What endpoints are available via the public API?

Hello,

Just curious what endpoints are available through the public-api? I found preferences in addition to the available settings scan and shutdown. Curious if there are any others. 

I would like to inquire about the possibility of a couple diagnostic tools.

1) show all book covers in a single screen, so that I can figure out which ones I need to fix to display correctly in Ubooquity

2) check epubs, Not a diagnostic, but a tool to log which epubs the viewer errs when opening, so I can fix them on the back end.

Best regards.