Text messaging is fully supported within Slate. Messages may be sent on an individual basis (directly from a record or as part of communications within Inbox), en masse (through a Deliver campaign), or as part of a transactional communication associated with a form, event, or scheduler.
SMS accounts can be configured in the Deliver Configuration tool within Slate. A list of available numbers can be refined by area code, near a particular ZIP code, or contain certain digits. An institution can have any number of SMS/phone numbers - each number costs $1 per line/month.
Because of the real-world cost associated with SMS messages, credits can be purchased in order to send text messages. The full listing of service rates can be found in Deliver Configuration, however a SMS message sent/received in the United States is 1 credit (1 cent).