This is very simplistic, and could be much more sophisticated. The basic extension snippet copies the selected text and creates a node with it in the current MindNode document.
# popclip
name: MNClipper
icon: M
before: copy
url: mindnode://import?format=txt&content=***
Beautiful. Simple is good ! It’s really valuable to demonstrate how powerful results can come together from quite simple concepts.
By the way, I’m not sure the before: step is needed in this case (though it does no harm). The *** will insert the selected text into the URL whether or not it is copied to clipboard.