To cite package ‘varnish’ in publications use:

  Davey R, Becker E, Kamvar Z (2026). _varnish: Front-end for The
  Carpentries Lesson Infrastructure_. R package version 1.1.3,
  <https://github.com/carpentries/varnish>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {varnish: Front-end for The Carpentries Lesson Infrastructure},
    author = {Robert Davey and Erin Becker and Zhian N. Kamvar},
    year = {2026},
    note = {R package version 1.1.3},
    url = {https://github.com/carpentries/varnish},
  }
