@Hendrik Peter I'm not the author of ssb-msgs, I just sent a PR to it because I was having the same problem and could narrow it to those lines. I usually don't dive that deep into our stack rsrsrsrs.

I think I've seen a JSON Schema validation thingy/module for messages in the past but I can't remember the name now. What I do right now is not the best way. I basically use Patchfox and go to a message that is the same type as the one I want to implement, then I use the show raw message menu item and check it out. I do this a couple times to understand how the props work and then proceed to mimic them. Not the best way but I'd rather copy message structures that work than be hurt by deprecated modules or outdated documentation.

On the topic of documentation, the people in #village-tracker are doing an amazing job and most of the current advances in Patchfox can be attributed to the recent improvements in the docs.