fs-mcp 0.4.0

A secure MCP filesystem server with Stdio and Web UI modes.

filesystem-mcp 📂

A secure, production-grade filesystem server for the Model Context Protocol (MCP).

Bridge your local files to LLMs safely. Works with Claude Desktop, Cursor, and any MCP-compliant agent.

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Why This Exists

If you're building agents or using tools like Claude Desktop, you know the struggle: giving an LLM access to your files is often "all or nothing" and setting up a proper server usually involves Node.js dependency hell.

FS-MCP solves this. It's a single, dependency-free (via uv) Python package that gives you:

1. Strict Security: Sandbox enforcement so agents can't touch /etc/passwd or escape via symlinks.
2. Dual Mode by Default: Launch a standard MCP server PLUS a built-in inspector Streamlit Web UI simultaneously. No more jumping through hoops with npm inspector clients.
3. Zero Config: Run it instantly with uvx. No cloning required.

The goal: A filesystem tool that is robust enough for production agents but friendly enough for quick local debugging.

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What You Get

🤖 For Agents (HTTP/Stdio Mode)

A full suite of tools optimized for LLM consumption:

• edit_file: Precise "Find and Replace" with expected_replacements validation. No more accidental file mangling.
• append_text: A reliable fallback for dumping content to the end of files when diffs get too complex.
• read_multiple_files: Read 10+ files in one turn (saves tokens & round-trips).
• directory_tree: High-performance recursive views with smart ignores (.venv, .git) and depth limits.

👨‍💻 For Humans (Web UI Explorer)

The built-in UI is now a first-class citizen:

• Auto-Copy Clipboard: Successful tool responses are instantly copied to your clipboard. Run a tool in the UI, paste the result into Claude. Done.
• Native Schema Discovery: Uses FastMCP's internal inspection to export 100% accurate JSON schemas for your agent configuration.
• Live Tool Testing: Run tools manually with an interactive form to verify behavior.

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Quick Start

1. Run Instantly

By default, this command launches the Web UI (8123) and a Background HTTP Server (8124).

# Allow access to the current dir
uvx fs-mcp .

2. Selective Launch (Flags)

Want to disable a component? Use the inverted "No" flags:

# UI Only
fs-mcp --no-http .

# HTTP Only (Headless)
fs-mcp --no-ui .

3. Configure Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "fs-mcp": {
      "command": "uvx",
      "args": [
        "--from", "fs-mcp", "fs-mcp", "--no-ui",
        "/absolute/path/to/your/project"
      ]
    }
  }
}

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The Toolbox 🧰

Tool	Description
list_allowed_directories	List the directories this server is allowed to access.
list_directory	Get a detailed listing of all files and directories.
list_directory_with_sizes	Get listing with file sizes.
directory_tree	Fast: Returns recursive JSON tree. Skips .venv/.git automatically.
search_files	Fast: Recursive pattern discovery using rglob.
get_file_info	Metadata retrieval (size, modified time, etc.).
read_text_file	Read text file contents.
read_multiple_files	Reads content of multiple files. Essential for context loading.
read_media_file	Returns base64 encoded images/audio.
write_file	Creates or overwrites files (atomic operations).
create_directory	Create a new directory or ensure it exists.
move_file	Move or rename files.
edit_file	Robust find/replace with occurrence safety checks.
append_text	Safe fallback for appending content to EOF.
grounding_search	Placeholder for custom RAG/Search implementations.

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License & Credits

Built with ❤️ for the MCP Community by luutuankiet. Powered by FastMCP and Streamlit.

Now go build some agents. 🚀