Svelvet now have dynamic anchors as a new feature! Drag the nodes around and see what happens to the anchors!

Now you don't even need to specify sourcePosition and targetPosition in your node object anymore because Svelvet is going to take care of generating optimal anchors based on the relative posistions between two nodes.

Drag the node around and see how the anchors are changing dynamically!

Dynamic Anchors

Click here for a sandbox!