Filesystem MCP Server

Node.js server implementing Model Context Protocol (MCP) for filesystem operations.

Features

• Read/write files
• Create/list/delete directories
• Move files/directories
• Search files
• Get file metadata
• Dynamic directory access control via Roots

Directory Access Control

The server uses a flexible directory access control system. Directories can be specified via command-line arguments or dynamically via Roots.

Method 1: Command-line Arguments

Specify Allowed directories when starting the server:

mcp-server-filesystem /path/to/dir1 /path/to/dir2

Method 2: MCP Roots (Recommended)

MCP clients that support Roots can dynamically update the Allowed directories.

Roots notified by Client to Server, completely replace any server-side Allowed directories when provided.

Important: If server starts without command-line arguments AND client doesn't support roots protocol (or provides empty roots), the server will throw an error during initialization.

This is the recommended method, as this enables runtime directory updates via roots/list_changed notifications without server restart, providing a more flexible and modern integration experience.

How It Works

The server's directory access control follows this flow:

1. Server Startup

   • Server starts with directories from command-line arguments (if provided)
   • If no arguments provided, server starts with empty allowed directories

2. Client Connection & Initialization

   • Client connects and sends initialize request with capabilities
   • Server checks if client supports roots protocol (capabilities.roots)

3. Roots Protocol Handling (if client supports roots)

   • On initialization: Server requests roots from client via roots/list
   • Client responds with its configured roots
   • Server replaces ALL allowed directories with client's roots
   • On runtime updates: Client can send notifications/roots/list_changed
   • Server requests updated roots and replaces allowed directories again

4. Fallback Behavior (if client doesn't support roots)

   • Server continues using command-line directories only
   • No dynamic updates possible

5. Access Control

   • All filesystem operations are restricted to allowed directories
   • Use list_allowed_directories tool to see current directories
   • Server requires at least ONE allowed directory to operate

Note: The server will only allow operations within directories specified either via args or via Roots.

API

Resources

• file://system: File system operations interface

Tools

• read_file

  • Read complete contents of a file
  • Input: path (string)
  • Reads complete file contents with UTF-8 encoding

• read_multiple_files

  • Read multiple files simultaneously
  • Input: paths (string[])
  • Failed reads won't stop the entire operation

• write_file

  • Create new file or overwrite existing (exercise caution with this)
  • Inputs:
    • path (string): File location
    • content (string): File content

• edit_file

  • Make selective edits using advanced pattern matching and formatting
  • Features:
    • Line-based and multi-line content matching
    • Whitespace normalization with indentation preservation
    • Multiple simultaneous edits with correct positioning
    • Indentation style detection and preservation
    • Git-style diff output with context
    • Preview changes with dry run mode
  • Inputs:
    • path (string): File to edit
    • edits (array): List of edit operations
      • oldText (string): Text to search for (can be substring)
      • newText (string): Text to replace with
    • dryRun (boolean): Preview changes without applying (default: false)
  • Returns detailed diff and match information for dry runs, otherwise applies changes
  • Best Practice: Always use dryRun first to preview changes before applying them

• create_directory

  • Create new directory or ensure it exists
  • Input: path (string)
  • Creates parent directories if needed
  • Succeeds silently if directory exists

• list_directory

  • List directory contents with [FILE] or [DIR] prefixes
  • Input: path (string)

• move_file

  • Move or rename files and directories
  • Inputs:
    • source (string)
    • destination (string)
  • Fails if destination exists

• search_files

  • Recursively search for files/directories
  • Inputs:
    • path (string): Starting directory
    • pattern (string): Search pattern
    • excludePatterns (string[]): Exclude any patterns. Glob formats are supported.
  • Case-insensitive matching
  • Returns full paths to matches

• get_file_info

  • Get detailed file/directory metadata
  • Input: path (string)
  • Returns:
    • Size
    • Creation time
    • Modified time
    • Access time
    • Type (file/directory)
    • Permissions

• list_allowed_directories

  • List all directories the server is allowed to access
  • No input required
  • Returns:
    • Directories that this server can read/write from

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

Note: you can provide sandboxed directories to the server by mounting them to /projects. Adding the ro flag will make the directory readonly by the server.

Docker

Note: all directories must be mounted to /projects by default.

{
  "mcpServers": {
    "filesystem": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "--mount", "type=bind,src=/Users/username/Desktop,dst=/projects/Desktop",
        "--mount", "type=bind,src=/path/to/other/allowed/dir,dst=/projects/other/allowed/dir,ro",
        "--mount", "type=bind,src=/path/to/file.txt,dst=/projects/path/to/file.txt",
        "mcp/filesystem",
        "/projects"
      ]
    }
  }
}

NPX

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/Users/username/Desktop",
        "/path/to/other/allowed/dir"
      ]
    }
  }
}

Usage with VS Code

For quick installation, click the installation buttons below...

For manual installation, add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open Settings (JSON).

Optionally, you can add it to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

Note that the mcp key is not needed in the .vscode/mcp.json file.

You can provide sandboxed directories to the server by mounting them to /projects. Adding the ro flag will make the directory readonly by the server.

Docker

Note: all directories must be mounted to /projects by default.

{
  "mcp": {
    "servers": {
      "filesystem": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "--mount", "type=bind,src=${workspaceFolder},dst=/projects/workspace",
          "mcp/filesystem",
          "/projects"
        ]
      }
    }
  }
}

NPX

{
  "mcp": {
    "servers": {
      "filesystem": {
        "command": "npx",
        "args": [
          "-y",
          "@modelcontextprotocol/server-filesystem",
          "${workspaceFolder}"
        ]
      }
    }
  }
}

Build

Docker build:

docker build -t mcp/filesystem -f src/filesystem/Dockerfile .

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.