Handle marimo tex components when exporting to PDF

[Light2Dark]

📝 Summary

Fix LaTeX rendering in ipynb/PDF exports by converting marimo's internal <marimo-tex> HTML format back to standard $...$ / $$...$$ delimiters.

\[...\] → $$...$$ conversion is also implemented but disabled. However, it seems nbconvert/jupyter doesn't handle them jupyter/nbconvert#477.

Example cell-output

[{'output_type': 'display_data', 'metadata': {}, 
  'data': {'text/markdown': '<span class="markdown prose dark:prose-invert contents">
  <span class="paragraph">The exponential function 
  <marimo-tex class="arithmatex">||(f(x) = e^x||)</marimo-tex> can be represented as</span></span>'}
}]

🔍 Description of Changes

We wrap LaTeX in custom tags with ||(...) delimiters (via pymdownx.arithmatex). The frontend renders these with KaTeX, but nbconvert doesn't understand them, causing broken math in exports.

Not included

• mhchem support (\ce{H2O}) - I think would require custom nbconvert LaTeX template. https://stackoverflow.com/questions/30203791/converting-ipython-notebook-mhchem-markdown-to-pdf

📋 Checklist

• I have read the contributor guidelines.
• For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on Discord, or the community discussions (Please provide a link if applicable).
• Tests have been added for the changes made.
• Documentation has been updated where applicable, including docstrings for API changes.
• Pull request title is a good summary of the changes - it will be used in the release notes.

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview, Comment	Feb 3, 2026 7:14pm

[dmadisetti]

Nice. But we're not converting \[ notation? A little confused, if jupyter doesn't support it, then we should convert right?

[dmadisetti]

For a sanity check, can you convert this to our markdown format too?

[dmadisetti]

Yeah, I see a natural ask being to include .sty and .cls files for things like mhchem support and other libraries. But maybe we can cross that bridge when we get there

[Light2Dark]

Nice. But we're not converting \[ notation? A little confused, if jupyter doesn't support it, then we should convert right?

They don't support rendering this syntax afaik. And nbconvert doesn't support parsing this syntax either hence raises an error. So, we are altering the code we send to nbconvert to make it work. From my understanding, \[ is basically escaping a bracket and hence treated like normal markdown. This issue jupyter/nbconvert#477 and consequent PR attempts to add more parsing for nbconvert but was rejected.

I don't really know what the state is now, maybe use jupyter with this extension? https://github.com/jfbercher/jupyter_latex_envs

[Light2Dark]

@dmadisetti I think I'm okay to support it. My worry was false positives but the regex looks right. Also seems like it's the recommended way to write LaTeX now.

[mscolnick]

i assume this syntax error was intentional. but typo is re-writing it? we can create a different syntax error

[Light2Dark]

addressed in the pre-commit PR, but yeah, that's also possible lol