Can InputRules work for NodeView Leaf Nodes?

Hi, i’m creating a NodeView that has content in it but I want to save that content outside of the editor since it would add complexity to my project. This means that I plan to create a node without content in it.

I would still like for certain plugins and features such as inputRules to work and I am wondering if it is possible to use input rules in this use case.

No, that probably isn’t possible. In general, I do recommend keeping content in the ProseMirror document (it makes things like collaborative editing of that content a lot easier, and avoids having to sync between the document and an external data source), but in some circumstances I guess your approach is indeed preferable.