xero-quickstart

main.js

var consumer_key = '...';
var request = require('request').defaults({
  oauth: {
    consumer_key: consumer_key,
    token: consumer_key,
    signature_method : 'RSA-SHA1',
    private_key: require('fs').readFileSync('privatekey.pem')
  },
  json: true
});
request('https://api.xero.com/api.xro/2.0/Organisation', function(e, r, organisation) {
  console.log(e || organisation);
});

package.json

{
  "name": "xero-quickstart",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "request": "^2.72.0"
  }
}

privatekey.pem

-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----