Probably need a new source : XE is blocking this

[moeadham]

Requests from XE.com are returning as:

[richardtan]

Yup, I forked the code and used https://currencylayer.com/ free API. It gives access to 1000 calls, so use use a cron job to poll it every hour and store all the currencies in the Google Datastore and use that to interface with the currencies. Hope that gives you some idea :)