In an interesting and useful turn of events, GDAX has announced it is releasing open source trading tools.
The GDAX trading toolkit
The GTT is designed to act as a set of Lego blocks to help you build automated trading and portfolio bots on crypto-currency exchanges. Here are the kinds of things we envisage you could build with a few hundred lines of code using the GTT:
This seems to be a way for Coinbase/GDax to encourage use of it's exchange. GDax is one of the only truly regulated exchanges out there.