This is the public Twilio REST API.
curl \ -u "$API_USER:$API_PASS" \ https://pricing.twilio.com/v1/Voice/Countries
curl \ -u "$API_USER:$API_PASS" \ https://pricing.twilio.com/v1/Messaging/Countries
curl \ -u "$API_USER:$API_PASS" \ https://pricing.twilio.com/v1/PhoneNumbers/Countries