This app polls GDAX and hits a webhook whenever an order has been filled. I currently use IFTTT Maker to send iOS push notifications.
Create an IFTTT account and set up a new maker webhook https://ifttt.com/maker\_webhooks and set it up to point at something (like app notifications):
Set the notification equal to:
GDAX {{Value1}} {{Value2}}: {{Value3}}
Set in your environment:
GDAX_API_KEY=
GDAX_API_SECRET=
GDAX_API_PASS=
MAKER_EVENT=
MAKER_KEY=
Find the MAKER_KEY
from the https://ifttt.com/maker_webhooks page and click
on the "Documentation" button.
bundle exec ruby run.rb
Run under your process manager of choice.