npm-dev-mcp: Instructions file for Codex

AGENTS.md

npm-dev-mcp AGENTS.md is an instructions file for Codex, OpenCode from masamunet/npm-dev-mcp. It costs 918 tokens per session, scanned A, original, MIT.

Repository instructions for npm-dev-mcp, a TypeScript project that provides an MCP server and command-line tools. They describe the project layout, coding conventions, build and test commands, and process management.

In plain words
What is it for?
Use them when editing source files, building the project, running Jest tests, checking coverage, or managing the service with PM2.
Why use it?
They give an unfamiliar developer the rules needed to change the repository consistently and verify that it still works.

Instructions file for CodexOpenCode

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

This is masamunet/npm-dev-mcp's own configuration. It tells Codex and OpenCode how to work on npm-dev-mcp 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 npm-dev-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to masamunet/npm-dev-mcp. 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/masamunet/npm-dev-mcp/master/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/masamunet/npm-dev-mcp

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 npm-dev-mcp AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/masamunet/npm-dev-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/masamunet/npm-dev-mcp/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/masamunet/npm-dev-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/masamunet/npm-dev-mcp/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for npm-dev-mcp AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/masamunet/npm-dev-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/masamunet/npm-dev-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 918 This file is loaded in full into every session.
When invoked 918 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 $0.00918 $0.00918
Opus 5.5 $0.00367 $0.00367
Sonnet 5.5 $0.00184 $0.00184
Haiku 4.5 $0.00092 $0.00092

Measured 2mo ago against content hash 45c04fcbf182, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

npm-dev-mcp 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 2mo 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 · 38 lines

What it actually says

Repository Guidelines

プロジェクト構成と配置

  • エントリーポイントは src/index.ts、ビルド成果物は dist/ に生成されます(npm run build)。
  • コア機能は src/components/(プロセス・ポート・ログ管理)、src/tools/(MCPツール定義)、src/cli/(コマンド登録と出力整形)に分割。
  • 実行時設定・健康チェックは src/config/ と src/components/HealthEndpoint.ts、状態復旧は src/components/StateManager.ts。
  • テストは tests/ 配下と src/**/__tests__/ を対象に Jest が走ります。
  • ログと PM2 用設定は logs/ と ecosystem.config.js を参照してください。

ビルド・テスト・開発コマンド

  • npm run dev : TypeScript をウォッチコンパイル(開発用)。
  • npm run build : tsc で dist/ を生成(公開前フロー)。
  • npm start : ビルド済み dist/index.js を実行。
  • npm test / npm run test:watch / npm run test:coverage : Jest 実行。Coverage は coverage/ に出力。
  • 運用プロセス管理: npm run pm2:start|stop|restart|delete|logs|monit|status(ecosystem.config.js を基に pm2 で常駐)。

コーディングスタイル・命名

  • 言語: TypeScript (ES2022, module=NodeNext, ESM import は拡張子 .js を付与)。
  • インデント2スペース、セミコロン必須、シングルクォート推奨。
  • 型安全を優先(strict: true)。パブリック API は明示的な型・インターフェースを付与。
  • ロガーは utils/logger.ts のシングルトンを利用し、標準出力汚染を避ける。
  • ファイル/クラス名は役割ベース(例: *Manager, *Handler, *Schema)。

テスト指針

  • フレームワーク: Jest + ts-jest (ESM)。対象パターン: **/__tests__/**/*.test.ts および **/*.(spec|test).ts。
  • 可能ならユースケース単位でモジュールを分離し、プロセス管理系はモックで外部副作用を隔離。
  • 新機能は少なくとも正常系と主要なエラー系を追加し、npm run test:coverage で回帰確認。

コミットと Pull Request

  • 既存ログは短い命令形/バージョンタグ例 (Fix ..., 1.1.4)。同様のトーンで簡潔に。
  • PR には目的、変更点、テスト結果(実行コマンド名と要約)、関連 Issue/チケットを記載。
  • 機能やCLI挙動が変わる場合は README/ヘルプ出力の更新を忘れずに。スクリーンショットよりは実行ログや例を添付するとレビューしやすい。

セキュリティ・運用メモ

  • Node.js 18+ を前提。.env は自動検出されるため、秘密情報はコミットしないこと(.gitignore を尊重)。
  • デーモン化時は pm2 のログローテーション設定を確認し、logs/ の肥大化を定期確認。
  • MCP 経由でツールを公開する場合、外部入力は SafeErrorHandler を通し、例外は JSON で整形して返却する。
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. 2mo ago First seen · 38 lines · 918 tokens per session scan A 45c04fcbf182

Subscribe to this mod's changes

npm-dev-mcp AGENTS.md is an instructions file published in the GitHub repository masamunet/npm-dev-mcp (0 stars, last pushed 10mo ago), licensed MIT. It adds 918 tokens to every session, about $0.0037 per session on Opus 5.5. 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.

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