R-universe API use cases (#1306)

Author: maelle

content/blog/2026-07-08-r-universe-api/ggsegverse.png

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+---
+title: An API for Everything There Is to Know About Packages
+author:
+  - Maëlle Salmon
+editor:
+  - Steffi LaZerte
+  - Jeroen Ooms
+date: "2026-07-08"
+slug: r-universe-apis-use-cases
+description: Use cases of the R-Universe APIs
+tags:
+  - tech notes
+  - r-universe
+  - api
+params:
+  doi: "10.59350/vrv9q-27605"
+---
+
+On R-Universe you can [discover and learn everything there is to know about R packages](/blog/2023/02/27/runiverse-discovering/). But did you know it does only provide a human-friendly website, but also programmatic access to all information through APIs! 
+Thanks to those APIs you can list universes, list packages in an universe, get information on packages, and perform searches; all without any need for authentication.
+
+The R-Universe APIs are both handy and reliable. You can build upon them, as both rOpenSci and community members have done. 
+This post shows some examples of use cases with the R-Universe API.
+
+## Know which packages are yours
+
+The toolbox for rOpenSci community management tasks, [promoutils](https://ropensci.r-universe.dev/promoutils), calls an R-Universe API to list and get information on [rOpenSci packages](https://github.com/ropensci-org/promoutils/blob/18c80362002bafe48c7c88c1ca062ac3a3050358/R/utils.R#L25). 
+This list of packages is in particular used in the [function](https://github.com/ropensci-org/promoutils/blob/18c80362002bafe48c7c88c1ca062ac3a3050358/R/help_wanted_json.R#L48) that outputs data on [help-wanted issues](/help-wanted).
+
+## Display packages developed at your organization
+
+If your organization develops R packages, you can use its R-Universe as the source of truth for your package collection. 
+For instance, the [R-Universe of ggsegverse](https://ggsegverse.r-universe.dev/builds) corresponds to, well, the ggsegverse. 
+Therefore, on the ggsegverse website, the [listing of packages](https://ggsegverse.github.io/ecosystem/) is created by querying `https://ggsegverse.r-universe.dev/api/packages`, the endpoint for [information on all packages in the universe](https://docs.r-universe.dev/browse/api.html#information-of-all-packages-in-an-universe).
+
+{{< figure src="ggsegverse.png" alt="Screenshot of the ggsegverse website, with informative package cards" link="https://ggsegverse.github.io/ecosystem/" >}}
+
+Likewise, the [docs page](https://ggsegverse.github.io/docs/) of ggsegverse relies on the R-Universe API to retrieve links to vignettes for each package.
+
+### Server-side or client-side API requests
+
+The ggsegverse website performs **client-side requests**: it queries the R-Universe API when you open the webpage, through a [JS script](https://github.com/ggsegverse/ggsegverse.github.io/blob/aea3723f885387ca9399408ccfbcc7a1ec9d7820/js/api.js). 
+You can also check this through the [web developer tools](https://inspectelement.org/apis.html#how-to-find-and-use-undocumented-apis):
+
+{{< figure src="request.png" alt="Screenshot of the web developer tools' network tab, showing the XHR request logged when one reloads the ggsegverse website" >}}
+
+The rendering of the nice package cards happens through [another JS script](https://github.com/ggsegverse/ggsegverse.github.io/blob/fec52718432d098b1162772f3f94985a1d0feef3/js/render.js) that uses information such as the package's title, description, number of stars, etc.
+
+In contrast, for package listings on author and package pages, the rOpenSci website uses **server-side requests**: the API is called when Hugo renders our website. 
+For instance, for the list of packages at the bottom of [Jeroen Ooms' author page](/author/jeroen-ooms/), we [query](https://github.com/ropensci/roweb3/blob/503f0547854925eaa72a0e2c36420e3731e98ebf/themes/ropensci/layouts/author/list.html#L84) the R-Universe API link from our website [configuration](https://github.com/ropensci/roweb3/blob/7851904c5297868b7c372788166c526f2fe2ed1d/config.toml#L60) and [filter](https://github.com/ropensci/roweb3/blob/503f0547854925eaa72a0e2c36420e3731e98ebf/themes/ropensci/layouts/author/list.html#L85) the packages by GitHub login.
+
+{{< figure src="jeroen.png" alt="Screenshot of Jeroen Ooms' author page on the rOpenSci website, featuring the list of rOpenSci packages that he maintains." >}}
+
+On a Quarto website, you could have a code chunk using R to query the R-Universe APIs, through the [universe R package](https://docs.ropensci.org/universe/) for instance.
+
+In any case, if you use server-side requests, you need to re-render your website regularly to avoid your packages' listing to get out-of-date. 
+The nice thing about client-side requests is that the package lists will be always up-to-date!
+
+## Search Packages
+
+With R-universe, you can search packages, not only through the web interface but also through an [API](https://docs.r-universe.dev/browse/api.html#api-global-search).
+
+The project [The Wharehouse](https://rwarehouse.netlify.app/), that helps users find packages according to given keywords, [uses R-universe as one its information sources](https://rwarehouse.netlify.app/about#resources-credits).
+
+## Conclusion
+
+In this post we provided some use cases of the R-Universe APIs. 
+Try them out, or read the [docs](https://docs.r-universe.dev/browse/api.html) to get a sense of all the information that's shared through the different endpoints. 
+If you maintain some infrastructure that uses an R-Universe API, feel free to report a [use case](/usecases)!
+