I built Arness: a Claude Code plugin marketplace you drive with four slash commands

Claude Code is powerful. Without structure around it, every session starts cold, plans live in chat history, and the spec you cared about is buried in a thread you will never re-read. I built Arness because I got tired of two things at once: the ad-hoc-prompting ceiling, and the ceremony every framework adds when it tries to fix it. It is an open-source Claude Code plugin marketplace, and you drive it with four slash commands. The four commands These are the user-facing surface. You do not pick