# R

> Shiny, plumber and R documents — what Toft detects, and why you need renv.lock.

Source: /toft-docs/latest/user/build/r/

| Framework | Detected by |
|---|---|
| **Shiny** | `app.R`; `ui.R` and `server.R`; `server.R` with `www/index.html`; or an `.Rmd` with `runtime: shiny` |
| **plumber** | `plumber.R`, or a root `.R` file with `#* @get`-style annotations |
| **R Markdown** | one `.Rmd` at the root, rendered at deploy time |
| **Quarto (knitr)** | one `.qmd` whose engine is knitr, rendered at deploy time |

File names match in either case (`app.r` works). The two document types are
covered in [Notebooks and documents](/toft-docs/latest/user/build/notebooks.md).

There is no generic R app: a script run with `Rscript` exits, and an app that
exits is a crash. An R repository matching none of the four is refused, with
the four listed.

## Commit `renv.lock`

> **Caution**
>
> Without `renv.lock`, no packages are installed. The deploy succeeds, the build
> log says so, and your app fails at its first `library()` call.

```r
renv::init()
renv::snapshot()
```

Commit `renv.lock`. You don't need to commit the `renv/` library.

Packages come from a repository your administrator configures. If one won't
install, the build log names it.

## Version

With no pin, Toft uses the R version recorded in `renv.lock` if the install
has it, and the default otherwise. To pin explicitly:

```toml
# toft.toml
[runtime]
r = ">=4.5"
```

Changing R versions reinstalls every package, so that deploy is slower. See
[Language versions](/toft-docs/latest/user/build/versions.md).

## From Posit Connect or RStudio

A bundle with a Posit Connect `manifest.json` and no `renv.lock` is translated
into an `renv.lock` automatically. You can also publish straight from RStudio's
**Publish** button — see [From RStudio](/toft-docs/latest/user/deploy/from-rstudio.md).