Cross-platform filesystem path configuration for MCP Server Filesystem

Problem

When using the MCP Server Filesystem on both macOS and Windows platforms, the settings synchronization mechanism in VS Code causes issues with filesystem paths. Every time settings are synchronized, the path configured for one platform overwrites the other, causing the MCP filesystem server to stop working on the other platform.

Background

In the current implementation, filesystem paths are directly configured in the VS Code settings.json file like this:

"mcp": {
  "servers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "${input:file_system_path}"  // Or hardcoded path like "C:/Projects"
      ]
    }
  },
  "inputs": [
    {
      "id": "file_system_path",
      "type": "promptString",
      "description": "File System Path"
    }
  ]
}

The issue occurs because Windows paths (e.g., "C:\Projects") and macOS paths (e.g., "/Users/username/Projects") are incompatible, and when settings sync happens, one overwrites the other.

Proposed Solution

Implement a platform-specific configuration option for filesystem paths in the MCP Server Filesystem. Some options:

1. Platform-specific inputs: Allow different input variables for different platforms:

"mcp": {
  "inputs": [
    {
      "id": "file_system_path_windows",
      "type": "promptString",
      "description": "File System Path (Windows)"
    },
    {
      "id": "file_system_path_macos",
      "type": "promptString", 
      "description": "File System Path (macOS)"
    }
  ],
  "servers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "${os:windows?input:file_system_path_windows:input:file_system_path_macos}"
      ]
    }
  }
}

2. Automatic platform detection: Modify the filesystem server to automatically handle platform-specific paths:

// In server code
const platformPath = os.platform() === 'win32' 
  ? process.env.WINDOWS_PATH 
  : process.env.MACOS_PATH;

3. VS Code conditional settings: Support a conditional syntax or settings overrides based on platform.

Benefits

• Users can maintain a single synchronized settings.json that works on all platforms
• No more broken MCP filesystem server on platform switching
• Smoother cross-platform development experience

Affected Components

• MCP Server Filesystem
• VS Code settings handling

Would appreciate if this could be considered for an upcoming release. This would greatly improve the experience for developers working across multiple platforms.

Start by locating the MCP Server Filesystem entry point and the VS Code settings handling described in the issue. Compare the proposed platform-specific inputs, automatic detection, and conditional settings approaches before choosing a design. Done means one synchronized settings.json works with distinct Windows and macOS filesystem paths without breaking the server.