Two ways to build a Prism project with Codex
| Way | When it fits | What you need |
|---|---|---|
| One .tex file | A paper split into a few \input files, with figures and a .bib | The one-file .tex from Splitlight, kept in the project folder |
| A TeX installation | A thesis, a project with its own class or style files, biblatex | TeX Live (Windows, Linux), MacTeX (macOS) or MiKTeX, and latexmk |
Turning a project into one .tex
- Export the project from Prism and open the ZIP in Splitlight.
- Choose the project, then Download main.tex as one file (the name follows your main document).
- Put that file in the unzipped project folder, next to
figures/and the.bib, and open the folder in Codex.
Every \input, \include, \subfile and \import of a file in the project is pulled into the one file, between %%% begin and %%% end lines, so you can still see where each part came from. \include keeps its page break, \includeonly is honoured, and a subfile keeps only its body. Lines inside a comment or a verbatim block are left alone. A command that builds a file name from a macro cannot be followed and stays as it was; the file's first lines list anything left out.
The figures and the bibliography are still separate files. When the project uses BibTeX and the export holds the .bbl from an earlier run, the bibliography is pulled in too, which is also what many journals and arXiv ask for in a single-file submission.
Building with a TeX installation
- Install TeX Live or MacTeX (a full install is a few gigabytes), or MiKTeX on Windows.
- In the project folder run
latexmk -pdf main.tex, orlatexmk -xelatex main.texwhen Splitlight says the project needs XeLaTeX. - Compare the PDF with the last one you downloaded from Prism before you change any text.
Splitlight's check tells you, for each project, the main document, the engine it needs and why, and whether it uses BibTeX or biblatex with Biber, so the first build does not start with a guess.
What Codex does not replace
OpenAI's guide notes that Codex is not a shared real-time editor, and that Codex access and usage limits depend on your ChatGPT plan and workspace settings. If co-authors typed into the same Prism project at the same time, a web editor such as Overleaf is the closer match; here is how to move a project there.
Need one .tex for Codex? Open your Prism export here and download each document as a single file. Nothing is uploaded.
Open your export in SplitlightSplitlight Pro, $8 paid once: the whole export sorted in one ZIP, with every project ready for Overleaf, every document as one .tex, every chat as Markdown and a spreadsheet of the projects. Get Pro on Gumroad or see what is free.
Questions
Can Codex compile a Prism project?
OpenAI's migration guide says Codex's built-in LaTeX compiler is for standalone .tex files, not a complete multi-file Prism project. Turn the project into one .tex, or install TeX Live or MacTeX and build with latexmk.
How do I combine LaTeX files into one?
Replace each \input and \include with the file it names, recursively. Splitlight does this in the browser for every project in a Prism export and marks where each file begins and ends.
Does the one-file .tex include the figures?
No. Figures stay as image files next to the .tex, and the .bib too unless the export holds a BibTeX .bbl, which is pulled in.
Sources
- OpenAI Help Center: Prism to Codex migration guide (article 20001615). The export steps, export-errors.json, what does not move with the files, and the note on Codex's built-in LaTeX compiler. Read through search results and quotes, as the page refuses automated readers
- TeX Users Group: TeX Live. The TeX distribution for Windows, macOS and Linux; MacTeX is its macOS edition
- Purplelink: Move a Prism project to a Mac before it shuts down (October 25, 2026). A second reading of OpenAI's guide, by the maker of a Mac LaTeX editor
Last checked: October 30, 2026.