Twilio
RCS Business Messaging upgrades SMS with branded conversations featuring images, suggested replies, and read receipts delivered natively on the recipient’s phone. Twilio Programmable Messaging supports RCS via the same API used for SMS, allowing reuse of existing integrations. This tutorial teaches building an RCS campaign in .NET 10, requiring a Twilio account, registered RCS Sender, Messaging Service, ngrok, and a code editor. The process includes creating a rich card template with hero image, dynamic placeholders, and three buttons (Shop the sale, Send promo code, Unsubscribe), then broadcasting personalized messages via the Twilio helper library while capturing status and replies through webhooks exposed by ngrok. Test devices receive messages without waiting for full RCS sender approval, and the server terminal outputs inbound replies and status callbacks in real time.