Enables users to build 'ToxPi' prioritization models and provides functionality within the grid framework for plotting ToxPi graphs. 'toxpiR' allows for more customization than the 'ToxPi GUI' (< https://toxpi.github.io/>) and integration into existing workflows for greater ease-of-use, reproducibility, and transparency. toxpiR package behaves nearly identically to the GUI; the package documentation includes notes about all differences. The vignettes download example files from < https://github.com/ToxPi/ToxPi-example-files>.