Twilio API (SMS and Voice, SG numbers)

How to authenticate

1. 1Sign up at twilio.com; trial account works immediately with verified numbers.
2. 2Copy Account SID and Auth Token from the console (or create API keys).
3. 3For SG alphanumeric sender IDs, register via Twilio per SGNIC/IMDA rules (mandatory since 2023, otherwise SMS shows LIKELY-SCAM).
4. 4Send requests with HTTP Basic auth (SID as username, token as password).

Example request

curl -X POST 'https://api.twilio.com/2010-04-01/Accounts/ACXXXX/Messages.json' -u ACXXXX:AUTH_TOKEN -d 'To=+65XXXXXXXX' -d 'From=SENDER_ID' -d 'Body=Your OTP is 123456'

Example response

{"sid":"SMXXXXXXXX","status":"queued","to":"+65XXXXXXXX","from":"SENDERID","body":"Your OTP is 123456"}