CreatorOfMia/MCP_FileSystem

Secure Filesystem MCP Server (Python)

A Python re-implementation of the Secure Filesystem MCP Server from the official Model Context Protocol (MCP) project.

This version ports the original TypeScript/Node server to Python using FastMCP, preserving the same core functionality (file read/write/edit/move/search, directory listing with sizes, metadata, JSON tree views) and enforcing strict allowed directories security.

What’s in this repo?

• Feature parity with the original filesystem server:
  • read_text_file (with head/tail)
  • read_media_file (Base64 + MIME)
  • write_file, edit_file (diff preview), move_file
  • create_directory, list_directory, list_directory_with_sizes
  • directory_tree (JSON), search_files, get_file_info
  • list_allowed_directories
• Python-native implementation using FastMCP
• Security-first path validation against configured allowed directories
• Minimal dependencies, runs over stdio for easy MCP client integration

Why rewrite it in Python?

• Provide a Python-native MCP server for teams/environments that prefer Python
• Demonstrate a clean port from the official TypeScript server to FastMCP
• Reduce runtime/dependency footprint (no Node.js required)

Quick start

# Recommended: uv
uv run fileServer.py /path/to/allowed/dir [more/dirs...]

# Or plain Python
python3 fileServer.py /path/to/allowed/dir [more/dirs...]

The server communicates via stdio, so it is fully compatible with any MCP-enabled client.

Connecting the Filesystem MCP Server to Claude Desktop (This example is done on Mac)

To connect this Python-based Secure Filesystem MCP Server to Claude Desktop, follow these steps:

1. Make sure the server runs correctly on its own:

   uv run /absolute/path/to/fileServer.py /absolute/path/to/allowed/directory
   

2. Open your Claude MCP configuration file:
   • Open Claud Desktop
   • Go to Settings
   • Go to Developer
   • Click Edit Config
   • Open claude_desktop_config.json
   • Paste/Add the following configuration:

     {
       "mcpServers": {
         "filesystem": {
           "command": "/Users/USERNAME/.local/bin/uv",
             "args": [
               "run",
               "/absolute/path/to/fileServer.py",
               "/absolute/path/to/allowed/directory"
             ]
         }
       }
     }
     

3. Save the file.
4. Fully restart Claude to reload your updated MCP configuration.
5. Start a new chat — Claude should now automatically detect your MCP filesystem server and list it as an available tool.

Tip:
Use absolute paths and choose directories you’re comfortable granting full read/write access to.

Security Model

• You must specify one or more allowed directories at startup.
• All operations validate and resolve paths (including symlinks) and deny access outside the configured directories.
• Unauthorized paths return descriptive errors.