Bayesian Tree Ensembles for Data Fusion and Causal Inference R package FusionForests version 1.0.1 Bayesian tree ensemble models for data fusion and causal inference. The main model FusionForest() combines data from a randomised controlled trial and an observational study using separate tree forests, allowing for unmeasured confounding in the observational data. Continuous and (interval-)censored survival outcomes are supported. Posterior summaries of treatment effect estimates and interpretable linear projections are provided. Software Depends: R (>= 3.5.0) Imports: Rcpp, ShrinkageTrees LinkingTo: Rcpp (>= 1.0.11) Suggests: survival, testthat (>= 3.0.0) Tijn Jacobs <t.jacobs@vu.nl> Comprehensive R Archive Network (CRAN) Tijn Jacobs [aut, cre] (ORCID: <https://orcid.org/0009-0003-6188-9296>) MIT + file LICENSE (https://CRAN.R-project.org/package=FusionForests/LICENSE) 2026-08-09 application/tgz https://CRAN.R-project.org/package=FusionForests doi:10.32614/CRAN.package.FusionForests