Set up a Pixi project for R — use

Create a Pixi project in the working directory, or path, if there isn't one there, and add R and rpix to it.

It sets up that folder even inside another Pixi project. If a parent folder is a Pixi project, it says so, and in an interactive session asks whether to set that one up instead.

It also adds conda-forge's conda-ecosystem-user-package-isolation, which keeps your personal R library out of the environment's R. Otherwise conda-forge's R loads packages installed for your usual R first.

It can be run from any R. Afterwards, work in R started by Pixi: run pixi run R in a terminal, or use an IDE set up with ide (see https://roald-arboel.com/rpix/articles/ide.html). Each Pixi environment has its own R and package library, so rpix doesn't point a running R at a Pixi library: packages built for a different R can crash it.

It also adds a block to the project's .Rprofile that calls pixi_activate(), so the environment is activated when an IDE starts its R directly. Projects set up with rpix 0.3.0 or earlier have a "Pixi R library setup" block in their .Rprofile instead, which pointed a running R at the Pixi library. It's removed.

A new project supports Linux, macOS (Intel and Apple Silicon) and Windows, as well as this computer's platform, so collaborators on any of them can install it. pixi.lock then covers each of them, so a package can only be added if it's on conda-forge for all of them; for one that isn't, see platform in pixi_add().

In a package, it adds .pixi, pixi.toml and pixi.lock to .Rbuildignore, so they stay out of the package's builds.

In a project that uses renv (with a renv.lock), it offers to move the packages over with pixi_import_renv() first, which also turns renv off. renv keeps rpix out of the project's own R, so run use_pixi(path = ) from another R session, e.g. your usual R outside the project.

It turns on Pixi's activation cache for the project, in .pixi/config.toml. Pixi then reuses the environment's activation until the project changes, so R started through Pixi, e.g. by pixi run or Positron, starts in a fraction of a second rather than a few. The cache is experimental in Pixi, and doesn't notice changes outside the project, e.g. a newly installed Java.

Usage

use_pixi(
  r_version = NULL,
  ide = NULL,
  init_if_missing = TRUE,
  install_rpix = TRUE,
  date = NULL,
  path = NULL,
  activation_cache = TRUE,
  platforms = NULL,
  python = FALSE,
  ...
)

Arguments

r_version: Optional. The R version to add, such as "4.5". Defaults to the newest one that conda-forge has R packages for; it has a new R before its packages are built for it.
ide: Optional. IDEs to set the project up for: any of "rstudio", "positron", "vscode", "emacs", "neovim" and "zed" (see use_pixi_ide), and "jupyter" (see use_pixi_jupyter(), experimental).
init_if_missing: If TRUE, create a Pixi project if there isn't one.
install_rpix: If TRUE, add rpix to the project (r-rpix), so it's in pixi.lock like the other packages, and a collaborator's environment has it too. Until rpix is on conda-forge, it comes from the rpix-forge channel, which is added to the project's channels after conda-forge, so everything else still comes from conda-forge. To try a change to rpix, set options(rpix.ref) to a branch, tag or commit, e.g. "main" or a pull request's branch: rpix is then also installed from GitHub, unless the environment has that commit already.
date: Optional. Use packages as they were on this date, such as "2025-06-01", e.g. to rerun an old analysis. Set before anything is added, so R and the packages are all as of that date. See pixi_set_date().
path: The folder to set up. Defaults to the working directory.
activation_cache: If TRUE, turn on Pixi's activation cache for the project.
platforms: The platforms a new project supports, besides this computer's. Defaults to "linux-64", "osx-64", "osx-arm64" and "win-64". To add platforms to an existing project, use pixi_add_platform().
python: If TRUE, add Python for reticulate, with use_pixi_python() (experimental).
...: Passed on to the IDE setup, e.g. console = "arf" for use_pixi_vscode(), or default_r = FALSE for use_pixi_positron().

Value

The path to the project's manifest, invisibly.

Examples

if (FALSE) { # \dontrun{
use_pixi()
use_pixi(r_version = "4.5", ide = "positron")
use_pixi(ide = "vscode", console = "arf")
use_pixi(date = "2025-06-01")
} # }