Tamp is a free, open-source menu bar app and CLI for macOS that wraps Apple's built-in caffeinate to keep your Mac awake — with one twist: it's the only keep-awake tool that tells you when something else is doing the caffeinating. If Amphetamine, a background script, or an AI coding agent is holding your Mac open, Tamp's icon fills in and shows exactly why, so you never have to guess. The menu bar app and the tamp CLI share one state, so you can toggle from the terminal and watch the icon respond, or set a timer in the menu and check it with tamp status --json. Display, system, and disk sleep can each be controlled independently. It's a universal binary (Apple Silicon + Intel), roughly 1 MB, MIT-licensed, needs no background daemon, and installs in one line via Homebrew. It's built for developers running long tasks, automated jobs, or AI agent workflows who want a single glanceable indicator instead of wondering why their Mac won't sleep.