To cite package ‘altair’ in publications use:

  Lyttle I, Jeppson H, Altair Developers (2024). _altair: Interface to
  'Altair'_. R package version 5.2.0.9002, ,
  <https://github.com/vegawidget/altair>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {altair: Interface to 'Altair'},
    author = {Ian Lyttle and Haley Jeppson and {Altair Developers}},
    year = {2024},
    note = {R package version 5.2.0.9002, 
},
    url = {https://github.com/vegawidget/altair},
  }