To cite package ‘grumpy’ in publications use:

  Gruson H, Smith M (2026). _grumpy: Read 'NumPy' '.npy' and '.npz'
  Files_. R package version 0.1.1.9000,
  <https://github.com/bisaloo/grumpy>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {grumpy: Read 'NumPy' '.npy' and '.npz' Files},
    author = {Hugo Gruson and Mike Smith},
    year = {2026},
    note = {R package version 0.1.1.9000},
    url = {https://github.com/bisaloo/grumpy},
  }