Semiparametric Principal Stratification Analysis Beyond Monotonicity R package PSor version 0.1.0 Estimates principal causal effects under principal stratification using a margin-free, conditional odds ratio sensitivity parameter. This framework unifies the monotonicity assumption and the counterfactual intermediate independence assumption, allowing for robust analysis when monotonicity may not hold. Computes point estimates, standard errors, and confidence intervals for conditionally doubly robust and debiased machine learning estimators. The methodological details are described in Tong, Kahan, Harhay, and Li (2025) <doi:10.48550/arXiv.2501.17514>. Software Imports: stats, SuperLearner, caret, dplyr, geex, magrittr, numDeriv Suggests: testthat (>= 3.0.0), knitr, rmarkdown Jiaqi Tong <jiaqi.tong@yale.edu> Comprehensive R Archive Network (CRAN) Jiaqi Tong [aut, cre] (ORCID: <https://orcid.org/0009-0005-8922-3386>), Brennan Kahan [ctb], Michael O. Harhay [ctb], Fan Li [ctb] MIT + file LICENSE (https://CRAN.R-project.org/package=PSor/LICENSE) 2026-04-24 application/tgz https://CRAN.R-project.org/package=PSor doi:10.32614/CRAN.package.PSor en-US