"Edit: isn’t this super costly for personal use?"

Not really ... I notice twilio deducting USD $9 every 10 or 12 days ? It's a business expense.

I also 'lookup' numbers to check if they are mobile or not:

  curl -s -X GET "https://lookups.twilio.com/v1/PhoneNumbers/$number?Type=carrier&Type=caller-name" -u $accountsid:$authtoken | /usr/local/bin/jq '.'

... which is handy. Usually shows their name and carrier ID as well.

As you can see, I pipe it through 'jq' because that's what all the cool kids do.