Filesystem

Frequently asked questions

What does the Filesystem MCP server do?

FieldCure MCP Filesystem Server A secure Model Context Protocol (MCP) server that exposes local filesystem operations to AI clients. Built with C and the official MCP C SDK. Features 17 filesystem tools : read, write, append, delete, search, copy, move, convert-to-markdown, and more Sandboxed access : all operations restricted to explicitly allowed directories MCP roots protocol : clients can change allowed directories at runtime without restarting the server Security hardened : path traversal prevention, symlink resolution, NTFS ADS blocking, Windows reserved name rejection Atomic writes : temp-file-then-rename pattern prevents data corruption Binary detection : automatically returns base64 for binary files, UTF-8 for text Built-in document parsing : supported document formats can be read directly and converted to markdown on disk Stdio transport : standard MCP subprocess model via JSON-RPC over stdin/stdout Installation dotnet tool From source Requirements .NET 8.0 Runtime or later Configuration Claude Desktop VS Code Tools File Operations Tool Description ------ ------------- read file Read file contents (text as UTF-8, binary as base64) read multiple files Read multiple files at once with per-file error handling read file lines Read a specific range of lines convert to markdown Convert one supported document file into a markdown file on disk convert directory to markdown Batch-convert supported document files in a directory to markdown files write file Create or overwrite a file with atomic write append file Append content to end of file with auto-newline modify file Find and replace text (plain text or regex) copy file Copy a file or directory recursively move file Move or rename a file or directory delete file Delete a file or directory Directory Operations Tool Description ------ ------------- list directory List contents with type markers, sizes, and dates create directory Create a directory recursively directory tree Hierarchical tree view with configurable depth Search & Info Tool Description ------ ------------- search files Find files by glob pattern search within files Search text content across files with line numbers get file info File or directory metadata MCP Roots Protocol The server supports the MCP roots protocol for runtime directory changes. When the client changes roots: The server requests the updated roots list. Allowed directories are replaced entirely. CLI args provide the initial sandbox. An empty roots list means all file access is denied. Security Model All paths are validated through IPathValidator before any filesystem operation: Allowed directories define the sandbox boundary. . and .. are normalized via Path.GetFullPath() . Symlinks must resolve within allowed directories. Prefix matching is directory-separator-aware. NTFS alternate data streams are blocked. Windows reserved names are rejected. Allowed directory updates are thread-safe. The markdown conversion tools validate both source and output paths through the same sandbox rules. They write converted markdown directly to disk instead of returning full document text through MCP, which is usually more token-efficient than read file plus write file . Project Structure Development Limitations Supported Not Yet Supported ----------- ------------------- Text file read/write (UTF-8) Non-UTF-8 encoding auto-detection Binary file detection + base64 Streaming for very large files (>100 MB) Atomic writes File watching / change notifications Glob pattern search Full-text indexing Regex find-and-replace Multi-file transactional writes Symlink resolution Cross-platform symlink creation MCP roots protocol HTTP transport Document text extraction / markdown conversion for formats supported by DocumentParsers OCR for scanned documents See Also Part of the AssistStudio ecosystem. License MIT

How do I install Filesystem?

Run the install command shown above, then paste the config for your client (Claude Desktop, Claude Code, Cursor, VS Code or Windsurf) into its MCP settings and restart the client.

Is Filesystem free to use?

The MCP server itself is free to install. The source is public on https://github.com/fieldcure/fieldcure-mcp-filesystem. Any third-party service it calls may require its own API key and account.

Which clients support Filesystem?

Any MCP-compatible client can use it, including Claude Desktop, Claude Code, Cursor, VS Code, Windsurf and custom agents.