Google Apps Script already has a noSQL database - scriptDB. I use it a lot, and have plenty of examples on this site. When I was developing parse.com api class for VBA , part of the motivation was that I would be able to share data across many platforms (IOS,Android,javScript etc) - including Google Apps Script. As you will know if you a regular visitor on this site, From VBA to Google Apps Script is a regular topic, and creating a GAS version of parse.com - nosql database for VBA was pretty straightforward. Since the implementation is very similar, I recommend you read up on parse.com - nosql database for VBA for concepts and getting started with Parse.
Just like in the VBA version, there is a one off authentication needed to register your credentials. Once done, you don't need to bother with them again as the API looks in your UserProperties for an encrypted version of them. For more on encryption used see this post.
The one off code you need looks like this.
In the VBA version, credentials are encrypted and stored in the Windows registry. In the GAS version, they are stored in your UserProperties. This means they are available to any script you are running, but not to libraries you are using. I'll provide the library keys for all this later, but in order to keep your credentials private, I recommend the following setup.
Something like this
Let's say you want to be able to create a a couple of parse Tables (they are called classes) from a workbook. Your script would look this, and you would include a reference to you parseCom library to make it all happen.
This would be a standalone script that would act as a gateway to the parse API, and also access your UserProperties for your parse credentials. The code in it doesn't need to be modified, just copied into a script that you own.
And here's the code to do it. You can take a copy of this script. There are also some examples there.
Before you can use your copy of parseCom, you'll need to reference the cParseCom library - here's the resource property
As described earlier, set up your credentials in your User Properties by making a private script, adding a reference to your parseCom library, entering your parse credentials and running this function,
Now you are good to go. All scripts you write will reference your parseCom library.
Here's some more detail and examples