Americano

Americano puts a coffee cup in the menu bar: a left click opens its menu of preset durations, a right click toggles sleep prevention straight away. You can define your own time spans and a default, and its settings also cover display sleep and the screen saver.

It can stop on its own when the battery falls below a set level, when Low Power Mode turns on, or when the charger is connected or removed, and URL schemes let scripts start or stop it. The project requires macOS 14 or later and is distributed as a notarized ZIP on GitHub, through the developer's Homebrew tap, and as a free Mac App Store app.