Planned removal of api_urls field in /page/summary endpoint
This message is a notice about forthcoming removal of a response field in
the REST API’s /page/summary endpoint.  This message is being cross
posted to wikitech-l and mediawiki-api-announce.
The endpoint is used in the Page Previews (“hovercards”) functionality on
the classic web (desktop) and Android & iOS experiences for Wikipedia, in
addition to numerous external experiences. We don't anticipate impacts on
the mainline Wikipedia experiences from this forthcoming field removal, as
the endpoint will still be operational.
The REST API's /page/summary endpoint provides an api_urls field in its
response with links to several other REST API endpoints supported by the
Page Content Service.
Three of the api_urls subfields refer to experimental endpoints that have
been removed from the REST API altogether in favor of newer API endpoints.
1. media (/page/media)
2. references (/page/references)
3. metadata (/page/metadata).
api_urls also contains subfields referring to stable endpoints that
continue to exist in the REST API:
1. summary (which is self referential)
2. edit_html (/page/html - the Parsoid HTML)
3. talk_html (/page/html/Talk:<title> - the Parsoid HTML for the
corresponding Talk page)
Wikimedia’s Product Infrastructure team intends to remove the api_urls
field of the /page/summary response.
Review of web logs suggests traffic for the following endpoints:
- The media endpoint is at about 5% of its original traffic before its
decommission and it appears to be from old Wikipedia for Android clients.
This is expected.
- The references endpoint’s Wikipedia for Android traffic does not seem
present and its other traffic appears to be from non-user application
software based on User-Agent header components.
-The metadata endpoint’s traffic seems to have all but stopped.
This change is being announced in advance of the change because the
endpoint is advertised as stable. 
Please update your clients if you rely on the presence of the api_urls
field. If this change poses a problem for your clients, please do let us
know as soon as possible at the tracking task: