cffr cffr website
CRAN-status CRAN-results Downloads R-CMD-check codecov r-universe CITATION-cff DOI Project Status: Active - The project has reached a stable, usable state and is being actively developed. GitHub code size in bytes peer-review
cffr provides utilities to generate, coerce, modify, and validate
CITATION.cff files automatically for R packages, along with tools
and examples for working with .cff files more generally.
Citation File Format (CFF) (Druskat et al. 2021) (v1.2.0) are plain text files with human- and machine-readable citation information for software (and datasets). Code developers can include them in their repositories to let others know how to correctly cite their software.
This format is gaining popularity within the software citation ecosystem. Recently, GitHub, Zenodo, and Zotero have fully supported this citation format (Druskat 2021). GitHub support is of special interest:
Tweet of Nat Friedman about CFF files
— Nat Friedman (@natfriedman) July 27, 2021
See Enhanced support for citations on GitHub (Smith 2021) for more information.
The CodeMeta Project (Jones et al.
2017) creates a concept vocabulary that can be used to
standardize the exchange of software metadata across repositories and
organizations. One of the many uses of a codemeta.json file (created
following the standards defined by The CodeMeta Project) is to provide
citation metadata such as title, authors, publication year, and venue
(Fenner 2021). The packages codemeta (Boettiger
and Salmon 2021) and codemetar (Boettiger and
Salmon 2026) allow for generating codemeta.json
files from R package metadata.
cffr maximizes data extraction by utilizing both the DESCRIPTION
file and the CITATION file (if present) from your package. Note that
cffr works best if your package passes
R CMD check/devtools::check().
As per 2026年02月17日 there are at least 486 repos on GitHub using cffr. Check them out here.
Install cffr from CRAN:
install.packages("cffr")You can install the developing version of cffr with:
remotes::install_github("ropensci/cffr")
Alternatively, you can install cffr using the r-universe:
# Install cffr in R: install.packages( "cffr", repos = c("https://ropensci.r-universe.dev", "https://cloud.r-project.org") )
Most commonly, from within your package folder, you’ll simply run
cff_write(), which creates a cff object, writes it to a
CITATION.cff file, and validates it in a single command:
library(cffr) # For in-development packages cff_write() #> #> CITATION.cff generated #> #> cff_validate results----- #> Congratulations! This .cff file is valid
However, cffr provides also custom print methods and mechanisms that
allows you to customize the CITATION.cff and integrate them in your
workflows.
This is a basic example which shows you how to create a cff object
(see ?cff for more info). In this case, we are creating a cff object
from the metadata of the rmarkdown package:
library(cffr) # Example with an installed package test <- cff_create("knitr")
CITATION.cff for knitr
CITATION.cff for knitrcff-version: 1.2.0
message: 'To cite package "knitr" in publications use:'
type: software
license: GPL-1.0-only
title: 'knitr: A General-Purpose Package for Dynamic Report Generation in R'
version: '1.51'
identifiers:
- type: doi
value: 10.32614/CRAN.package.knitr
abstract: Provides a general-purpose tool for dynamic report generation in R using
Literate Programming techniques.
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
preferred-citation:
type: manual
title: 'knitr: A General-Purpose Package for Dynamic Report Generation in R'
authors:
- family-names: Xie
given-names: Yihui
orcid: https://orcid.org/0000-0003-0645-5666
email: xie@yihui.name
year: '2025'
notes: R package version 1.51
url: https://yihui.org/knitr/
repository: https://CRAN.R-project.org/package=knitr
repository-code: https://github.com/yihui/knitr
url: https://yihui.org/knitr/
date-released: '2025-12-20'
contact:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
keywords:
- dynamic-documents
- knitr
- literate-programming
- r
- r-package
- rmarkdown
- sweave
references:
- type: book
title: Dynamic Documents with R and knitr
authors:
- family-names: Xie
given-names: Yihui
publisher:
name: Chapman and Hall/CRC
address: Boca Raton, Florida
year: '2015'
edition: 2nd
notes: ISBN 978-1498716963
url: https://yihui.org/knitr/
- type: generic
title: 'knitr: A Comprehensive Tool for Reproducible Research in R'
authors:
- family-names: Xie
given-names: Yihui
collection-title: Implementing Reproducible Computational Research
collection-type: collection
editors:
- family-names: Stodden
given-names: Victoria
- family-names: Leisch
given-names: Friedrich
- family-names: Peng
given-names: Roger D.
