The API is taking data from Nucleon threat intelligence service.

Nucleon is collecting & analysing data from thousands of hacker attacks on computers all around the world.
among other things Nucleon is also keeping a list of the passwords that have been tried during attacks.
This API gives you an option to add additional security to your own login process by calling the API and verify
whether password is known to be used by hackers or not.

The API is very simple, it accept a password as parameter and returns json response if the password was found or not.
If the password was found the service also returns the score of the password, the score is composed of a number,
the higher the number the more common this password is by hackers.

** Remember this API is only checking for known passwords that Nucleon encountered before ,
it doesn’t say whether your password is weak or not **