Yesterday, the MobileView Action API was removed from all Wikimedia production servers [1].

The API was originally built to service our apps but over time that has been replaced with the Page Content Service [2]. The original service was not being maintained, and usage was very low. If you were using the MobileView API we urge you to check this API out as it is a more powerful, better cached alternative.

We marked the API as hard deprecated in December 2019 [3], after which it was marked in ApiSandbox and in the response as deprecated, and support has been dwindling since then, for example,  the noimages parameter was dropped in September 2020 [4].

In March 2022 we removed the remaining production blocker for removing the code: language variant support [5]. The Page content service was prreviously using the mobile view API for language variant views but has now been rewired to use the better supported core action=parse API. If you need to support language variant views and previously couldn't because of the lack of support in the page content service this should no longer be an obstacle..

Since April 2022 users of the API would have been seeing an inline banning warning them of the upcoming breakage [6]. We got no feedback from these banners so were comfortable with  pushing forward.

Impact on user scripts was judged as low [7] with only 14 scripts impacted so this has not been announced on tech news.

If you are impacted by this change, I apologise that previous communications have failed you and I'd love to hear from you about how we could have done this deprecation better. If I can support you in any way in making sure your apps/gadgets/scripts are working again please feel free to reply to this email either privately or publicly or to raise a topic on the MobileFrontend talk page [8].

Finally, thanks to the engineers who helped make this deprecation possible.
Jon