This module is in npm as askwatson. It provides a simple API for asking Watson a question on Bluemix using the question_and_answer service.

Basically you will need to get set up on Bluemix/CF and follow the instructions given for the sample Node.js application here https://www.ibm.com/smarterplanet/us/en/ibmwatson/developercloud/doc/qaapi/#commonApplication, including running the cf commands, but I have factored out that code a bit into two modules, so your application can be cleaner. In case you need help finding the cf command line program you can download it from here https://github.com/cloudfoundry/cli/releases (under Installers) and install it with dpkg -i <filename>.

The first module is called bluemix-request-simple and it has the parts for pulling the host and port out of the environment and using them in a request.

The other module is this one, which is very simple to use:

watson.ask('healthcare', 'What is the most common kind of cancer', function(err, answers) {
  console.log(answers);
});

This will need to run on Bluemix so a more complete example would be:

var watson = require('askwatson')
  , restify = require('restify');

var server = restify.createServer();

server.get('/:domain/:question', function(req, res) {
  watson.ask(req.params.domain, req.params.question, function(e, ans) {
    res.send(ans);
  });    
});

server.listen(process.env.VCAP_APP_PORT, process.env.VCAP_APP_HOST, function() {
  console.log('%s listening at %s', server.name, server.url);
});

Note that if you use GET as in this example it will be simpler to test but you can only use short questions (try curl "http://whatever.mybluemix.net/healthcare/What+is+the+most+common+kind+of+cancer"). If you use something longer for the question it will blow up the app, so you will probably want to use POST.