Messaging Channels: SMS, RCS, and WhatsApp
The Qlara Platform API supports three messaging channels. Each channel serves different use cases and has its own capabilities, reach, and requirements.
SMS
Short Message Service is the most widely supported channel. Every mobile phone can receive SMS, making it the best choice when you need universal reach.
- Content: Plain text only (up to 160 characters per segment, concatenated for longer messages).
- Templates: Not required. You can send any text content.
- Delivery receipts: Available via polling or webhooks.
- Best for: Transactional notifications, OTPs, alerts, reminders.
API endpoint: POST /message-server/sms/send (SMS Universal API)
RCS
Rich Communication Services brings rich media capabilities to the native Android messaging app. RCS messages support images, carousels, buttons, and suggested actions.
- Content: Text, images, cards, carousels, and interactive buttons.
- Templates: Required. Create and manage templates via the API before sending.
- Delivery receipts: Available via polling or webhooks.
- Best for: Marketing promotions, product showcases, interactive customer engagement on Android.
API endpoints: Dedicated RCS Send and RCS Templates APIs.
WhatsApp
WhatsApp Business API lets you reach users on the world's most popular messaging app. WhatsApp enforces strict template approval policies through Meta.
- Content: Text, images, documents, videos, buttons, and list messages.
- Templates: Required and must be approved by Meta before use. Templates are associated with a phone number.
- Delivery receipts: Available via polling or webhooks.
- Best for: Customer support, order updates, appointment reminders, marketing (with opt-in).
API endpoints: Dedicated WhatsApp API for sending messages and managing templates.
Comparison
| Feature | SMS | RCS | |
|---|---|---|---|
| Rich media | No | Yes | Yes |
| Template required | No | Yes | Yes (Meta-approved) |
| Delivery receipts | Yes | Yes | Yes |
| Two-way messaging | Limited | Yes | Yes |
| Reach | Universal | Android | WhatsApp users |
| Approval process | None | Internal | Meta review |
Choosing a channel
- Need universal reach? Use SMS. It works on every phone.
- Targeting Android users with rich content? Use RCS for native rich messaging.
- Reaching WhatsApp users? Use WhatsApp for high engagement rates and rich media.
- Not sure? Start with SMS for reliability, then add RCS or WhatsApp for richer experiences.
Tracking delivery across channels
Regardless of the channel, you can track delivery using:
- Polling:
GET /messages/status/{messageId}returns the current delivery status. - Webhooks: Configure an HTTPS callback to receive real-time status updates. See the Webhooks guide.