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/contentful/skill-kit/claude-mdgit clone --depth 1 https://github.com/contentful/skill-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 | $0.02399 | $0.02399 |
| Opus 5 | $0.01200 | $0.01200 |
| Sonnet 5 | $0.00480 | $0.00480 |
| Haiku 4.5 | $0.00240 | $0.00240 |
Grade A, and why
skill-kit CLAUDE.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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 100 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code 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 5.9+ (strict mode, ESM)
- Schema validation: Zod 4
- Test runner:
node --test --import tsx/esm, colocated*.test.tsfiles,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) usesbun build --compilefor standalone executables;--mode nodeuses esbuild for lightweight.mjsbundles
Commands
pnpm install— install dependenciespnpm exec tsc --noEmit— type checknode --test --import tsx/esm 'src/**/*.test.ts'— run all SDK testsnode --test --import tsx/esm examples/get-to-know-you/src/skill.test.ts— run workflow example testsnode --test --import tsx/esm examples/ts-patterns/src/skill.test.ts— run reference example testsnode --test --import tsx/esm examples/contentful-help/src/skill.test.ts— run composite example testspnpm run lint— lint with oxlintpnpm run lint:fix— lint and auto-fix with oxlintpnpm exec prettier --check .— check formattingpnpm exec prettier --write .— fix formattingnode --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
Example skills import @contentful/skill-kit which resolves via the exports field in the local package.json, not from a published npm package. After changing SDK source, run pnpm run build to compile the library before rebuilding examples.
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.
- 2d ago First seen · 100 lines · 2,399 tokens per session scan A 5a5f2722f3d3
skill-kit CLAUDE.md is an instructions file published in the GitHub repository contentful/skill-kit (66 stars, last pushed 5d ago), licensed MIT. It adds 2,399 tokens to every session, about $0.0120 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.
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.
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).
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
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
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.