MCP Configurator Server

A Model Context Protocol (MCP) server that provides tools to manage, edit, backup, and validate Claude Desktop and other client JSON configurations.

This application is built with the official @modelcontextprotocol/sdk and zod for argument schema validation, enabling client LLMs (like Claude or ChatGPT) to programmatically read and modify their own configuration and environment setups.

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Folder Structure

mcp-configurator/
├── lib/
│   ├── backup.js       # Handles backup creation, listing, and restores
│   ├── config.js       # Handles JSON loading, syntax validation, and updates
│   ├── validator.js    # Checks system path command executable existence
│   └── utils.js        # Filepath resolvers and cross-platform defaults
├── backups/            # Stores configuration backup files (.bak)
├── package.json        # Project metadata and dependencies (type: module)
├── server.js           # Server entry point running StdioServerTransport
└── README.md           # Documentation

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Installation

1. Install Dependencies: Open a terminal in the project directory and run:

   npm install
   

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Running the Server

Since it uses Stdio transport, the server is meant to be spawned by an MCP host (such as Claude Desktop or Cursor). You can run it manually to check for syntax or launch issues:

npm start

Note: This command will run and listen on stdin/stdout. You will see MCP Configurator server running on stdio outputted to stderr to avoid polluting the JSON-RPC channel.

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Integration Setup

1. Claude Desktop Configuration

To add this configurator server to Claude Desktop on Windows, open your %APPDATA%\Claude\claude_desktop_config.json and add the mcp-configurator to your mcpServers list:

{
  "mcpServers": {
    "mcp-configurator": {
      "command": "node",
      "args": [
        "C:/Desktop/my workspace/work/server.js"
      ]
    }
  }
}

Replace C:/Desktop/my workspace/work/server.js with the actual absolute path to where you saved this project.

2. Cursor or other Local IDEs

For Cursor or VS Code, configure a new stdio-based MCP client with:

• Command: node
• Arguments: C:/Desktop/my workspace/work/server.js

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Tool Descriptions

The server registers the following tools:

get_config

Reads a configuration JSON file.

• Input:
  • path (string, optional): Custom absolute path to the configuration JSON file. If omitted, defaults to the current system's Claude Desktop config file path.
• Output:
  • The full JSON config payload.

save_config

Saves configuration JSON after automatically creating a timestamped backup of the current state.

• Input:
  • path (string, required): Absolute path to the file to overwrite.
  • config (object, required): The new JSON configuration object.
• Output:
  • Success message with the name of the backup created.

list_backups

Lists all available configuration backups under the backups/ workspace directory.

• Input: None.
• Output:
  • Formatted list of all files detailing filename, backup date, and file size.

restore_backup

Reverts the target configuration file using a selected backup file. Creates a new backup of the current state before overwriting as a safety measure.

• Input:
  • filename (string, required): Filename of the backup (e.g. claude_desktop_config.json.bak-2026-07-08T11-04-05-123Z).
  • path (string, optional): Custom absolute path to restore into. Defaults to the active configuration path.
• Output:
  • Confirmation message of successful restoration.

validate_command

Spawns standard shell diagnostic tools (where on Windows, which on macOS/Linux) or queries paths to confirm if an executable exists on the host machine. Helpful for verifying if custom MCP server commands (e.g. npx, python, git) are executable.

• Input:
  • command (string, required): The executable binary name or absolute path to check.
• Output:
  • JSON object indicating success status, resolved PATH location, and descriptive message.