While not strictly required, it is heavily encouraged to have it installed due to events that Clumps fires for mod compat.

I would rather have it listed as a required dependency compared to dealing with issues saying that the mod compat doesn't work.

Thanks for the explanation. Searchables also has it listed as required despite being in recommends; am I right to assume that's for the same reason? And did you mean to have it as recommends in Clumps too, but forgot?

Searchables actually has no reason to depend on Fabric API, I always add the fabric api when I start developing projects due to it being required for even the most basic thing such as loading resources, however in that mod's case I guess it isn't required at all.

As for the Fabric Mod Json, I don't have an answer for you there, it isn't something I usually spend too much time on when developing, so it is very likely that I just copied the file from another project and went to code the actual mod.

It should probably have fabric api in the recommends