Alien Signals is a tiny, high‑performance JavaScript reactivity library that implements a push‑pull signal algorithm inspired by Vue 3, Preact, Svelte and Reactively. It provides a simple API (`signal`, `computed`, `effect`, scopes, manual triggering) for building reactive state in any front‑end framework, and its core algorithm has been adopted by Vue 3.6, XState and various language ports. The project is aimed at library authors and developers who need ultra‑lightweight, fast reactive primitives for UI or tooling code.