The AssertEdit extension has long been installed on WMF wikis, allowing bots to include "&assert=user" or "&assert=bot" in their action=edit requests to prevent accidentally editing while logged out.

With Gerrit change 90263,[1] the functionality will be included in MediaWiki core. At the same time, the following changes will be made to the functioning of this feature: * Assertion will be available on all API actions, not just edit. * Assertion failure will now be indicated by an API error, code 'assertbotfailed' or 'assertuserfailed'. * The 'nassert' parameter will be ignored, and using it will give an unrecognized parameter warning. * Other assertions, such as 'true', 'false', and 'exists', will no longer function and attempting to use them will result in an 'unknown_assert' error.

Most clients should notice little change from this transition besides the fact of receiving an error rather than a failure status from action=edit.

This change will be rolled out with 1.23wmf10, see https://www.mediawiki.org/wiki/MediaWiki_1.23/Roadmap for the schedule.

[1]: https://gerrit.wikimedia.org/r/#/c/90263/