skill-kit: Instructions file for Codex

AGENTS.md

skill-kit AGENTS.md is an instructions file for Codex, OpenCode from contentful/skill-kit. It costs 2,828 tokens per session, scanned A, a copy of skill-kit CLAUDE.md, MIT.

A set of project instructions for contributors working on a TypeScript toolkit used to build agent skills. It documents the repository's technology, design guidance, and standard commands.

In plain words
What is it for?
It is for guiding development work in the skill-kit repository, including type checking, tests, linting, formatting, and builds.
Why use it?
It gives coding agents a shared reference for how the project is structured, tested, formatted, and built.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: reads .claude/ paths; mentions Claude Code.

This is contentful/skill-kit's own configuration. It tells Codex and OpenCode how to work on skill-kit 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 skill-kit configures →

Reuse

Borrowing it

Nothing to install: this file belongs to contentful/skill-kit. 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/contentful/skill-kit/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/contentful/skill-kit

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 skill-kit AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/contentful/skill-kit/agents-md.svg)](https://agentmods.dev/instructions/contentful/skill-kit/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/contentful/skill-kit/agents-md"><img src="https://agentmods.dev/badge/instructions/contentful/skill-kit/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 2,828 This file is loaded in full into every session.
When invoked 2,828 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 92% 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 $0.02828 $0.02828
Opus 5 $0.01414 $0.01414
Sonnet 5 $0.00566 $0.00566
Haiku 4.5 $0.00283 $0.00283

Measured 3d ago against content hash f97a0e2a66df, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

skill-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 3d 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

92% identical to skill-kit CLAUDE.md — 126 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 · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Guide

This is the canonical instruction file for all coding agents working in this repository.

Project

@contentful/skill-kit — TypeScript SDK for building agent skills with CLI-driven workflows. Companion to @contentful/agents-kit.

Read SPEC.md before any substantive work. It is the source of truth for the SDK's design, primitives, and protocol. The notes below are a reading guide, not a replacement.

Tech stack

  • Runtime: Node.js 24+ with tsx for dev
  • Package manager: pnpm
  • Language: TypeScript 7 for repository checks (strict mode, ESM)
  • Schema validation: ArkType for public/runtime schemas; Zod 4 for MCP tool input schemas
  • Test runner: node --test --import tsx/esm, colocated *.test.ts files, node:assert/strict
  • Linting: oxlint (correctness + suspicious rules; style rules off — Prettier owns formatting)
  • Formatting: Prettier (singleQuote: true, printWidth: 120)
  • Build/distribution: --mode bun (default) uses bun build --compile for standalone executables; --mode node uses esbuild for lightweight .mjs bundles

Commands

  • pnpm install — install dependencies
  • pnpm exec tsc --noEmit — type check
  • node --test --import tsx/esm 'src/**/*.test.ts' — run all SDK tests
  • node --test --import tsx/esm examples/get-to-know-you/src/skill.test.ts — run workflow example tests
  • node --test --import tsx/esm examples/ts-patterns/src/skill.test.ts — run reference example tests
  • node --test --import tsx/esm examples/contentful-help/src/skill.test.ts — run composite example tests
  • pnpm run lint — lint with oxlint
  • pnpm run lint:fix — lint and auto-fix with oxlint
  • pnpm exec prettier --check . — check formatting
  • pnpm exec prettier --write . — fix formatting
  • node --import tsx/esm bin/skill-kit.js build <entry.ts> -o <outdir> --single — build a skill executable (dev, current platform)
  • node --import tsx/esm bin/skill-kit.js build <entry.ts> -o <outdir> --mode node — build a skill as a Node.js bundle

Read the full file on GitHub · 126 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. 3d ago First seen · 126 lines · 2,828 tokens per session scan A f97a0e2a66df

Subscribe to this mod's changes

skill-kit AGENTS.md is an instructions file published in the GitHub repository contentful/skill-kit (66 stars, last pushed yesterday), licensed MIT. It adds 2,828 tokens to every session, about $0.0141 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to skill-kit CLAUDE.md, differing in 126 lines, and is treated as a copy.

Related

Other instructions, from other repositories

next.js AGENTS.md

AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens

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.

openai/codex · 5,182 tokens

vscode buildNext.instructions.md

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).

microsoft/vscode · 6,785 tokens

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).

microsoft/vscode · 5,001 tokens

langchain AGENTS.md

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.

langchain-ai/langchain · 4,469 tokens

spec-kit AGENTS.md

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.

github/spec-kit · 7,104 tokens