Which fonts can Tectonic download automatically

I am trying to understand Tectonic’s logic of how it finds and downloads fonts. In the Tectonic book, there is the example

  Extension = .otf,
  UprightFont = *-regular,
  BoldFont = *-bold,
  ItalicFont = *-italic,
  BoldItalicFont = *-bolditalic,

When running this, the font is automatically downloaded and used. I tried to use other open source fonts, however I always end up with an error that the font cannot be found. So I started wondering:

  • Are there only certain fonts (for example from a some specific source) that can automatically be found? Is there a list available?
  • If the mechanism should work more generally, what is the naming scheme to adhere to?

Unfortunately I don’t have a direct answer to your question, but I’m not sure yet why you think this is a problem with Tectonic.
If you didn’t check that yet, please try to compile such an example with an other compiler to double check you have your font names correct.

If it works with, say, xelatex but not with Tectonic, please file a github issue. (You’d need to install the fonts yourself first, of course)
If it doesn’t work with xelatex either, it is probably a good idea to read more about how fonts are found, in my experience it’s not very intuitive.

Thank you. I don’t actually see any issue with Tectonic itself. Using fontspec and locally available fonts works completely as expected. I would like to integrate the Tectonic binary into another program and make use of the feature that it downloads packages etc. automatically. With the example cited in my original post, the font gets fetched automatically. My question was simply if there are other fonts available where this happens as well, so that I don’t have to bundle them with the rest of the program.

Ah, if you want to integrate it into a different program that makes the question indeed different. I still don’t know an answer though, if you put a short question on Issues · tectonic-typesetting/tectonic · GitHub you might get some answers.

I tried to use other open source fonts

Are you sure you only tried fonts that are available in LaTeX packages?

Look for a font here:

Look for a similar line in “Usage” on a fonts page, e.g.:
\usepackage[usefilenames,DefaultFeatures={Ligatures=Common}]{plex-otf} %

Put this Line in the LATEX_HEADER keyword, eg.:
#+LATEX_HEADER: \usepackage[usefilenames,DefaultFeatures={Ligatures=Common}]{plex-otf} %