In 2008, Google enabled an API for Webmaster Tools, since then they've been adding functionality to it slowly.
But this morning, Google announced they completely overhauled it on the backend, moving it to the format other Google APIs are in, which brings consistently and the ability for Google to add more features to it more quickly.
I believe some of the old features are not supported, yet, in the new API but Google makes it sound like they will be added soon and more will come.
Google's John Mueller said on Google+:
The bulk of the work was moving to this new infrastructure, so future updates should be a bit easier.
John did poll SEOs and webmasters back in April about what updates they wanted to see to the API.
The current API allows for:
- list, add, or remove sites from your account (you can currently have up to 500 sites in your account)
- list, add, or remove sitemaps for your websites
- get warning, error, and indexed counts for individual sitemaps
- get a time-series of all kinds of crawl errors for your site
- list crawl error samples for specific types of errors
- mark individual crawl errors as "fixed" (this doesn't change how they're processed, but can help simplify the UI for you)
