Stan Model Adjustments and Sensitivity Analyses using Importance Sampling R package adjustr version 0.2.0 Assess the sensitivity of a Bayesian model (fitted using 'Stan' via 'rstan', 'brms', or 'cmdstanr') to the specification of its likelihood and priors. Users provide a series of alternate sampling specifications, and the package uses Pareto-smoothed importance sampling (PSIS) to estimate posterior quantities of interest under each specification, without needing to refit the model. Methods are based on Vehtari, Simpson, Gelman, Yao, and Gabry (2024) <doi:10.48550/arXiv.1507.02646>. Software Depends: R (>= 3.6.0), dplyr (>= 1.0.0) Imports: rlang, tidyselect, rstan, loo Suggests: ggplot2, extraDistr, tidyr, testthat, covr, knitr, rmarkdown Cory McCartan <mccartan@psu.edu> Comprehensive R Archive Network (CRAN) Cory McCartan [aut, cre, cph] MIT + file LICENSE (https://CRAN.R-project.org/package=adjustr/LICENSE) 2026-05-29 application/tgz https://CRAN.R-project.org/package=adjustr doi:10.32614/CRAN.package.adjustr