Status: The MediaWiki API is a mature and stable interface that is actively supported and improved. While we try to avoid it, we may occasionally need to make breaking changes; subscribe to the mediawiki-api-announce mailing list for notice of updates.
Erroneous requests: When erroneous requests are sent to the API, an HTTP header will be sent with the key "MediaWiki-API-Error" and then both the value of the header and the error code sent back will be set to the same value. For more information see API: Errors and warnings.
Testing: For ease of testing API requests, see Special:ApiSandbox.