publisher:
name: Chapman and Hall/CRC
year: '2014'
notes: ISBN 978-1466561595
- type: software
title: 'R: A Language and Environment for Statistical Computing'
notes: Depends
url: https://www.R-project.org/
authors:
- name: R Core Team
institution:
name: R Foundation for Statistical Computing
address: Vienna, Austria
year: '2026'
version: '>= 3.6.0'
- type: software
title: evaluate
abstract: 'evaluate: Parsing and Evaluation Tools that Provide More Details than
the Default'
notes: Imports
url: https://evaluate.r-lib.org/
repository: https://CRAN.R-project.org/package=evaluate
authors:
- family-names: Wickham
given-names: Hadley
email: hadley@posit.co
- family-names: Xie
given-names: Yihui
orcid: https://orcid.org/0000-0003-0645-5666
year: '2026'
doi: 10.32614/CRAN.package.evaluate
version: '>= 0.15'
- type: software
title: highr
abstract: 'highr: Syntax Highlighting for R Source Code'
notes: Imports
url: https://github.com/yihui/highr
repository: https://CRAN.R-project.org/package=highr
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
- family-names: Qiu
given-names: Yixuan
year: '2026'
doi: 10.32614/CRAN.package.highr
version: '>= 0.11'
- type: software
title: methods
abstract: 'R: A Language and Environment for Statistical Computing'
notes: Imports
authors:
- name: R Core Team
institution:
name: R Foundation for Statistical Computing
address: Vienna, Austria
year: '2026'
- type: software
title: tools
abstract: 'R: A Language and Environment for Statistical Computing'
notes: Imports
authors:
- name: R Core Team
institution:
name: R Foundation for Statistical Computing
address: Vienna, Austria
year: '2026'
- type: software
title: xfun
abstract: 'xfun: Supporting Functions for Packages Maintained by ''Yihui Xie'''
notes: Imports
url: https://github.com/yihui/xfun
repository: https://CRAN.R-project.org/package=xfun
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
year: '2026'
doi: 10.32614/CRAN.package.xfun
version: '>= 0.52'
- type: software
title: yaml
abstract: 'yaml: Methods to Convert R Data to YAML and Back'
notes: Imports
url: https://yaml.r-lib.org
repository: https://CRAN.R-project.org/package=yaml
authors:
- family-names: Stephens
given-names: Jeremy
- family-names: Simonov
given-names: Kirill
year: '2026'
doi: 10.32614/CRAN.package.yaml
version: '>= 2.1.19'
- type: software
title: bslib
abstract: 'bslib: Custom ''Bootstrap'' ''Sass'' Themes for ''shiny'' and ''rmarkdown'''
notes: Suggests
url: https://rstudio.github.io/bslib/
repository: https://CRAN.R-project.org/package=bslib
authors:
- family-names: Sievert
given-names: Carson
email: carson@posit.co
orcid: https://orcid.org/0000-0002-4958-2844
- family-names: Cheng
given-names: Joe
email: joe@posit.co
- family-names: Aden-Buie
given-names: Garrick
email: garrick@posit.co
orcid: https://orcid.org/0000-0002-7111-0077
year: '2026'
doi: 10.32614/CRAN.package.bslib
- type: software
title: DBI
abstract: 'DBI: R Database Interface'
notes: Suggests
url: https://dbi.r-dbi.org
repository: https://CRAN.R-project.org/package=DBI
authors:
- name: R Special Interest Group on Databases (R-SIG-DB)
- family-names: Wickham
given-names: Hadley
- family-names: Müller
given-names: Kirill
email: kirill@cynkra.com
orcid: https://orcid.org/0000-0002-1416-3412
year: '2026'
doi: 10.32614/CRAN.package.DBI
