I made a patch for the first part:

• https://gerrit.wikimedia.org/r/348110 Show supported data formats in Special:EntityData

For the second part, it's not easily doable. Unless we inject Output or Context to EntityDataRequestHandler which I don't think it would be a good idea and it would be lots of overhead just to make it happen in a hacky way.

In T162870#3179567, @Ladsgroup wrote:

I made a patch for the first part:

• https://gerrit.wikimedia.org/r/348110 Show supported data formats in Special:EntityData

For the second part, it's not easily doable. Unless we inject Output or Context to EntityDataRequestHandler which I don't think it would be a good idea and it would be lots of overhead just to make it happen in a hacky way.

Thanks for your help, @Ladsgroup!

If the second point isn't possible, linking a page that shows the available formats would be enough (for example, Special:EntityData after your patch).

Change 348110 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Show supported data formats in Special:EntityData

https://gerrit.wikimedia.org/r/348110

Change 349397 merged by jenkins-bot:
[mediawiki/extensions/Wikibase@master] Change Assert type from regex to simple when there is no need

https://gerrit.wikimedia.org/r/349397