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/us-all/mcp-toolkit/claude-mdgit clone --depth 1 https://github.com/us-all/mcp-toolkitWrote 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.
[](https://agentmods.dev/instructions/us-all/mcp-toolkit/claude-md)<a href="https://agentmods.dev/instructions/us-all/mcp-toolkit/claude-md"><img src="https://agentmods.dev/badge/instructions/us-all/mcp-toolkit/claude-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.03620 | $0.03620 |
| Opus 5 | $0.01810 | $0.01810 |
| Sonnet 5 | $0.00724 | $0.00724 |
| Haiku 4.5 | $0.00362 | $0.00362 |
Grade A, and why
mcp-toolkit 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 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.
How it starts
The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
이 파일은 Claude Code가 이 저장소에서 작업할 때 참고하는 컨텍스트입니다.
프로젝트 개요
@us-all/mcp-toolkit — @us-all/* MCP 서버용 공통 빌딩 블록. 6개 production MCP에서 검증된 토큰 효율 패턴을 단일 npm 패키지로 추출.
- 타겟: Node 18+, ESM, TypeScript strict
- Peer deps:
@modelcontextprotocol/sdk^1.27 || ^1.28 || ^1.29,zod^4 - 목적: 6 production MCP의 코드 중복 제거 + 패턴 진화 시 단일 진실 소스
- 표준 문서: STANDARD.md — 패턴의 why, 이 패키지는 how
디렉토리
src/
├── extract-fields.ts # applyExtractFields(data, expr?) — 응답 필드 프로젝션
├── registry.ts # ToolRegistry<TCategory> + createSearchToolsMetaTool + parseEnvList
├── wrap-tool-handler.ts # createWrapToolHandler — 에러 sanitize + structured 응답 + extractFields auto-apply
├── aggregate.ts # aggregate(fetchers, caveats) — Promise.allSettled + 라벨링된 caveats 보일러플레이트 통합
├── runtime.ts # startMcpServer(server, opts?) — stdio + Streamable HTTP (node:http + Bearer auth)
└── index.ts # re-export 통합 진입점
tests/
├── extract-fields.test.ts # 9 cases — wildcards, backtick keys, projection 엣지
├── registry.test.ts # 11 cases — search 매칭, 카테고리 토글, allowlist/denylist
├── wrap-tool-handler.test.ts # 16 cases — 성공/에러 경로, 커스텀 redaction, errorExtractors
├── aggregate.test.ts # 11 cases — 성공/거부 mix, 커스텀 formatReason, 동시성 검증
└── runtime.test.ts # 7 cases — 환경변수/옵션 해석, Bearer 인증, /health, skipAuth
STANDARD.md # us-all MCP 작성 표준 (패턴 가이드)
Build & Run
pnpm install
pnpm build # tsc → dist/
pnpm test # 36 unit tests
설계 원칙
- Pure functions / pure classes: 외부 의존성 없는 도메인-독립 코드만 추출. SDK/auth 등 도메인 특수 로직은 각 repo에 유지.
- Generic categories:
ToolRegistry<TCategory>— 각 repo가 자체CATEGORIES상수를 typed로 정의해서 사용. - Always-enabled meta:
meta카테고리는 기본적으로 항상 활성.alwaysEnabled옵션으로 커스터마이즈 가능. - Schema opt-in:
extractFields는 각 도구 schema가 명시적으로 선언해야 동작 (MCP SDK가 미선언 필드를 validation에서 drop). STANDARD.md에 caveat 명시.
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.
- 3d ago First seen · 152 lines · 3,620 tokens per session scan A 43c44962f149
mcp-toolkit CLAUDE.md is an instructions file published in the GitHub repository us-all/mcp-toolkit (0 stars, last pushed 1mo ago), licensed MIT. It adds 3,620 tokens to every session, about $0.0181 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
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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.
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langchain AGENTS.md
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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).
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.