rle‑extents is a small Node.js library that takes a run‑length‑encoded (RLE) narrowband level‑set volume and returns its axis‑aligned bounding box as a pair of 3‑D coordinate arrays. It’s aimed at developers working with compressed volumetric data—e.g., 3D geometry or simulation pipelines—who need a quick way to compute the spatial extents of an RLE‑encoded volume.