Multi-Channel Messaging

Salami Gateway supports multiple messaging channels beyond plain SMS. This document covers how channel selection works, which providers support which channels, and how to use the channel field.

Supported Channels

How Channel Selection Works

The channel is determined by the SMS App configuration, not per-message. When you create an SMS App, you select its channel type. All messages sent through that app use that channel.

Setting the Channel

When creating an SMS App in the dashboard, select the channel:

Filtering Apps by Channel

You can query apps by channel using the scope:

// Internal usage example
SmsApp::channel('whatsapp')->get();

The API currently returns all apps; filter by the channel field in the response.

Channel-Specific Behavior

SMS (Plain Text)

• Message length: 160 characters per segment (GSM-7 encoding) or 70 characters (UCS-2 for Unicode).
• Multi-part: Long messages are split into segments. The message_parts field tracks the count.
• Sender ID: Phone number or alphanumeric sender ID (provider/country dependent).
• Delivery reports: Available from most providers.

MMS (Multimedia)

• Content types: Images (JPEG, PNG, GIF), video, audio, vCard, PDF.
• Payload: Provider-specific. Some providers accept media URLs, others require base64 content.
• Size limits: Typically 300KB-600KB depending on the carrier.
• Availability: Limited to providers with MMS support.

MMS-capable providers:

Voice

• Text-to-speech: Send a text message that is read aloud to the recipient.
• IVR: Interactive voice menus (provider-dependent).
• Call records: Stored in the calls table, accessible via GET /api/sms/apps/{app}/calls.
• Duration: Call duration tracked in seconds.

Voice-capable providers:

WhatsApp

• Business messaging: Send and receive WhatsApp messages via business APIs.
• Templates: Some providers require pre-approved message templates for outbound messaging.
• Rich media: Images, documents, locations, contacts.
• Read receipts: Available from most WhatsApp providers.

WhatsApp-capable providers:

Channel in Message Records

The channel field is stored on each message record, indicating which channel was used:

{
  "id": 156,
  "to": "254712345678",
  "from": "+15551234567",
  "message": "Hello!",
  "channel": "sms",
  "folder": "outbox",
  "status": "delivered"
}

For WhatsApp messages:

{
  "id": 157,
  "to": "254712345678",
  "from": "+15551234567",
  "message": "Hello via WhatsApp!",
  "channel": "whatsapp",
  "folder": "outbox",
  "status": "delivered"
}

Choosing a Channel

Provider Capabilities Quick Reference

See Providers for the complete matrix with all 128+ providers and their supported channels.

Related Documentation

• SMS API Overview
• SMS Apps
• Sending Messages
• Providers