Step 1 :
Login to Dashboard ( www.cognalys.com/customer/login ) 
Go to Settings -> Web API settings 
Grab your API
You will see the YOUR_API_KEY .  REGISTERED_EMAIL_ID and API KEY  is used to authenticate API . 
Example :
https://www.cognalys.com/rest/api/v1/apps/?username=REGISTERED_EMAIL_ID&api_key=YOUR_API_KEY&format=json
format ( defaults to json ) :
We supports Serializations like
- xml
 - plist
 - jsonp
 - json
 
u may change eg : format=xml
 If above link is authenticated you will get the return JSON . If not server will return a blank page