SKILL.md
Overview
A single messages.create() call sends on any messaging channel — SMS, MMS, RCS, or WhatsApp. The channel is determined by the sender address and the recipient's capabilities. For channel selection guidance and the full onboarding sequence, see twilio-messaging-overview and twilio-messaging-channel-advisor.
| Channel | to format |
Notes | Template required? |
|---|---|---|---|
| SMS/MMS | +15551234567 |
MMS: US/CA/AU only | No |
| RCS (with SMS fallback) | +15551234567 |
Send via Messaging Service that has both an RCS sender and an SMS sender — Twilio attempts RCS first, falls back to SMS on failure | No |
| RCS (no fallback) | rcs:+15551234567 |
Forces RCS only — fails if recipient isn't RCS-capable | No |
whatsapp:+15551234567 |
Send via whatsapp:-prefixed from |
Outside 24-hr window: yes |
For production: Send via messagingServiceSid instead of from. This enables sender pool management, RCS→SMS fallback, SMS pumping protection, link shortening, compliance toolkit, and scheduling. See twilio-messaging-services.