state‑tree is a low‑level JavaScript library that provides a single mutable state tree with an explicit API (`set`, `push`, `merge`, etc.) while automatically tracking references between nodes. It records every change and can flush a concise change‑description object, enabling apps (especially UI frameworks) to subscribe to precise updates, support relational data, and avoid the performance penalties of full immutability. The project is aimed at front‑end developers who need fine‑grained, performant state management with reference handling.