Filesystem MCP Server

What is Filesystem MCP Server?

A secure Model Context Protocol (MCP) server that provides a standardized interface for interacting with the local filesystem. It allows clients to perform common file operations such as listing directories, reading files, and searching file contents in a controlled manner, with all operations constrained to configurable allowed directories for security.

How to use Filesystem MCP Server?

Build the server using Cargo (cargo build --release), then run the binary with optional flags: --allowed-dirs for comma-separated directory paths, --config-file for a file listing directories, or --max-file-size to limit file reads. Environment variables (FS_ALLOWED_DIRS, FS_CONFIG_FILE, FS_MAX_FILE_SIZE, FS_REQUEST_TIMEOUT, FS_LOG_LEVEL, FS_LOG_FILE) can also configure the server.

Key features of Filesystem MCP Server

• Provides 11 MCP tools including list, read, write, mkdir, delete, copy, move, info, search, edit, and list_allowed_dirs.
• All operations are constrained to configurable allowed directories for security.
• Supports partial file edits via replace, insert, delete, and replace_lines operations.
• Search functionality supports regex, glob file patterns, recursive search, and context lines.
• Configurable via command-line flags, configuration files, or environment variables.
• Built with Rust for performance and reliability.

Use cases of Filesystem MCP Server

• Allow AI assistants to securely read and write files within designated project directories.
• Automate batch file operations like search-and-replace across multiple files.
• Provide controlled filesystem access for MCP-based tools and workflows.

FAQ from Filesystem MCP Server

What runtime does Filesystem MCP Server require?

It requires the Rust toolchain (1.70.0 or later) and Cargo package manager to build. The compiled binary runs on any supported platform without additional runtime dependencies.

How are security and access control handled?

All filesystem operations are constrained to a set of configurable allowed directories. The server validates paths to prevent directory traversal attacks, and operations targeting files outside allowed directories are rejected with error messages.

What operating systems are supported?

The server can be built for Linux, macOS, and Windows using appropriate Cargo targets.

How do I configure which directories the server can access?

You can specify allowed directories via the --allowed-dirs command-line flag (comma-separated), a configuration file with one directory per line using --config-file, or the FS_ALLOWED_DIRS environment variable.

What file sizes are supported?

Read operations enforce a configurable maximum file size. The default limit is 1 MB for reads and 10 MB for searches, adjustable via the --max-file-size flag or FS_MAX_FILE_SIZE environment variable.