---

name: julien-mcp-windows-manager description: "Manage MCP servers on Windows. Add, remove, list MCPs with proper cmd /c wrapper. Handles both global (~/.claude.json) and project (.mcp.json) configs." version: "1.0.0" license: Apache-2.0 metadata: author: "Julien" category: "infrastructure" triggers:

Keywords (removed generic "mcp" - causes false positives when mentioning any MCP server by name)

• "mcp server config"
• "mcp windows"
• "mcp.json"
• ".mcp.json"

Action phrases

• "add mcp"
• "ajouter mcp"
• "remove mcp"
• "supprimer mcp"
• "install mcp"
• "installer mcp"
• "configure mcp"
• "configurer mcp"
• "list mcp"
• "lister mcp"

Problem phrases

• "mcp connection closed"
• "mcp doesn't work"
• "mcp ne marche pas"
• "npx mcp error"
• "cmd /c mcp"

---

MCP Windows Manager

Manage MCP (Model Context Protocol) servers on Windows with proper configuration.

Observability

First: At the start of execution, display:

Copy🔧 Skill "julien-mcp-windows-manager" activated

Windows Specificity

Critical: On Windows, npx commands require cmd /c wrapper:

Copy{
  "command": "cmd",
  "args": ["/c", "npx", "-y", "package-name@latest"]
}

Without this, you get "Connection closed" errors.

Configuration Files

Priority: Project .mcp.json overrides global for same server name.

Quick Commands

List MCPs

Copynode -e "
const fs = require('fs');
const os = require('os');
const global = JSON.parse(fs.readFileSync(os.homedir() + '/.claude.json', 'utf-8'));
console.log('=== Global MCPs ===');
Object.keys(global.mcpServers || {}).forEach(n => console.log('  •', n));
try {
  const project = JSON.parse(fs.readFileSync('.mcp.json', 'utf-8'));
  console.log('=== Project MCPs ===');
  Object.keys(project.mcpServers || {}).forEach(n => console.log('  •', n));
} catch {}
"

Add MCP (Global)

Use the script:

Copynode ~/.claude/scripts/mcp-manager.js add <name> <npm-package>

Or manually edit ~/.claude.json:

Copy{
  "mcpServers": {
    "server-name": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@scope/package@latest"]
    }
  }
}

Add MCP (Project)

Create/edit .mcp.json in project root:

Copy{
  "mcpServers": {
    "my-server": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "my-mcp-server@latest"]
    }
  }
}

Remove MCP

Copynode ~/.claude/scripts/mcp-manager.js remove <name> [--global|--project]

Common MCP Configurations

NPX-based (most common)

Copy{
  "command": "cmd",
  "args": ["/c", "npx", "-y", "@modelcontextprotocol/server-filesystem", "C:/path"]
}

Python-based

Copy{
  "command": "python",
  "args": ["-m", "my_mcp_server"],
  "cwd": "C:/path/to/project",
  "env": { "PYTHONUNBUFFERED": "1" }
}

Node direct

Copy{
  "command": "node",
  "args": ["C:/path/to/server/index.js"],
  "env": { "API_KEY": "..." }
}

With reloaderoo (hot-reload)

Copy{
  "command": "reloaderoo",
  "args": ["proxy", "--", "node", "C:/path/to/index.js"]
}

Troubleshooting

"Connection closed" error

Cause: Missing cmd /c wrapper on Windows Fix: Change "command": "npx" to "command": "cmd" with "args": ["/c", "npx", ...]

MCP not loading

1. Check JSON syntax: node -e "JSON.parse(require('fs').readFileSync('.mcp.json'))"
2. Restart Claude Code after changes
3. Check MCP logs: /mcp command in Claude Code

Environment variables not working

Use env field in config:

Copy{
  "command": "...",
  "args": [...],
  "env": {
    "API_KEY": "your-key",
    "DEBUG": "true"
  }
}

CLI Alternative

Claude Code CLI also supports adding MCPs:

Copyclaude mcp add --transport stdio my-server -- cmd /c npx -y @some/package

Skill Chaining

Skills Required Before

• None

Input Expected

• MCP server name
• NPM package name (for add)
• Scope: global or project

Output Produced

• Updated config file
• Confirmation message

Compatible Skills After

• Restart Claude Code to load new MCP

Tools Used

• Bash (run node scripts, edit JSON)

Sources

• Claude Code MCP Docs
• Windows MCP Guide
• Issue #9594 - Windows npx wrapper