Continued my experiments with #Fedify and #ActivityPub yesterday and I think I’m confused.

[pablo@sivar.cafe]

Continued my experiments with #Fedify and #ActivityPub yesterday and I think I’m confused.

I was trying to make an extension for an Object, and if I understand #JsonLd, the context property contains the definition of any extra property added. I see e.g. the activity streams ns resolves to a nice JSON LD that contains all the properties, but the mastodon one doesn’t resolve to anything? Is it not necessary?

[pablo@sivar.cafe]

If I add a random domain to it, the fedify lookup command fails trying to resolve it… but the mastodon one failing to resolve seems to be ok?

[hongminhee@fosstodon.org]

@pablo Not all ActivityPub implementations process JSON-LD properly. Rather, the situation is the other way around: the most of ActivityPub implementations treat Activity Streams objects as plain JSON objects.

[pablo@sivar.cafe]

@hongminhee ah that explains a lot. So I'm guessing adding proper context values is, in practice, more of a common courtesy for documentation rather than a technical necessity?

[hongminhee@fosstodon.org]

@pablo Yes, for the most part; but for Fedify which relies on proper JSON-LD processor, it's actually necessary.

[pablo@sivar.cafe]

@hongminhee Thanks! Is this only for the cli?

Does it make an exception for known extensions (e.g. Mastodon)? (Or maybe there’s something I’m not seeing?)

[hongminhee@fosstodon.org]

@pablo No, it's applied to any software built with Fedify, e.g., Hollo.

Many implementations just ignore @context, and look at bare property names (e.g., votersCount, not toot:votersCount).