Hello, folks.
As you all must know, the API is considered a beta feature. It had changes several times in the past, but there isn't a public changelog for us to keep track of what's going on. That being the case, I'll try to keep a list of API changes in this post, with especial attention to the breaking ones -- these will be marked as red.
2016-05-31 - BACKWARDS INCOMPATIBLE
/user/?selections=messages: from property changed to ID, name property added
/user/?selections=messages,events: timestamp query parameter added - it's a time filter (newer than)
If you file a bug report or feature request that results in a backward incompatible change, I'd appreciate if you replied to this thread so it's bumped and I can edit the list. Please, keep the conversation to a minimum, so that bumps are mostly relevant notices.