Filesystem MCP server

This MCP (Model Context Protocol) server provides filesystem operations with controlled access to specified directories. It allows you to safely perform file and directory operations while restricting access to only the directories you explicitly permit.

Configuration

Set the allowed directories using the environment variable MCP_ALLOWED_DIRS:

export MCP_ALLOWED_DIRS="/path1,/path2,/path with spaces/dir3"

Installation

Install the server using Go:

go get github.com/gomcpgo/filesys

After installation, build the executable:

go build -o bin/filesys cmd/main.go

Integration with Claude Desktop

To use the filesystem MCP server with Claude Desktop, add the following to your claude_desktop_config.json:

{
  "mcpServers": {
    "filesystem": {
      "command": "/path/to/filesys",
      "env": {
        "MCP_ALLOWED_DIRS": "/path1,/path2,/path with spaces/dir3"
      }
    }
  }
}

Available Tools

File Reading Operations

• read_file: Read contents of a single file
• read_multiple_files: Read multiple files simultaneously

File Writing Operations

• write_file: Create or overwrite files

Directory Operations

• create_directory: Create new directories
• list_directory: List directory contents
• list_allowed_directories: Display all accessible directories

File Management Operations

• move_file: Move or rename files and directories
• get_file_info: Retrieve file metadata
• search_files: Search files recursively with pattern matching

Usage Examples

Reading a File

To read the contents of a file:

{
    "name": "read_file",
    "arguments": {
        "path": "/allowed/path/file.txt"
    }
}

Listing Directory Contents

To list all contents within a directory:

{
    "name": "list_directory",
    "arguments": {
        "path": "/allowed/path"
    }
}

Security Features

The server implements several security measures:

• Operations are restricted to allowed directories only
• Path traversal attacks are prevented
• Permission validation occurs before any operations
• Proper error handling and logging is implemented
• Thread-safe caching of allowed directories

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "filesystem" '{"command":"/path/to/filesys","env":{"MCP_ALLOWED_DIRS":"/path1,/path2,/path with spaces/dir3"}}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "filesystem": {
            "command": "/path/to/filesys",
            "env": {
                "MCP_ALLOWED_DIRS": "/path1,/path2,/path with spaces/dir3"
            }
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "filesystem": {
            "command": "/path/to/filesys",
            "env": {
                "MCP_ALLOWED_DIRS": "/path1,/path2,/path with spaces/dir3"
            }
        }
    }
}

3. Restart Claude Desktop for the changes to take effect