I just released @codemix/graph - a fully end-to-end type-safe, real-time collaborative graph database that lives in a CRDT.

There's a demo here: https://codemix.com/graph

and it's open source on github at: https://github.com/codemix/graph

It powers the underlying knowledge graph for codemix.com - it's like an IDE for your product, not your code.