Bayesian Power Prior Design for Survival Outcomes R package BayesPPDSurv version 1.0.5 Bayesian power/type I error calculation and model fitting using the power prior and the normalized power prior for time-to-event endpoints. The proportional hazards model with piecewise constant hazard (piecewise exponential) is implemented. The methodology and examples of applying the package are detailed in <doi:10.32614/RJ-2026-009>. The Bayesian clinical trial design methodology is described in Chen et al. (2011) <doi:10.1111/j.1541-0420.2011.01561.x>, and Psioda and Ibrahim (2019) <doi:10.1093/biostatistics/kxy009>. The proportional hazards model with piecewise constant hazard is detailed in Ibrahim et al. (2001) <doi:10.1007/978-1-4757-3447-8>. Software Depends: R (>= 2.10) Imports: Rcpp, dplyr, tidyr LinkingTo: Rcpp, RcppArmadillo, RcppDist Suggests: knitr, rmarkdown, testthat (>= 3.0.0) Yueqi Shen <angieshen6@gmail.com> Comprehensive R Archive Network (CRAN) Yueqi Shen [aut, cre], Matthew A. Psioda [aut], Joseph G. Ibrahim [aut] GPL (>= 3) 2026-09-28 application/tgz https://CRAN.R-project.org/package=BayesPPDSurv doi:10.32614/CRAN.package.BayesPPDSurv