I have an asp.net web app, where I need to develop just a UI similar to node-red drag and drop, and import/export the JSON flow, basically just a client-side functionality (HTML/CSS/Javascript) is what I need, is there any viable solution?
But that doesn't really make sense since Node-RED is BOTH back and front end code that is integrated.
However, the core of the admin UI is built using D3.js so you could use the ideas in Node-RED to build your own tool. Many visual UI tools have been built similarly.