Thread:Talk:Requests for comment/API Future/Versioning and removed features

More often than not, breaking changes that we make to the API are because we have to, and thus it would be impossible to have a previous version that supports old ways. For example, when action=login was changed, it was for security reasons - hence we wouldn't be able to have a versioned api with the old version as we can't be insecure in a previous version of the api. I'm sure quite a few other breaking changes were performance related (schema changes and what not) which we also would not be able to expose in an "old" version of the API.

There are certainly a few things that would be nice to change. Personally I don't like how action=watch returns a UI msg, there's a bunch of deprecated parameters to action=edit and a few other modules, etc. However, these are generally few and far between (and also not overly hurting people) as far as I can tell (Although I'm not all that familiar with deprecation and the API so may be wrong).