WRITE: SENDS REAL SMS to real people and SPENDS the prepaid balance of the user's Notifyre account; it cannot be undone or recalled and is never retried. One text to 1 to 10 mobile numbers in international format with "+" (e.g. +61412345678); no contacts, no groups, no scheduling. Cost = price per message part (see notifyre_list_sms_prices; it depends on the destination country) x number of parts x number of recipients; the text may be up to 640 characters (160 per part, 70 with emoji or non-GSM characters, a little less per part when it is longer). Only send what the user explicitly asked for: confirm the exact text, the recipients and the sender first. Recipients must have agreed to receive messages. A commercial SMS needs an opt-out (Australia: Spam Act 2003; Notifyre Terms and Conditions 13.5): set add_unsubscribe_link true to append Notifyre's opt-out link, or put your own opt-out instruction in the text. The default is false, so the requirement is yours to meet. US numbers need a registered 10DLC campaign. Omit from to send from a Notifyre shared number. An unclear result (timeout, HTTP 5xx) means the message may still have been sent: check notifyre_list_sent_sms before trying again. Notifyre API: POST /sms/send.