Hello! Well, the account itself is free of charge and gives you access to API that you can review. Sending messages is something we charge for, no matter the channel (API/Portal).

is the api going to be free for real or i will pay in some form

Hello! You need to create an account at SMSAPI.com. First four steps of the tutorial, that I have written will guide you. You could skip step 2 if you would like to just test stuff.

Good luck!
Jakub