I am glad that someone else shares the idea that it should be possible to set tags manually.

Here is a list of API actions which need to be able to set tags:

• action=wbcreateclaim
• action=wbcreateredirect
• action=wbeditentity
• action=wblinktitles
• action=wbmergeitems
• action=wbremoveclaims
• action=wbremovequalifiers
• action=wbremovereferences
• action=wbsetaliases
• action=wbsetclaim
• action=wbsetclaimvalue
• action=wbsetdescription
• action=wbsetlabel
• action=wbsetqualifier
• action=wbsetreference
• action=wbsetsitelink

Makes sense to me.
Do other modules outside Wikibase already allow it?

See the linked task.

There currently seem to be at least two workarounds for this missing feature:

• an AbuseFilter that matches on the edit summary and adds the tag
• [a gadget that uses action=tag to tag its edit after it has been made](https://ru.wikipedia.org/wiki/MediaWiki:Gadget-wikidataInfoboxExport.js)

@darthmon_wmde I’ve already started working on this (as part of Wikidata Bridge task T227003), so I’m not sure it makes much sense to unassign me…

To clarify: for Wikidata Bridge we likely only need support in wbeditentity, but the most reasonable implementation (as far as I can tell) ends up adding support to almost all other modules as well. The exception are modules that create a redirect rather than a regular entity edit – I’ll leave those aside for now. (Also, I’m not implementing this for modules outside of Wikibase, i. e. WikibaseLexeme.)

Change 528221 had a related patch set uploaded (by Lucas Werkmeister (WMDE); owner: Lucas Werkmeister (WMDE)):
[mediawiki/extensions/WikibaseLexeme@master] Add $tags parameter to {Form,Sense}Store::saveEntity()

https://gerrit.wikimedia.org/r/528221

Change 528222 had a related patch set uploaded (by Lucas Werkmeister (WMDE); owner: Lucas Werkmeister (WMDE)):
[mediawiki/extensions/Wikibase@master] Add $tags parameter to EntityStore, EditEntity

https://gerrit.wikimedia.org/r/528222

Change 528223 had a related patch set uploaded (by Lucas Werkmeister (WMDE); owner: Lucas Werkmeister (WMDE)):
[mediawiki/extensions/Wikibase@master] Add tags parameter to editing API modules

https://gerrit.wikimedia.org/r/528223

Actually, let’s split this task up after all. Disregard the gerritbot comments, I’ll move those patches to one of the subtasks.

We have added a few recently as part of the work to tag all edits made through the UI. Is there anything missing still? If yes can we clarify what exactly is missing?

@Lydia_Pintscher I'm not sure if this is the point of this ticket but: I am trying to add a tag when performing wbcreateclaim and get the following error:
​​

code: "badtags"
disallowedtags:
  - "Wikidata for Firefox 🦊" 
info: 'The tag "Wikidata for Firefox 🦊" is not allowed to be manually applied.'
​​

Is this not how tags should be used? what should I do?

The tag must be valid. Your tag is not supported. The list of supported tags is on https://www.wikidata.org/wiki/Special:Tags.
If you need the tag for an application, request it on https://www.wikidata.org/wiki/Wikidata:Administrators%27_noticeboard.

Note that support in one of the remaining APIs, wblinktitles, is needed for a Content Translation feature (T335256).

@Ifrahkhanyaree_WMDE: If I understand correctly, maintenance of the Action API is within the scope of Wikibase Reuse Team; do you plan to implement this?

We just spoke about this in our call but just so we have it in written - we're not planning to work on it anytime soon and we're hoping to clarify the next steps regarding Action API/REST API within the next few weeks