For anyone who wants to understand why bobr is making a big mistake in his examples simply type the following into your browser address bar.
Code:
http://api.stripe.com
You will see the session automatically turns from a port 80 http session to a port 443 https session. In other words it defaults to SSL meaning communication to and from the API is encrypted.
Now do the same on his API
Code:
http://www.coinsbill.com/api/invoice/
The session stays on port 80 as HTTP in plain text over the Internet.
No single transaction made on his platform is secure.
Worse still - and I'm not going to post how this can be done for obvious reasons - his entire system is exposed because he has an XSS vulnerability that took me about 5 minutes to work out.
(disclaimer for tech heads: ssl & http can go over any port but in this case 80 & 443 are the ones that apply here)