Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/leefowlercu/agent-kit/agents-mdgit clone --depth 1 https://github.com/leefowlercu/agent-kitWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00976 | $0.00976 |
| Opus 5 | $0.00488 | $0.00488 |
| Sonnet 5 | $0.00195 | $0.00195 |
| Haiku 4.5 | $0.00098 | $0.00098 |
Grade A, and why
agent-kit 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
This file provides guidance to Codex and Claude Code when working with code in this repository.
Project Overview
Agent Kit is a Claude Code and Codex plugin marketplace that extends agent capabilities through Skills, Subagents, Hooks, and MCP Server components. Plugins are organized in the plugins/ directory and registered in .claude-plugin/marketplace.json for Claude Code and .agents/plugins/marketplace.json for Codex.
Repository Architecture
.claude-plugin/
├── marketplace.json # Claude Code plugin registry
└── README.md
.agents/plugins/
├── marketplace.json # Codex plugin registry
└── README.md
plugins/
└── {plugin-name}/
├── .claude-plugin/
│ └── plugin.json # Claude Code plugin metadata
├── .codex-plugin/
│ └── plugin.json # Codex plugin metadata
├── README.md # Plugin documentation (required)
├── .mcp.json # MCP server configuration (optional)
├── agents/ # Custom agents or subagents (optional)
│ └── {agent}.md # Markdown with frontmatter
├── skills/ # Agent skills (optional)
│ └── {skill-name}/
│ ├── SKILL.md # Main skill definition (frontmatter + workflow)
│ ├── README.md # Skill documentation
│ ├── references/ # Supporting docs, schemas, templates
│ └── scripts/ # Validation/automation scripts
├── hooks/ # Event hooks (optional)
│ └── hooks.json # Hook configuration
└── scripts/ # Hook and utility scripts (optional)
└── {script}.sh|.py|.js
Repository Development
Updating marketplace.json
When modifying .claude-plugin/marketplace.json, reference the Claude Code plugin marketplace documentation. When modifying .agents/plugins/marketplace.json, reference the Codex plugin marketplace documentation.
Developing Plugins
When developing or updating plugins, reference the current Claude Code and Codex plugin documentation:
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.
- yesterday First seen · 125 lines · 976 tokens per session scan A 61adfb8c4a30
agent-kit AGENTS.md is an instructions file published in the GitHub repository leefowlercu/agent-kit (6 stars, last pushed 29d ago), licensed MIT. It adds 976 tokens to every session, about $0.0049 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.
Other instructions, from other repositories
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
buildNext
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
spec-kit AGENTS.md
Instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
langchain AGENTS.md
Instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.