AgentSync is a free, cross-platform command-line interface (CLI) tool designed to simplify the management of AI agent configurations across various coding assistants. By establishing a single source of truth in the `.agents/` directory, it enables seamless synchronization of configurations, ensuring that all AI tools reference the same set of files. The application supports symbolic links instead of copies, allowing for instant updates across multiple locations, which is crucial for developers working with diverse AI tools such as Claude Code, GitHub Copilot, and OpenAI Codex.

Key features of AgentSync include a user-friendly TOML configuration format, automated management of `.gitignore` files, and a curated collection of over 200 skills spanning multiple technologies. Additionally, it provides robust catalog validation to ensure installed skills are correctly resolved. With its CI-friendly design and cross-platform compatibility, AgentSync is an essential tool for developers looking to streamline their AI coding assistant setups.