To cite package ‘porcelain’ in publications use:

  FitzJohn R (2024). _porcelain: Turn a Package into an HTTP API_. R
  package version 0.1.15, <https://github.com/reside-ic/porcelain>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {porcelain: Turn a Package into an HTTP API},
    author = {Rich FitzJohn},
    year = {2024},
    note = {R package version 0.1.15},
    url = {https://github.com/reside-ic/porcelain},
  }