<![CDATA[On Tags (including Hash-Tags) in ActivityPub.]]>On Tags (including Hash-Tags) in ActivityPub.

1/

I think new developers coming to ActivityPub want to write something like:

"tag": ["apple", "banana", "cherry"]

It is unfortunate that that isn't valid ActivityPub. But, that it must instead be:

"tag": [
{
"type": "Hashtag",
"name": "#apple"
},
{
"type": "Hashtag",
"name": "#banana"
},
{
"type": "Hashtag",
"name": "#cherry"
}
]

...

]]>https://bb.devnull.land/topic/4618996c-4e0d-4825-b7f6-1a95e66d2033/on-tags-including-hash-tags-in-activitypub.RSS for NodeSun, 07 Jun 2026 10:45:28 GMTTue, 19 May 2026 17:22:02 GMT60<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Thu, 21 May 2026 10:06:53 GMT]]> soooo many edge cases! 😀

]]>https://bb.devnull.land/post/https://epiktistes.com/objects/hwWo4_FuQ18https://bb.devnull.land/post/https://epiktistes.com/objects/hwWo4_FuQ18Thu, 21 May 2026 10:06:53 GMT<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Wed, 20 May 2026 15:15:24 GMT]]>> @toddsundsted@epiktistes.com said:
>
> <p><a href="/user/reiver%40mastodon.social" rel="tag">@reiver</a> i don't mind <code>type</code> but the leading hash always feels redundant</p>

haha don't worry, it's optional.

And by optional, I mean there's no specification about it, and so it's de facto part of it because Mastodon does it, but importantly, Peertube doesn't!

So you can really just do whatever you want. Omit the #, I think Mastodon and most other software handles it fine.

]]>https://bb.devnull.land/post/https://activitypub.space/post/1918https://bb.devnull.land/post/https://activitypub.space/post/1918Wed, 20 May 2026 15:15:24 GMT<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Wed, 20 May 2026 15:14:16 GMT]]>@reiver@mastodon.social hmm, I don't much mind the "type": "Hashtag" bit. Additional specificity is helpful in the long-run I think.

For example, tag contains hashtags, but it also contains mentions, "type": "Mention", so that actually makes sense.

Additional stuff that falls under the rather general name "tag" could also fit. Tagging a location, tagging an Event, etc.

This might also be what @evan was talking about, I didn't click through his link yet <img class="not-responsive emoji" src="https://activitypub.space/assets/plugins/nodebb-plugin-emoji/emoji/android/1f61c.png?v=f187f9278b7" title="😜" />

]]>https://bb.devnull.land/post/https://activitypub.space/post/1917https://bb.devnull.land/post/https://activitypub.space/post/1917Wed, 20 May 2026 15:14:16 GMT<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Wed, 20 May 2026 15:01:37 GMT]]>There's a definition for Hashtag here:

https://swicg.github.io/miscellany/#Hashtag

]]>https://bb.devnull.land/post/https://activitypub.space/post/1915https://bb.devnull.land/post/https://activitypub.space/post/1915Wed, 20 May 2026 15:01:37 GMT<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Tue, 19 May 2026 17:28:15 GMT]]> i don't mind type but the leading hash always feels redundant

]]>https://bb.devnull.land/post/https://epiktistes.com/objects/KYbr_iOBHtkhttps://bb.devnull.land/post/https://epiktistes.com/objects/KYbr_iOBHtkTue, 19 May 2026 17:28:15 GMT<![CDATA[Reply to On Tags (including Hash-Tags) in ActivityPub. on Tue, 19 May 2026 17:27:27 GMT]]>On Tags (including Hash-Tags) in ActivityPub.

2/

A new version of ActivityPub could extend the type of "tag" from:

Object | Link

to:

Object | Link | xsd:string

And that would make the following valid ActivityPub:

"tag": ["apple", "banana", "cherry"]

Of course, it would have to be specified how to interpret this. (Ex: as "type":"Hashtag", or whatever.)

]]>https://bb.devnull.land/post/https://mastodon.social/users/reiver/statuses/116602414540772845https://bb.devnull.land/post/https://mastodon.social/users/reiver/statuses/116602414540772845Tue, 19 May 2026 17:27:27 GMT