Joris,
Whose repository are you using? The one from Conner (cdcharlebois) is probably your best bet. Then there are a few other things required:
Thanks all for the help.
I've got it running now and just some tweaking and debugging to do with cancel actions from users so it has a fallback.
Things I had to do adjust at the code from Conner:
Thanks all for the help!
Joris
To me, this doesn't sound right at all: node.js is used for server side JavaScript (and additionally, you don't compile JavaScript). You are running a Mendix server, not a node.js server.
To use mobile device functionality (and I am assuming that getting a fingerprint is device functionality), you should create a Mendix widget which utilizes Cordova functions to access this functionality.
Then, you should override the Mendix login functionality to accept output of the fingerprint scanner and verify that output and the PIN.
you could try to integrate a third party api solution with youre app. take a look at onegini for example