BASS is an R package for fitting Bayesian Adaptive Spline Surface models available on CRAN with a development version available on GitHub. BASS models most closely resemble Bayesian multivariate adaptive regression splines (Bayesian MARS).
To install the development version, use
# install.packages("devtools")
::install_github("lanl/BASS") devtools
Examples of uses are in Francom et al. (2018) and Francom et al. (2019) and explicit code examples are given in the R package vignette.