> ## Documentation Index
> Fetch the complete documentation index at: https://docs.belio.co.ke/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

Belio Messaging lets you send outbound notifications and customer messages over two channels:

* **SMS** for broad reach and simple, fast delivery to Safaricom and Airtel mobile numbers. Supports both plain messages and pre-approved templates.
* **WhatsApp** for richer, template-based messaging through a WhatsApp Business Account (WABA), including structured content and better branding.

Both channels are designed for programmatic sending at scale, with optional delivery tracking via callbacks (delivery receipts).

## Choose a messaging channel

Use **SMS** when you need maximum reach (OTP, alerts, short updates) and want the simplest integration: pick an SMS service, provide recipients, and send. SMS also supports templates for pre-approved, reusable message formats.

Use **WhatsApp** when you need template-driven messaging (transactional updates, customer engagement, and branded communication) and you already have:

* A configured **WABA** (*WhatsApp Business Account*) and verified phone number.
* **[Approved message templates](./whatsapp/templates/introduction)** to send.

## Common Concepts

Across SMS and WhatsApp, you will typically work with:

* **[Authentication](/authentication)**: All requests use Bearer token authentication.
* **[Authorization scopes](https://cloud.belio.co.ke/team-overview/api-access-keys)**: Your API Client must include the appropriate scope for the channel you are using:
* SMS → `message.sms.send.oneway`
* WhatsApp → `message.whatsapp.send`
* **Recipients**: Use phone numbers in international format (E.164), e.g. `+254712345678`.
* **Delivery receipts (callbacks)**: Optionally include `receiptRequest` with a `correlator` and `callbackUrl` to receive asynchronous status updates.

## Next Steps

Choose a messaging channel to get started:

#### SMS

* [Introduction](./sms/introduction)
* [Templates](./sms/templates/introduction)
* [Send Message](./sms/send)
* [Template Parameters](./sms/templates/parameters)

#### WhatsApp

* [Introduction](./whatsapp/introduction)
* [Templates](./whatsapp/templates/introduction)
* [Send Message](./whatsapp/send)