I AM NOT A FAN OF THIS IN ANY WAY, SHAPE, OR FORM.
I pay for Obsidian Sync because it is secure and it works way better than any of the other sync services (provided it is setup properly - iCloud, G Drive, Onedrive, and Dropbox… are not your friends when using Obsidian Sync).
You can get at blocks and tags and most any content in your vault via the standard API on your LOCAL vault. Even the core search plugin allows for all of this and there are numerous ways to automate that. And, since most of you asking for this are developers, create your own private plugin to do what your are requesting.
THERE IS A REASON WHY THIS WILL NEVER BE DONE - and if it is, most of us would stop using Obsidian Sync immediately and be way more LOUDER about it than the few of you in this post.
Making a public interface to secure sync service… are you folks aware of what you’re asking for in this post?