Expanding the Compendium

Hi, am I able to make extensions to the compendium. For example if I build a homebrew class, item etc. can i somehow add this so my players can just use drag and drop with my homebrew stuff just as if it would be official stuff? Civer 

Unfortunately no, that's not possible. Many of us would like a similar feature too.

When compendiums were first added to Roll20 the dev team did indeed express a keen interest in eventually adding customisation options and/or personal compendiums for systems not currently covered. Their main concern was perfecting the current compendium system and ensuring the security of compendium data to prevent (inadvertent or deliberate) copyright infringements. As with all things, something on this scale is bound to take time but there are those amongst us (myself included) who hope it is still a future feature! I'd like to think that the recent compendium sharing feature for GMs to share purchased content with their players is a step in this direction :)

There are some limited  options with API scripts, particularly ChatSetAttr, but they require a LOT of prep work.