod's changes

agent-harness-skills AGENTS.md is an instructions file published in the GitHub repository yfge/agent-harness-skills (10 stars, last pushed 1mo ago), licensed MIT. It adds 450 tokens to every session, about $0.0022 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 2026-08-31.

Building agentsagent-harnessagent-readyai-agentscoding-agentsdeveloper-toolsdevtools
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