Google has completely revamped the Google Merchant Center API help document page. It was previously named "API access to Merchant Center" and was renamed to "Google Merchant Center API." Plus, the content on the page has been completely rewritten and expanded.
The old version made no mention of older tools or broader architecture. The new version has a lot more detail on the specific technical options. The old version had no setup or authentication instructions. The new version also highlights the benefits and exclusive features, such as Google Product Studio and direct account notifications. And plenty of other changes.
Here is a diff of the two documents - old and new:
Forum discussion at X.
