This will annotate codeblocks with the language of the codeblock. Potentially useful for documents with multiple languages in use.

Note: The filename code chunk option won't work with this filter enabled.

Limitations: Only implemented for html output.

quarto add jofrhwld/codeblocklabel

This will install the extension under the _extensions subdirectory. If you're using version control, you will want to check in this directory.

Simply add the following to your document header.

filters:
  - codeblocklabel

This will work for both executed code blocks as well as non-executed codeblocks.

To add your own styling to the language name labels, target the langname class.

.langname {
    color: red;
}

Here is the source code for a minimal example: example.qmd.