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/cmwen/mcp-dev-env-setup/agents-mdgit clone --depth 1 https://github.com/cmwen/mcp-dev-env-setupWhat 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 | $0.02058 | $0.02058 |
| Opus 5 | $0.01029 | $0.01029 |
| Sonnet 5 | $0.00412 | $0.00412 |
| Haiku 4.5 | $0.00206 | $0.00206 |
Grade B, and why
mcp-dev-env-setup AGENTS.md scanned grade B with 1 finding 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
2. **Permission denied**: May need sudo for system-wide installations How it starts
The opening of the file, as written. The whole thing — 321 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AI Agent Integration Guide
This document provides guidance for AI agents (like Claude, ChatGPT, etc.) that want to use or contribute to this MCP server.
Project Overview
mcp-dev-env-setup is a Model Context Protocol (MCP) server that automates the setup of development environments across macOS and Linux systems. It provides intelligent package manager detection and cross-platform tool installation capabilities.
Architecture
Core Principles
- Modular Design: The codebase is organized into distinct modules with clear responsibilities
- Platform Agnostic: Automatically detects OS and package manager to provide appropriate installation methods
- Extensible: Easy to add new tools and package managers
- Testable: Comprehensive unit tests for all core functionality
Module Structure
src/
├── core/ # Core business logic
│ ├── package-manager.ts # OS and package manager detection
│ └── tool-config.ts # Tool definitions and configurations
├── installers/ # Installation modules
│ └── unified-installer.ts # Unified installation logic
├── validators/ # Validation modules
│ └── environment-validator.ts # Environment checking and validation
├── utils/ # Utility functions
│ ├── shell.ts # Shell command execution
│ └── check.ts # Environment checking utilities
├── tools/ # Legacy tool implementations
│ └── install.ts # Original installation functions
└── __tests__/ # Unit tests
├── package-manager.test.ts
├── tool-config.test.ts
└── shell.test.ts
Key Modules
1. Package Manager Detection (core/package-manager.ts)
Purpose: Automatically detect the operating system and available package manager.
Key Functions:
detectOS(): Identifies the current operating systemdetectPackageManager(): Finds the available package managergetSystemInfo(): Returns comprehensive system informationinstallPackage(): Installs a package using the detected package manager
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 · 321 lines · 2,058 tokens per session scan B c21802cf899e
mcp-dev-env-setup AGENTS.md is an instructions file published in the GitHub repository cmwen/mcp-dev-env-setup (0 stars, last pushed 11mo ago), licensed MIT. It adds 2,058 tokens to every session, about $0.0103 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other instructions, from other repositories
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).
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.
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.
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.
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.