Clack is a Node.js CLI framework and prompt library designed for building stylized, interactive command-line user interfaces. It provides a toolkit for creating terminal applications that collect structured user input and display formatted information.
The library includes a set of interactive terminal UI components, such as validated input fields for text and passwords, searchable selection menus with autocomplete, and grouped options for user choice. It also provides mechanisms for process visualization, including loading spinners, progress bars, and sequential task lists to communicate background activity.
The framework covers terminal user interface design through the use of boxed text, notes, and structured layouts to improve readability. These capabilities are supported by an architecture that handles ANSI-based rendering and asynchronous input collection.