This package provides tools for fitting, diagnosing, and analyzing tie-oriented and actor-oriented relational event models, under both frequentist and Bayesian approaches. The package supports tie-oriented modeling (Butts, 2008, <doi:10.1111/j.1467-9531.2008.00203.x>) and an actor-oriented modeling framework (Stadtfeld et al., 2017, <doi:10.15195/v4.a14>), with additional model diagnostics and goodness-of-fit tools. Interfaces to estimation backends provide a range of extensions: random-effects (frailty) relational event models capturing sender, receiver, and dyadic heterogeneity (Juozaitiene & Wit 2024, <doi:10.1007/s11336-024-09952-x>; Mulder & Hoff, 2024, <doi:10.1214/24-AOAS1885>), finite mixture and dyadic latent class models for unobserved dyadic heterogeneity (Lakdawala et al., 2026, <doi:10.1016/j.socnet.2026.06.006>), penalized estimation via the lasso, ridge, and elastic net (Tibshirani, R., 1996, <doi:10.1111/j.2517-6161.1996.tb02080.x>; Karimova et al., 2023, <doi:10.1016/j.socnet.2023.02.006>), and approximate Bayesian regularization (Karimova et al., 2025, <doi:10.1016/j.jmp.2025.102925>). Modeling of events with a duration is also supported (Lakdawala et al., 2026, <doi:10.48550/arXiv.2602.21000>) and moving window relational event models (Mulder & Leenders, 2019, <doi:10.1016/j.chaos.2018.11.027>; Meijerink et al., 2023, <doi:10.1371/journal.pone.0272309>).