SKILL.md
Overview
SMS is one channel in Twilio's Messaging platform. All channels — SMS, WhatsApp, RCS, Facebook Messenger — share the same messages.create() API. See twilio-messaging-overview for the full channel comparison and onboarding sequence.
| When to use SMS | When to consider alternatives |
|---|---|
| Reach any phone number globally | Need rich media outside US/CA/AU → WhatsApp |
| No app install required | Opted-in audience prefers chat apps → WhatsApp |
| Time-sensitive alerts (OTP, outage) | Marketing campaigns → twilio-marketing-promotions-advisor |
| Regulatory/compliance requires SMS | Cost-sensitive high-volume → WhatsApp (lower per-msg cost in many markets) |
For production SMS: Use a Messaging Service (messagingServiceSid) instead of a raw from number. It enables sender pool management, compliance toolkit, SMS pumping protection, link shortening, and message scheduling. See twilio-messaging-services.
Every outbound SMS requires a from Twilio number (or messagingServiceSid) and a to recipient — both in E.164 format.