Hameed,
This lists more generic documentation about certain Platform SDK end-points and resources:
https://docuware-online.com/DocuWare/Platform/Documentation
And this lists resource URLs to perform operations and links to various request/response structures for XML and JSON:
https://docuware-online.com/DocuWare/Platform/Home/UriTemplatesDocumentation
Some of those areas include curl examples, which should be fairly easy to translate into JavaScript calls. I have never seen mention of a full-on wrapper for anything Java or JavaScript-based. I assumed that was because it is relatively easy to make HTTP-based requests from those environments. Authentication is a bit tricky (due to not being very well documented), but links further down explain all that, too.
For more in-depth support, I am guessing DocuWare will tell you that you need to purchase specific Platform SDK support. That's what I was told when I asked about using the Platform Services from a non-.NET environment (we use Visual Foxpro). On that front, here are a couple links to forum posts about all that (including authentication):
https://www.docuware.com/forum/english-forums/docuware-help-technical-problems/platform-sdk-urls-and-serverxmlhttp-object
https://www.docuware.com/forum/english-forums/docuware-help-technical-problems/using-platform-sdk-other-dev-tools
The XMLHTTP object built into Windows internet API stack (we switched to that from ServerXMLHTTP) is just a wrapper on HTTP requests and responses that you should be able to mimic in node.js. All of my code is in Visual Foxpro, which probably looks ugly to the non-Foxpro eye, but it is fairly straightforward to get the gist of it.
Good luck!
Joe Kaufman