MCP Filesystem Server Setup: How I Ran It on My Laptop

MCP filesystem server setup takes Node.js, one command and one folder. You start the official server with the path of a test folder. Then an AI app can list, read and edit files inside that folder only. I ran it on a Windows 10 laptop: the first start took 24 seconds because npx had to download the package.

What do you need before you start the MCP filesystem server?

You need three things: Node.js, a terminal and a folder you are happy to share. Claude Desktop is only needed for the last part of this guide. If you are new to the idea, read what Model Context Protocol is first. This post is only about the setup.

How did I set up the MCP filesystem server step by step?

I did five things. Each one gave me a result I could check.

Step 1: I checked that Node.js was installed

First I ran this in a terminal. It printed v24.16.0, so Node.js was ready. If your terminal says the command is not found, install Node.js first.

node --version

Step 2: I made a throwaway folder

Next I made a new folder only for this test. I put two text files in it: os-unit2.txt with the words "Operating Systems unit 2 notes" and dbms-pyq.txt with "DBMS pyq 2024". Why a throwaway folder? The server can edit files, so I did not want to risk my real study notes.

Step 3: I started the server

Then I ran the package from the official guide and pointed it at my test folder. Put your own folder path in place of mine.

npx -y @modelcontextprotocol/server-filesystem "C:\path\to\your\test-folder"

The first start took 24 seconds, because npx had to download the package. After that the server printed that it was running on stdio. It also listed my test folder as the only allowed one.

Only the folder path at the end changes from one setup to the next.

Step 4: I asked the server for its tools

I wrote a small script that sends MCP messages to the server over stdio. You do not need one, because an AI app sends these messages for you. The server introduced itself as secure-filesystem-server, version 2.2.0. When I asked for its tool list, it sent back 16 tools.

I sorted the 16 names into three groups myself: look, read and change. Six of them can change your files. That matters in the safety section below.

Step 5: I tested the folder limit

This was the part I cared about most, because the whole point of sharing one folder is that the server must stay inside it. First I called list_directory on my test folder, which showed both files. Then I called read_text_file on os-unit2.txt and got back "Operating Systems unit 2 notes". Last I asked it to read C:\Windows\win.ini, a file outside my folder.

The server refused the last request. So the folder list you give it really is the limit, at least for this server version.

How do I connect the server to Claude Desktop?

You add the server to one config file, then restart the app. I did not run any of this myself, because I left my real Claude Desktop settings alone. The approval prompt, the Developer tab and the restart come only from the official guide.

1. Install Claude Desktop and Node.js.

2. In Claude Desktop, open the Claude menu, then Settings, then the Developer tab and click Edit Config. On Windows the file is at %APPDATA%\Claude\claude_desktop_config.json.

3. Put the server in that file. Swap username for your own Windows username and change the two folders to the ones you want to share.

4. Quit Claude Desktop completely, open it again and try a request like "What files are in my Downloads folder?" The docs say Claude asks for your approval before it does anything on your computer.

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

Write every backslash in a Windows path twice inside the file, exactly as the docs example does.

What would I check if the setup does not work?

I would start at the top of this table and go down. The first row is from my own test. I did not hit the other rows, so they are what I would check first, based on the docs.

Is it safe to share a folder with an MCP server?

It is safe enough if you stay careful. In my test the server refused a file outside the folder I gave it. Still, six of the 16 tools can change files. The docs say a local server runs with the permissions of your own user account.

Frequently asked questions

Do I need to install the package first?

No. I did not install anything by hand. The npx command downloaded the package on the first start. That is why the first start took 24 seconds.

Can I share more than one folder?

Yes. The docs example for Claude Desktop lists two folders, Desktop and Downloads. Each folder is one more path in the list.

Where is the config file on Windows?

The docs give the path as %APPDATA%\Claude\claude_desktop_config.json. You can also reach it from Claude Desktop through Settings, the Developer tab and Edit Config.

Does the server only work with Claude Desktop?

No. I ran it with my own small script and no AI app at all. The docs list other apps that support MCP, such as Visual Studio Code and Cursor. I did not try them.

What I would do next

The part I have not tried is the Claude Desktop approval prompt, so that is my next test. If you want to understand why the server behaves this way, read what Model Context Protocol is. For more guides like this one, browse the Tool Setup posts.