write out a codemeta.json file for a given package. This function is basically a wrapper around create_codemeta() to both create the codemeta object and write it out to a JSON-LD-formatted file in one command. It can also be used simply to write out to JSON-LD any existing object created with create_codemeta().

  pkg = ".",
  path = "codemeta.json",
  root = ".",
  id = NULL,
  use_filesize = TRUE,
  force_update = getOption("codemeta_force_update", TRUE),
  use_git_hook = NULL,
  verbose = TRUE,
  write_minimeta = FALSE,



package path to package root, or package name, or description file (character), or a codemeta object (list)


file name of the output, leave at default "codemeta.json"


if pkg is a codemeta object, optionally give the path to package root. Default guess is current dir.


identifier for the package, e.g. a DOI (or other resolvable URL)


whether to try to estimating and adding a filesize by using base::file.size(). Files in .Rbuildignore are ignored.


Update guessed fields even if they are defined in an existing codemeta.json file


Deprecated argument.


Whether to print messages indicating opinions e.g. when DESCRIPTION has no URL. -- See give_opinions; and indicating the progress of internet downloads.


whether to also create the file schemaorg.json that corresponds to the metadata Google would validate, to be inserted to a webpage for SEO. It is saved as "inst/schemaorg.json" alongside path (by default, "codemeta.json").


additional arguments to write_json


writes out the codemeta.json file, and schemaorg.json if write_codemeta is TRUE.


Why bother creating a codemeta.json for your package? R packages encode lots of metadata in the DESCRIPTION file, README, and other places, telling users and developers about the package purpose, authors, license, dependencies, and other information that facilitates discovery, adoption, and credit for your software. Unfortunately, because each software language records this metadata in a different format, that information is hard for search engines, software repositories, and other developers to find and integrate.

By generating a codemeta.json file, you turn your metadata into a format that can easily crosswalk between metadata in many other software languages. CodeMeta is built on schema.org a simple structured data format developed by major search engines like Google and Bing to improve discoverability in search. CodeMeta is also understood by significant software archiving efforts such as Software Heritage Project, which seeks to permanently archive all open source software.

For more general information about the CodeMeta Project for defining software metadata, see https://codemeta.github.io. In particular, new users might want to start with the User Guide, while those looking to learn more about JSON-LD and consuming existing codemeta files should see the Developer Guide.

How to keep codemeta.json up-to-date? In particular, how to keep it up to date with DESCRIPTION? codemetar itself no longer supports automatic sync, but there are quite a few methods available out there. Choose one that fits well into your workflow!

  • You could rely on devtools::release() since it will ask you whether you updated codemeta.json when such a file exists.

  • You could use a git pre-commit hook that prevents a commit from being done if DESCRIPTION is newer than codemeta.json.

    • You can use the precommit package in which there’s a “codemeta-description-updated” hook.

    • If that’s your only pre-commit hook (i.e. you don’t have one created by e.g. usethis::use_readme_rmd()), then you can create it using

script = readLines(system.file("templates", "description-codemetajson-pre-commit.sh", package = "codemetar"))
                     script = script)

  • You could use GitHub actions. Refer to GitHub actions docs https://github.com/features/actions, and to the example workflow provided in this package (type system.file("templates", "codemeta-github-actions.yml", package = "codemetar")). You can use the cm-skip keyword in your commit message if you don’t want this to run on a specific commit. The example workflow provided is setup to only run when a push is made to the master branch. This setup is designed for if you’re using a git flow setup where the master branch is only committed and pushed to via pull requests. After each PR merge (and the completion of this GitHub action), your master branch will always be up to date and so long as you don’t make manual changes to the codemeta.json file, you won’t have merge conflicts.

Alternatively, you can have GitHub actions route run codemetar on each commit. If you do this you should try to remember to run git pull before making any new changes on your local project. However, if you forgot to pull and already committed new changes, fret not, you can use (git pull --rebase) to rewind you local changes on top of the current upstream HEAD.

click here to see the workflow

    branches: master
      - .github/workflows/main.yml

name: Render codemeta
    name: Render codemeta
    runs-on: macOS-latest
    if: "!contains(github.event.head_commit.message, 'cm-skip')"
      - uses: actions/[email protected]
      - uses: r-lib/actions/[email protected]
      - name: Install codemetar
        run: Rscript -e 'install.packages("codemetar")'
      - name: Render codemeta
        run: Rscript -e 'codemetar::write_codemeta()'
      - name: Commit results
        run: |
          git commit codemeta.json -m 'Re-build codemeta.json' || echo "No changes to commit"
          git push https://${{github.actor}}:${{secrets.GITHUB_TOKEN}}@github.com/${{github.repository}}.git HEAD:${{ github.ref }} || echo "No changes to commit"

Technical details

If pkg is a codemeta object, the function will attempt to update any fields it can guess (i.e. from the DESCRIPTION file), overwriting any existing data in that block. In this case, the package root directory should be the current working directory.

When creating and writing a codemeta.json for the first time, the function adds "codemeta.json" to .Rbuildignore.


# \donttest{ codemeta <- tempfile() write_codemeta("codemetar", path = codemeta)
#> … Getting sysreqs URL from sysreqs API #> ✔ Got sysreqs URL from sysreqs API! #> … Asking README URL from GitHub API #> ✔ Got README URL! #> … Asking README URL from GitHub API #> ✔ Got README URL! #> … Getting repo topics from GitHub API #> ✔ Got repo topics!
# }