version: '>= 0.4-1'
- type: software
title: digest
abstract: 'digest: Create Compact Hash Digests of R Objects'
notes: Suggests
url: https://eddelbuettel.github.io/digest/
repository: https://CRAN.R-project.org/package=digest
authors:
- family-names: Eddelbuettel
given-names: Dirk
email: edd@debian.org
orcid: https://orcid.org/0000-0001-6419-907X
year: '2026'
doi: 10.32614/CRAN.package.digest
- type: software
title: gifski
abstract: 'gifski: Highest Quality GIF Encoder'
notes: Suggests
url: https://r-rust.r-universe.dev/gifski
repository: https://CRAN.R-project.org/package=gifski
authors:
- family-names: Ooms
given-names: Jeroen
email: jeroenooms@gmail.com
orcid: https://orcid.org/0000-0002-4035-0289
- name: Kornel Lesiński
- name: Authors of the dependency Rust crates
year: '2026'
doi: 10.32614/CRAN.package.gifski
- type: software
title: htmlwidgets
abstract: 'htmlwidgets: HTML Widgets for R'
notes: Suggests
url: https://github.com/ramnathv/htmlwidgets
repository: https://CRAN.R-project.org/package=htmlwidgets
authors:
- family-names: Vaidyanathan
given-names: Ramnath
- family-names: Xie
given-names: Yihui
- family-names: Allaire
given-names: JJ
- family-names: Cheng
given-names: Joe
email: joe@posit.co
- family-names: Sievert
given-names: Carson
email: carson@posit.co
orcid: https://orcid.org/0000-0002-4958-2844
- family-names: Russell
given-names: Kenton
year: '2026'
doi: 10.32614/CRAN.package.htmlwidgets
version: '>= 0.7'
- type: software
title: jpeg
abstract: 'jpeg: Read and write JPEG images'
notes: Suggests
url: https://www.rforge.net/jpeg/
repository: https://CRAN.R-project.org/package=jpeg
authors:
- family-names: Urbanek
given-names: Simon
email: Simon.Urbanek@r-project.org
orcid: https://orcid.org/0000-0003-2297-1732
year: '2026'
doi: 10.32614/CRAN.package.jpeg
- type: software
title: magick
abstract: 'magick: Advanced Graphics and Image-Processing in R'
notes: Suggests
url: https://docs.ropensci.org/magick/
repository: https://CRAN.R-project.org/package=magick
authors:
- family-names: Ooms
given-names: Jeroen
email: jeroenooms@gmail.com
orcid: https://orcid.org/0000-0002-4035-0289
year: '2026'
doi: 10.32614/CRAN.package.magick
- type: software
title: litedown
abstract: 'litedown: A Lightweight Version of R Markdown'
notes: Suggests
url: https://github.com/yihui/litedown
repository: https://CRAN.R-project.org/package=litedown
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
year: '2026'
doi: 10.32614/CRAN.package.litedown
- type: software
title: markdown
abstract: 'markdown: Render Markdown with ''commonmark'''
notes: Suggests
url: https://github.com/rstudio/markdown
repository: https://CRAN.R-project.org/package=markdown
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
- family-names: Allaire
given-names: JJ
- family-names: Horner
given-names: Jeffrey
year: '2026'
doi: 10.32614/CRAN.package.markdown
version: '>= 1.3'
- type: software
title: otel
abstract: 'otel: OpenTelemetry R API'
notes: Suggests
url: https://otel.r-lib.org
repository: https://CRAN.R-project.org/package=otel
authors:
- family-names: Csárdi
given-names: Gábor
email: csardi.gabor@gmail.com
year: '2026'
doi: 10.32614/CRAN.package.otel
- type: software
title: otelsdk
abstract: 'otelsdk: ''R'' ''SDK'' and Exporters for ''OpenTelemetry'''
notes: Suggests
url: https://otelsdk.r-lib.org
repository: https://CRAN.R-project.org/package=otelsdk
authors:
- family-names: Csárdi
given-names: Gábor
email: csardi.gabor@gmail.com
year: '2026'
doi: 10.32614/CRAN.package.otelsdk
- type: software
title: png
abstract: 'png: Read and write PNG images'
notes: Suggests
url: http://www.rforge.net/png/
repository: https://CRAN.R-project.org/package=png
authors:
- family-names: Urbanek
given-names: Simon
email: Simon.Urbanek@r-project.org
year: '2026'
doi: 10.32614/CRAN.package.png
- type: software
title: ragg
abstract: 'ragg: Graphic Devices Based on AGG'
notes: Suggests
url: https://ragg.r-lib.org
repository: https://CRAN.R-project.org/package=ragg
authors:
- family-names: Pedersen
given-names: Thomas Lin
email: thomas.pedersen@posit.co
orcid: https://orcid.org/0000-0002-5147-4711
- family-names: Shemanarev
given-names: Maxim
year: '2026'
doi: 10.32614/CRAN.package.ragg
- type: software
title: rlang
abstract: 'rlang: Functions for Base Types and Core R and ''Tidyverse'' Features'
notes: Suggests
url: https://rlang.r-lib.org
repository: https://CRAN.R-project.org/package=rlang
authors:
- family-names: Henry
given-names: Lionel
email: lionel@posit.co
- family-names: Wickham
given-names: Hadley
email: hadley@posit.co
year: '2026'
doi: 10.32614/CRAN.package.rlang
- type: software
title: rmarkdown
abstract: 'rmarkdown: Dynamic Documents for R'
notes: Suggests
url: https://pkgs.rstudio.com/rmarkdown/
repository: https://CRAN.R-project.org/package=rmarkdown
authors:
- family-names: Allaire
given-names: JJ
email: jj@posit.co
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
- family-names: Dervieux
given-names: Christophe
email: cderv@posit.co
orcid: https://orcid.org/0000-0003-4474-2498
- family-names: McPherson
given-names: Jonathan
email: jonathan@posit.co
- family-names: Luraschi
given-names: Javier
- family-names: Ushey
given-names: Kevin
email: kevin@posit.co
- family-names: Atkins
given-names: Aron
email: aron@posit.co
- family-names: Wickham
given-names: Hadley
email: hadley@posit.co
- family-names: Cheng
given-names: Joe
email: joe@posit.co
- family-names: Chang
given-names: Winston
email: winston@posit.co
- family-names: Iannone
given-names: Richard
email: rich@posit.co
orcid: https://orcid.org/0000-0003-3925-190X
year: '2026'
doi: 10.32614/CRAN.package.rmarkdown
- type: software
title: sass
abstract: 'sass: Syntactically Awesome Style Sheets (''Sass'')'
notes: Suggests
url: https://rstudio.github.io/sass/
repository: https://CRAN.R-project.org/package=sass
authors:
- family-names: Cheng
given-names: Joe
email: joe@rstudio.com
- family-names: Mastny
given-names: Timothy
email: tim.mastny@gmail.com
- family-names: Iannone
given-names: Richard
email: rich@rstudio.com
orcid: https://orcid.org/0000-0003-3925-190X
- family-names: Schloerke
given-names: Barret
email: barret@rstudio.com
orcid: https://orcid.org/0000-0001-9986-114X
- family-names: Sievert
given-names: Carson
email: carson@rstudio.com
orcid: https://orcid.org/0000-0002-4958-2844
year: '2026'
doi: 10.32614/CRAN.package.sass
- type: software
title: showtext
abstract: 'showtext: Using Fonts More Easily in R Graphs'
notes: Suggests
url: https://github.com/yixuan/showtext
repository: https://CRAN.R-project.org/package=showtext
authors:
- family-names: Qiu
given-names: Yixuan
- family-names: details.
