Planager is an open‑source, web‑based environment that lets designers and makers build and run live data‑flow toolchains for digital fabrication. It combines a Python library (with Flask and SocketIO) for defining modular processing pipelines with a Lit‑based JavaScript front‑end, enabling interactive, real‑time control of fabrication workflows. The project is aimed at developers, researchers, and digital‑fabrication artists who need a flexible, programmable framework for prototyping and managing dynamic toolchains.