CmdStanR is a lightweight interface to Stan for R users (see CmdStanPy for Python).

If you are new to CmdStanR we recommend starting with these vignettes:


  • A clean interface to Stan services so that CmdStanR can keep up with Stan releases.

  • R code that doesn’t interface directly with C++, only calls compiled executables.

  • Modularity: CmdStanR runs Stan’s algorithms and lets downstream modules do the analysis.

  • Flexible BSD-3 license.


Installing the R package

You can install the latest beta release of the cmdstanr R package with

# we recommend running this is a fresh R session or restarting your current session
install.packages("cmdstanr", repos = c("https://stan-dev.r-universe.dev", getOption("repos")))

This does not install the vignettes, which take a long time to build, but they are always available online at https://mc-stan.org/cmdstanr/articles/.

To instead install the latest development version of the package from GitHub use

# install.packages("remotes")

Installing CmdStan

If you don’t already have CmdStan installed then, in addition to installing the R package, it is also necessary to install CmdStan using CmdStanR’s install_cmdstan() function. A suitable C++ toolchain is also required. Instructions are provided in the Getting started with CmdStanR vignette.


There is a lot of work still to be done and we welcome contributions from anyone! If you are interested in contributing please comment on an open issue or open a new one if none are applicable.


CmdStanR, like CmdStan and the core Stan C++ code, is licensed under the following licenses: