gistfile1.txt

var request  = require('request')
  , qs = request('querystring')
  , modhash
  , cookie;

function postComment () {
  var parentId = 't1_cf9k3wa'
    , options = {
        url      : 'https://api.reddit.com/api/comment',
        headers  : {
            'User-Agent' : 'foobot/0.1 by username',
            'X-Modhash'  : modhash,
            'Cookie' : cookie
          },
        method : 'POST',
        body : qs.stringify({
            api_type : 'json',
            text : 'foobar',
            thing_id : parentId
          })
      };

  request(options, function (err, res, body) {
    if (err) {
      console.log(err);
      return;
    } else {
      console.log('// ------ //');

      console.log(res);
      console.log(body);

      console.log('// ------ //');
    }
  });
}

function login () {
  var options = {
      url     : 'https://ssl.reddit.com/api/login?api_type=json&user=username&passwd=password&rem=True',
      headers : {
        'User-Agent' : 'foobot/0.1 by username'
      },
      method  : 'POST'
  };

  request(options, function (err, res, body) {
    if (err) {
      console.log(err.json.errors);
      return;
    } else {
      var parsedBody = JSON.parse(body);
      console.log('// ------ //');

      console.log(parsedBody.json.data.modhash);
      console.log(parsedBody.json.data.cookie);
      console.log(parsedBody.json.data);

      modhash = parsedBody.json.data.modhash;
      cookie  = parsedBody.json.data.cookie;
    }
  });
}