Connect to local MCP servers

Learn how to extend Claude Desktop with local MCP servers to enable file system access and other powerful integrations

Model Context Protocol (MCP) servers extend AI applications’ capabilities by providing secure, controlled access to local resources and tools. Many clients support MCP, enabling diverse integration possibilities across different platforms and applications.

This guide demonstrates how to connect to local MCP servers using Claude Desktop as an example, one of the many clients that support MCP. While we focus on Claude Desktop’s implementation, the concepts apply broadly to other MCP-compatible clients. By the end of this tutorial, Claude will be able to interact with files on your computer, create new documents, organize folders, and search through your file system—all with your explicit permission for each action.

Prerequisites

Before starting this tutorial, ensure you have the following installed on your system:

Claude Desktop

Download and install Claude Desktop for your operating system. Claude Desktop is currently available for macOS and Windows. Linux support is coming soon.

If you already have Claude Desktop installed, verify you’re running the latest version by clicking the Claude menu and selecting “Check for Updates…”

Node.js

The Filesystem Server and many other MCP servers require Node.js to run. Verify your Node.js installation by opening a terminal or command prompt and running:

node --version

If Node.js is not installed, download it from nodejs.org. We recommend the LTS (Long Term Support) version for stability.

Understanding MCP Servers

MCP servers are programs that run on your computer and provide specific capabilities to Claude Desktop through a standardized protocol. Each server exposes tools that Claude can use to perform actions, with your approval. The Filesystem Server we’ll install provides tools for:

• Reading file contents and directory structures
• Creating new files and directories
• Moving and renaming files
• Searching for files by name or content

All actions require your explicit approval before execution, ensuring you maintain full control over what Claude can access and modify.

Installing the Filesystem Server

The process involves configuring Claude Desktop to automatically start the Filesystem Server whenever you launch the application. This configuration is done through a JSON file that tells Claude Desktop which servers to run and how to connect to them.

1. Open Claude Desktop Settings

   Start by accessing the Claude Desktop settings. Click on the Claude menu in your system’s menu bar (not the settings within the Claude window itself) and select “Settings…”

   On macOS, this appears in the top menu bar:

   

   This opens the Claude Desktop configuration window, which is separate from your Claude account settings.

2. Access Developer Settings

   In the Settings window, navigate to the “Developer” tab in the left sidebar. This section contains options for configuring MCP servers and other developer features.

   Click the “Edit Config” button to open the configuration file:

   

   This action creates a new configuration file if one doesn’t exist, or opens your existing configuration. The file is located at:

   • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
   • Windows: %APPDATA%\Claude\claude_desktop_config.json
3. Configure the Filesystem Server

   Replace the contents of the configuration file with the following JSON structure. This configuration tells Claude Desktop to start the Filesystem Server with access to specific directories:

   macOS

   {
     "mcpServers": {
       "filesystem": {
         "command": "npx",
         "args": [
           "-y",
           "@modelcontextprotocol/server-filesystem",
           "/Users/username/Desktop",
           "/Users/username/Downloads"
         ]
       }
     }
   }
   

   Replace username with your actual computer username. The paths listed in the args array specify which directories the Filesystem Server can access. You can modify these paths or add additional directories as needed.

   Understanding the Configuration

   • "filesystem": A friendly name for the server that appears in Claude Desktop
   • "command": "npx": Uses Node.js’s npx tool to run the server
   • "-y": Automatically confirms the installation of the server package
   • "@modelcontextprotocol/server-filesystem": The package name of the Filesystem Server
   • The remaining arguments: Directories the server is allowed to access

   Security Consideration

   Only grant access to directories you’re comfortable with Claude reading and modifying. The server runs with your user account permissions, so it can perform any file operations you can perform manually.

4. Restart Claude Desktop

   After saving the configuration file, completely quit Claude Desktop and restart it. The application needs to restart to load the new configuration and start the MCP server.

   Upon successful restart, you’ll see an MCP server indicator in the bottom-right corner of the conversation input box:

   

   Click on this indicator to view the available tools provided by the Filesystem Server:

   

   If the server indicator doesn’t appear, refer to the Troubleshooting section for debugging steps.

Using the Filesystem Server

With the Filesystem Server connected, Claude can now interact with your file system. Try these example requests to explore the capabilities:

File Management Examples

• “Can you write a poem and save it to my desktop?” - Claude will compose a poem and create a new text file on your desktop
• “What work-related files are in my downloads folder?” - Claude will scan your downloads and identify work-related documents
• “Please organize all images on my desktop into a new folder called ‘Images’” - Claude will create a folder and move image files into it

How Approval Works

Before executing any file system operation, Claude will request your approval. This ensures you maintain control over all actions:

Review each request carefully before approving. You can always deny a request if you’re not comfortable with the proposed action.

Troubleshooting

If you encounter issues setting up or using the Filesystem Server, these solutions address common problems:

Server not showing up in Claude / hammer icon missing

1. Restart Claude Desktop completely
2. Check your claude_desktop_config.json file syntax
3. Make sure the file paths included in claude_desktop_config.json are valid and that they are absolute and not relative
4. Look at logs to see why the server is not connecting
5. In your command line, try manually running the server (replacing username as you did in claude_desktop_config.json) to see if you get any errors:

macOS/Linux

npx -y @modelcontextprotocol/server-filesystem /Users/username/Desktop /Users/username/Downloads

Getting logs from Claude Desktop

Claude.app logging related to MCP is written to log files in:

• macOS: ~/Library/Logs/Claude

• Windows: %APPDATA%\Claude\logs

• mcp.log will contain general logging about MCP connections and connection failures.

• Files named mcp-server-SERVERNAME.log will contain error (stderr) logging from the named server.

You can run the following command to list recent logs and follow along with any new ones (on Windows, it will only show recent logs):

macOS/Linux

tail -n 20 -f ~/Library/Logs/Claude/mcp*.log

Tool calls failing silently

If Claude attempts to use the tools but they fail:

1. Check Claude’s logs for errors
2. Verify your server builds and runs without errors
3. Try restarting Claude Desktop

None of this is working. What do I do?

Please refer to our debugging guide for better debugging tools and more detailed guidance.

ENOENT error and `${APPDATA}` in paths on Windows

If your configured server fails to load, and you see within its logs an error referring to ${APPDATA} within a path, you may need to add the expanded value of %APPDATA% to your env key in claude_desktop_config.json:

{
  "brave-search": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-brave-search"],
    "env": {
      "APPDATA": "C:\\Users\\user\\AppData\\Roaming\\",
      "BRAVE_API_KEY": "..."
    }
  }
}

With this change in place, launch Claude Desktop once again.

NPM should be installed globally

The npx command may continue to fail if you have not installed NPM globally. If NPM is already installed globally, you will find %APPDATA%\npm exists on your system. If not, you can install NPM globally by running the following command:

npm install -g npm

Next Steps

Now that you’ve successfully connected Claude Desktop to a local MCP server, explore these options to expand your setup:

Explore other servers

Browse our collection of official and community-created MCP servers for additional capabilities

Build your own server

Create custom MCP servers tailored to your specific workflows and integrations

Connect to remote servers

Learn how to connect Claude to remote MCP servers for cloud-based tools and services

Understand the protocol

Dive deeper into how MCP works and its architecture