What is ai-instruct-sync?

instruct-sync is a command line tool that keeps the instruction files used by different AI coding assistants in sync with each other. Tools like Cursor, Windsurf, GitHub Copilot, Claude Code, Aider, Gemini CLI, and Continue each expect their own rules file, such as a folder for Cursor or a single CLAUDE.md file for Claude Code. Over time these separate files tend to drift apart, so one assistant may follow different style rules than another, and code reviews and AI behavior become inconsistent. The tool solves this by detecting which rules files exist in a project, showing you the differences between them, and converting or copying content from one tool's format into another. It defaults to a dry run mode, meaning it shows you what would change without actually writing anything until you explicitly confirm with an apply flag, and it automatically backs up files before making changes. You install it globally with npm or run it directly through npx without installing anything permanently. It requires Node.js version 20 or newer and has no other runtime dependencies. Typical commands let you check what rules files are currently installed in a project, see the differences between them, preview a sync from one tool's rules into the others, and apply that sync once you are satisfied with the preview. This particular GitHub repository is actually the home for a wider collection of related developer tools built by the same author, described as an AI development hygiene suite covering things like rules syncing, setup diagnostics, secret scanning for AI related paths, and spend control, though instruct-sync itself is the most complete and published piece. The repository documentation points newcomers interested specifically in rules syncing to start with the instruct-sync folder rather than the other, earlier stage tools bundled alongside it. The project is released under the MIT license.