TL;DR: The legacy Mobile Content Service is going away in July 2023. Please switch to Parsoid or another API before then to ensure service continuity.
I'm writing about a service decommission we hope to complete mid-July 2023. The service to be decommissioned is the legacy Mobile Content Service ("MCS"), which is maintained by the Wikimedia Foundation's Content Transform Team. We will be marking this service as deprecated soon.
We hope that with this notice, people will have ample time to update their systems for use of other endpoints such as Parsoid [1] (n.b., MCS uses Parsoid HTML).
The MCS endpoints are the ones with the relative URL path pattern /page/mobile-sections* on the Wikipedias. For examples of the URLs see the "Mobile" section on the online Swagger (OpenAPI) specification documentation with matching URLs here:
https://en.wikipedia.org/api/rest_v1/#/Mobile== History ==
The Mobile Content Service ("MCS") is the historical aggregate service that originally provided support for the article reading experience on the Wikipedia for Android native app, as well as some other experiences. We have noticed that there are other users of the service. We are not able to determine all of the users, as it's hard to tell with confidence from the web logs.
The Wikimedia Foundation had already transitioned the Wikipedia for Android and iOS apps to the newer Page Content Service ("PCS") several years ago. PCS has some similarities with MCS in terms of its mobility focus, but it also has different request-response signatures in practice. PCS, as with MCS, is intended to primarily satisfy Wikimedia Foundation-maintained user experiences only, and so this is classified with the "unstable" moniker.
== Looking ahead ==
Generally, as noted in the lead, we recommend that folks who use MCS (or PCS, for that matter) switch over to Parsoid for accessing Wikipedia article content programmatically for the most predictable service.
The HTML produced by Parsoid has a versioned specification [2] and because Parsoid is accessed regularly by a number of components across the globe tends to have fairly well cached responses. However, please note that Parsoid may be subject to stricter rate limits that can apply under certain traffic patterns.
At this point, I do also want to note that in order to keep up with contemporary HTML standards, particularly those favoring accessibility and machine readability enhancements, Parsoid HTML will undergo change as we further converge parsing stacks [3]. Generally, you should expect iteration on the Parsoid HTML spec, and of course as you may have come to appreciate that the shape of HTML in practice can vary nontrivially wiki-by-wiki as practices across wikis vary.
You may also want to consider Wikimedia Enterprise API options, which range from no cost to higher volume access paid options.
https://meta.wikimedia.org/wiki/Wikimedia_Enterprise#Access== Forking okay, but not recommended ==
Because MCS acts as a service aggregate and makes multiple backend API calls, caveats can apply for those subresources - possibility of API changes, deprecation, and the like. We do not recommend a plain fork of MCS code because of the subresource fetch behavior. This said, of course you are welcome to fork in a way compatible with MCS's license.
== Help spread the word ==
Although we are aware of the top two remaining consumers of MCS, we also are not sure who else is accessing MCS and anticipate that some downstream tech may break when MCS is turned off. As we are cross-posting this message, we hope most people who have come to rely upon MCS will see this message. Please feel free to forward this message to contacts if you know they are using MCS.
== Help ==
Although we intend to decommission MCS in July 2023, we would like to share resources if you need some help. We plan to hold office hours in case you would like to meet with us to discuss this or other Content Transform Team matters. We will host these events on Google Meet. We will provide notice of these office hours on the wikitech-l mailing list in the coming weeks and months.
Additionally, if you would like to discuss your MCS transition plans, please visit the Content Transform Team talk page:
https://www.mediawiki.org/wiki/Talk:Content_Transform_TeamFinally, some Content Transform Team members will also be at the Wikimedia Hackathon [4] if you would like some in-person support.
Thank you.
Adam Baso (he/him/his/Adam), on behalf of the Content Transform Team
Director of Engineering
Wikimedia Foundation
[1]
https://www.mediawiki.org/wiki/Parsoid[2]
https://www.mediawiki.org/wiki/Specs/HTML[3]
https://www.mediawiki.org/wiki/Parsoid/Parser_Unification/Updates[4]
https://www.mediawiki.org/wiki/Wikimedia_Hackathon_2023