I'm trying to find primary sources in medieval Occitan. Are there any letters, documents etc. in Occitan ideally available online? I'm interested in the 14th century, but would be happy about pointers to any accessible sources.
Did you search the Bibliotheque Nationale listings online?
There are a lot of French sites with stuff on the troubadors, of course , here is a site with some lyrics left in Occitan/Provencal.