Thanks everyone who advised on Zinc, REST, NeoJSON, HMAC & Libsodium to help me on my way to implement an interface to the Bittrex bitcoin exchange. I've got to the point where I'm happy to make an initial 0.x release. After all my years having fun hacking around Pharo, this is my first (tiny) product. Hopefully it may grow. :) The implementation is probably closest to a Command pattern with a class per entry-point. All the v1.1 entry points are implemented except a few to deposit & withdraw money from the exchange. These are currently infrequent events for me and left for manual action. I'm optimistic that I'll add a few more exchanges so I created a github org to group them together. Contributions welcome. Please see quick start instructions here... https://github.com/Traadh/bittrex Have fun and take care... https://imgs.xkcd.com/comics/engineer_syllogism.png cheers -ben