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Discover the R packages used within a project, and then install those packages into the active library. This effectively allows you to fork the state of your default R libraries for use within a project library.


  packages = NULL,
  library = NULL,
  update = FALSE,
  sources = NULL,
  project = NULL



The set of R packages to install. When NULL, the set of packages as reported by dependencies() is used.


Unused arguments, reserved for future expansion. If any arguments are matched to ..., renv will signal an error.


The R library to be hydrated. When NULL, the active library as reported by .libPaths() is used.


Boolean; should hydrate() attempt to update already-installed packages if the requested package is already installed in the project library? Set this to "all" if you'd like all packages to be refreshed from the source library if possible.


A set of library paths from which renv should attempt to draw packages. See Sources for more details.


The project directory. If NULL, then the active project will be used. If no project is currently active, then the current working directory is used instead.


A named R list, giving the packages that were used for hydration as well as the set of packages which were not found.


It may occasionally be useful to use renv::hydrate() to update the packages used within a project that has already been initialized. However, be warned that it's possible that the packages pulled in may not actually be compatible with the packages installed in the project library, so you should exercise caution when doing so.


hydrate() attempts to re-use packages already installed on your system, to avoid unnecessary attempts to download and install packages from remote sources. When NULL (the default), hydrate() will attempt to discover R packages from the following sources (in order):

  • The user library,

  • The site library,

  • The system library,

  • The renv cache.

If package is discovered in one of these locations, renv will attempt to copy or link that package into the requested library as appropriate.

Missing Packages

If renv discovers that your project depends on R packages not currently installed in your user library, then it will attempt to install those packages from the active R repositories.


if (FALSE) {

# hydrate the active library