How to create a hidden node property

[ralphwetzel]

@Colin

it is for an existing contrib node

You don't have to make this detour - if your intension was just to add a manifest.json for your contrib node. Take the manifest the plugin created as template, modify it to your demands & drop it in the directory next to your standard Node-RED files.

It will be found there by the plugin and injected / utilized as necessary.
And if you defined the preload option, your contrib node will of course be preloaded ... !