User-Editable R Functions in 'Shiny' Apps with a Step Debugger R package shinyStep version 0.5.1 A pair of 'Shiny' modules that let end users of a 'Shiny' application author their own R functions directly in the browser. Host apps can expose these modules as extension points where user-supplied code augments or replaces built-in logic, without requiring users to modify the app's source. Each module embeds an 'Ace' editor with a structured argument table, an in-frame R console rooted in the paused function's local environment, and a step debugger that handles for, while, repeat, and if/else blocks at any nesting depth. Two module flavours are provided: solo editors for testing a function in isolation with literal argument values, and embedded editors for pausing a function mid-execution inside a larger host program. Software Imports: shiny (>= 1.7.0), shinyAce (>= 0.4.0) Suggests: testthat (>= 3.0.0) Han Zhang <zhangh.ustc@gmail.com> Comprehensive R Archive Network (CRAN) Han Zhang [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=shinyStep/LICENSE) 2026-05-29 application/tgz https://CRAN.R-project.org/package=shinyStep doi:10.32614/CRAN.package.shinyStep