Hammerspoon

Hammerspoon is a macOS automation tool that acts as a bridge between the operating system and a Lua scripting engine. It provides direct access to macOS APIs for applications, windows, mouse pointers, filesystem objects, audio devices, batteries, screens, and low-level keyboard/mouse events. This allows users to create custom automation scripts that can interact with nearly every aspect of their Mac's functionality.

The tool works by exposing specific pieces of system functionality through extensions, which users can control with Lua scripts. Users create a configuration file that connects system events to actions—for example, binding keyboard shortcuts to window operations, running commands when wifi connects to specific networks, or displaying alerts when battery levels drop. The community contributes pre-made plugins called Spoons that extend Hammerspoon's capabilities without requiring users to write everything from scratch.

Hammerspoon is particularly valuable for Mac power users, developers, and system administrators who want to automate repetitive tasks or create custom workflows. It's ideal for creating personalized window management systems, automating application-specific shortcuts, or building complex event-driven automation based on location, network status, or hardware changes. Since it's open-source and extensible, advanced users can even contribute their own extensions to expose new areas of system functionality.