oauth module to retrive an access token with google service account


Wanted to accesss my personal calendar, NOT the one of Google Apps, and found no good example for node.js with service account without any interaction.

npm install google-oauth-serviceaccount
  1. Create your service account and enable calendar access(thanks to this post):
>    a) Log in into the Google account you want to use to manage your projects.
>    b) Go to
>    c) Create a project. You will get issued a project number, in our example
>    we'll use 99999999999.
>    d) Allow the project to use the calendar API:
>    -> services (left pane), then find 'calendar api' and set the button 'on'
>    e) Create a Service Account.
>    -> API access (left pane); select 'create service account'
>    Part of the procedure is that you'll get a PKCS#12 bundle, which you can
>    download and should store on your appserver in a secure location. Your
>    app should be able to access it, but outsiders should not be allowed to
>    download it.
2. Store the p12 file into pem with openssl(thank [this][2])
$ openssl pkcs12 -in yourkey.p12 -out yourkey.pem -nodes<br/>
type "notasecret" for password.
  1. Share the calendar with your developer account

    Calendar "Settings" -> "Share this calendar", at "Share with specific people", put the email address of developer account choosing a permission you want, then "add person". The address should be like "".

  2. Edit oahtu-config.json and place key.pem which generated in step 2.

     "keyFile": "key.pem"
    ,"expiresInMinuteas": 60
  1. Test with test.js.

    if successfull, you'll see an access token:


  2. Enjoy with calendar APIs. You may try listEvents.js.

const request = require('request');
const gaccount = require('./google-oauth-serviceaccount');
const calRoot = "";
    var token = "?access_token="+access_token;
        }, function(errresbody){
            for(var c=0; c<body.items.length; c++){
                    }, function(errrescal){