R

This page covers the requirements and internals of deploying R content to ricochet.

Project requirements

Every R deployment requires a renv.lock file in the project root. This lockfile is generated by {renv} and records all package dependencies and their versions.

Example `_ricochet.toml`

[content]
name = "My Shiny App"
entrypoint = "app.R"
access_type = "external"
content_type = "shiny"

[language]
name = "r"
packages = "renv.lock"

[serve]
min_instances = 0
max_instances = 5

Supported content types

R content items can be deployed as apps or tasks.

Apps

`Content Type`	Description
`plumber`	An API developed using `{plumber}`.
`ambiorix`	An API or web app developed using `{ambiorix}`.
`shiny`	A web app developed using `{shiny}`.
`rmd-shiny`	An R Markdown document using a Shiny runtime.
`quarto-r-shiny`	A Quarto document using a Shiny runtime.
`serverless-r`	R functions deployed as an API.
`r-service`	A generic web app or API using an R runtime.

Tasks

`Content Type`	Description
`r`	An R script with the extension `.R` or `.r`.
`rmd`	An R Markdown document. Can be served as a static site.
`quarto-r`	A Quarto document using an R runtime. Can be served as a static site.

How ricochet runs R content

R version discovery

Ricochet discovers R installations on the host machine. We recommend installing R versions via rig for the best experience managing multiple versions:

rig add <version>

You can also install R from CRAN or your distribution’s package manager.

Environment restoration

Ricochet vendors renv at $RICOCHET_HOME/vendor. When a bundle is deployed, ricochet restores R package dependencies from the renv.lock file using the vendored renv.

Out-of-sync lockfile

A deployment shows Out of sync when renv.lock does not match the packages your project uses. Update the lockfile in your project and redeploy:

# list the packages that differ from renv.lock
renv::status()
# record the project library in renv.lock
renv::snapshot()

The badge appears in one of two situations:

The restore failed, so the deployment status is Out of sync and a task cannot run until you redeploy.
The restore succeeded but reported drift, such as a package that is installed but not recorded in renv.lock.

In the second case your content runs, and hovering the badge shows the message with a link to the matching lines of the restore log.

A server running a different R version than the one recorded in renv.lock does not count as drift.