Check you have the following installed. NPM, NodeJS, Git.
npm --help
node --help
git --help
If you don't have any, you can get homebrew and do:
brew install npm
brew install node
Clone the github repository at https://github.com/webobservatory/wo-api-nodejs
git clone https://github.com/webobservatory/wo-api-nodejs.git
Install the required libraries using NPM and run the NodeJS app:
cd wo-api-nodejs/
npm install
cd examples/login
npm install
node app.js
Go to your browser and access http://localhost:3000