given-names: authors/contributors of the included software. See file AUTHORS for
year: '2026'
doi: 10.32614/CRAN.package.showtext
- type: software
title: styler
abstract: 'styler: Non-Invasive Pretty Printing of R Code'
notes: Suggests
url: https://styler.r-lib.org
repository: https://CRAN.R-project.org/package=styler
authors:
- family-names: Müller
given-names: Kirill
email: kirill@cynkra.com
orcid: https://orcid.org/0000-0002-1416-3412
- family-names: Walthert
given-names: Lorenz
email: lorenz.walthert@icloud.com
- family-names: Patil
given-names: Indrajeet
email: patilindrajeet.science@gmail.com
orcid: https://orcid.org/0000-0003-1995-6531
year: '2026'
doi: 10.32614/CRAN.package.styler
version: '>= 1.2.0'
- type: software
title: tibble
abstract: 'tibble: Simple Data Frames'
notes: Suggests
url: https://tibble.tidyverse.org/
repository: https://CRAN.R-project.org/package=tibble
authors:
- family-names: Müller
given-names: Kirill
email: kirill@cynkra.com
orcid: https://orcid.org/0000-0002-1416-3412
- family-names: Wickham
given-names: Hadley
email: hadley@rstudio.com
year: '2026'
doi: 10.32614/CRAN.package.tibble
- type: software
title: tinytex
abstract: 'tinytex: Helper Functions to Install and Maintain TeX Live, and Compile
LaTeX Documents'
notes: Suggests
url: https://github.com/rstudio/tinytex
repository: https://CRAN.R-project.org/package=tinytex
authors:
- family-names: Xie
given-names: Yihui
email: xie@yihui.name
orcid: https://orcid.org/0000-0003-0645-5666
year: '2026'
doi: 10.32614/CRAN.package.tinytex
version: '>= 0.56'
- type: software
title: rstudioapi
abstract: 'rstudioapi: Safely Access the RStudio API'
notes: Suggests
url: https://rstudio.github.io/rstudioapi/
repository: https://CRAN.R-project.org/package=rstudioapi
authors:
- family-names: Ushey
given-names: Kevin
email: kevin@rstudio.com
- family-names: Allaire
given-names: JJ
email: jj@posit.co
- family-names: Wickham
given-names: Hadley
email: hadley@posit.co
- family-names: Ritchie
given-names: Gary
email: gary@posit.co
year: '2026'
doi: 10.32614/CRAN.package.rstudioapi
- type: software
title: svglite
abstract: 'svglite: An ''SVG'' Graphics Device'
notes: Suggests
url: https://svglite.r-lib.org
repository: https://CRAN.R-project.org/package=svglite
authors:
- family-names: Wickham
given-names: Hadley
email: hadley@posit.co
- family-names: Henry
given-names: Lionel
email: lionel@posit.co
- family-names: Pedersen
given-names: Thomas Lin
email: thomas.pedersen@posit.co
orcid: https://orcid.org/0000-0002-5147-4711
- family-names: Luciani
given-names: T Jake
email: jake@apache.org
- family-names: Decorde
given-names: Matthieu
email: matthieu.decorde@ens-lyon.fr
- family-names: Lise
given-names: Vaudor
email: lise.vaudor@ens-lyon.fr
year: '2026'
doi: 10.32614/CRAN.package.svglite
We can validate the result using cff_validate():
cff_validate(test) #> ══ Validating cff ══════════════════════════════════════════════════════════════
Check the docs
and vignette("cffr", package = "cffr") to learn how to work with cff
objects.
