Guard

Guard is a command-line tool designed for developers who use AI coding agents and need to prevent unintended file modifications. It works by toggling Unix file permissions, ownership, and immutable flags to protect files from being changed by AI tools like Claude, Cursor, or GitHub Copilot. Guard stores original permission states in a .guardfile and can restore them on demand, giving developers precise control over which files an AI can touch.

• Individual file protection — Run guard add file <path> and guard enable file <path> to lock a specific file against AI modifications.
• Collection management — Group related files into named collections and toggle protection for the entire set with a single command.
• Interactive TUI mode — Launch guard -i to open a terminal UI with a file tree, fuzzy search, and keyboard shortcuts for the fastest possible workflow.
• Fuzzy search — Press / in interactive mode to instantly filter the file tree and find files to guard or unguard.
• Permission state memory — Guard records each file's original owner, group, and rwx permissions in .guardfile and restores them exactly when protection is disabled.
• Immutable flag support — Sets the immutable flag so even the file owner cannot change permissions without sudo, ensuring AI agents cannot silently bypass protection.
• Safe cleanup utilities — Use guard cleanup to remove stale registry entries and guard reset to disable all active protections while preserving registrations.
• Unix-only design — Supports Linux, macOS, and BSD variants; Windows users are directed to WSL, Docker, or a Linux VM.
• Cobra-based CLI — Built with Go and the Cobra framework; install via git clone, just build, and just install into $GOPATH/bin.
• Comprehensive test suite — Includes unit tests, property-based tests (gopter), and integration tests covering real filesystem operations.