AWS End User Messaging — SMS, Voice, RCS & Notify Overview AWS End User Messaging SMS and Voice (the API) is the control and data plane for SMS, Voice, RCS Business Messaging, and Notify (OTP). This skill covers the two fastest onboarding paths — each reaches a real message on a real phone in about five minutes, with no phone-number purchase and no carrier registration: 1. Create an RCS test agent and send your first branded message — a branded RCS Business Messaging agent, a verified test device, and a rich outbound + inbound message. See references/hello-rcs-test-agent.md. 2. Send an OTP wi…