The Poloniex Ruby SDK by Carl Schwope allows API interaction. It includes installation with gem & bundle. It also offers usage that demonstrates GET requests to Public API and POST requests to Trading API. Authentication required to work with Trading API.
Mastercard, a company that once warned that the risks of digital currency outweigh the benefits, has released two new blockchain APIs to promote collaboration and innovation in the digital exchange of value. Through its Mastercard Labs arm, Mastercard has indicated the API release is just the start.