The easiest way to keep your CITATION.cff file up-to-date is using
GitHub Actions. Use cff_gha_update() function to install a GitHub
Action that will update your CITATION.cff file on the following
events:
- When you publish a new release of the package on your GitHub repo.
- Each time that you modify your DESCRIPTION or inst/CITATION files.
- The action can be run also manually.
cff_gha_update() #> ✔ Installing ./.github/workflows/update-citation-cff.yml #> i Adding ".github" to .Rbuildignore
See the example workflow file here.
Git pre-commit hook Experimental
You can also use a git pre-commit hook:
The
pre-commithook is run first, before you even type in a commit message. It’s used to inspect the snapshot that’s about to be committed, to see if you’ve forgotten something, to make sure tests run, or to examine whatever you need to inspect in the code. Exiting non-zero from this hook aborts the need to inspect in the code. Exiting non-zero from this hook aborts the commit, although you can bypass it withgit commit --no-verify.
A specific pre-commit hook can be installed with
cff_git_hook_install(). If you want to use a pre-commit hook, please
make sure you have the testthat package installed.
Check the following articles to learn more about cffr:
- cffr: Create a CITATION.cff File for your R Package
- How I Test cffr on (about) 2,000 Packages using GitHub Actions and R-universe
- citation (Dietrich and Leoncio 2025) includes a
function
r2cffthat creates aCITATION.cfffile (v1.1.0) using the information of yourDESCRIPTIONfile. It also provide minimal validity checks. - handlr (Chamberlain and Wiernik 2025): Tool for
converting among citation formats, including
*.cfffiles. - codemeta (Boettiger and Salmon 2021) /
codemetar (Boettiger and Salmon 2026)
provides similar solutions for creating
codemeta.jsonfile, another format for storing and sharing software metadata.
Please note that the cffr project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.
Hernangómez, D., (2021). cffr: Generate Citation File Format Metadata for R Packages. Journal of Open Source Software, 6(67), 3900, https://doi.org/10.21105/joss.03900
A BibTeX entry for LaTeX users is:
@article{hernangomez2021, title = {{cffr}: Generate Citation File Format Metadata for {R} Packages}, author = {Diego Hernangómez}, year = 2021, journal = {Journal of Open Source Software}, publisher = {The Open Journal}, volume = 6, number = 67, pages = 3900, doi = {10.21105/joss.03900}, url = {https://doi.org/10.21105/joss.03900} }
You can also use the citation provided by
GitHub, that is generated from the
information of a CITATION.cff created with cffr. See About
CITATION
files
for more info.
Boettiger, Carl, and Maëlle Salmon. 2021. codemeta: A Smaller codemetar Package. https://doi.org/10.32614/CRAN.package.codemeta.
———. 2026. codemetar: Generate ’CodeMeta’ Metadata for R Packages. https://doi.org/10.32614/CRAN.package.codemetar.
Chamberlain, Scott, and Brenton M. Wiernik. 2025. handlr: Convert Among Citation Formats. https://doi.org/10.32614/CRAN.package.handlr.
Dietrich, Jan Philipp, and Waldir Leoncio. 2025. citation: Software Citation Tools. https://doi.org/10.32614/CRAN.package.citation.
Druskat, Stephan. 2021. "Making Software Citation Easi(er) - The Citation File Format and Its Integrations." https://doi.org/10.5281/zenodo.5529914.
Druskat, Stephan, Jurriaan H. Spaaks, Neil Chue Hong, Robert Haines, James Baker, Spencer Bliven, Egon Willighagen, David Pérez-Suárez, and Alexander Konovalov. 2021. "Citation File Format." https://doi.org/10.5281/zenodo.5171937.
Fenner, Martin. 2021. "We Need Your Feedback: Aligning the CodeMeta Vocabulary for Scientific Software with Schema.org." https://doi.org/10.5438/a49j-x692.
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