There is no public iMessage API that people can pay to use. Beeper (or rather the code it's based on) reverse-engineered the iMessage protocol and server APIs and they simply make the same requests as the iMessage app on iOS would.
This is a most excellent place for technology news and articles.
There is no public iMessage API that people can pay to use. Beeper (or rather the code it's based on) reverse-engineered the iMessage protocol and server APIs and they simply make the same requests as the iMessage app on iOS would.