Introduction
Zend is one API for messaging across channels. Send SMS, WhatsApp, voice, and email through a single endpoint, with automatic channel fallback, delivery tracking, and scheduling built in.
Instead of integrating a separate provider for each channel, you send every message to the same POST /messages endpoint and tell Zend which channels to attempt. Ready to send your first message? Jump to the Quickstart.
What Zend does
- One endpoint for every channel. Reach recipients over SMS, WhatsApp, voice, and email without wiring up separate integrations.
- Channel fallback. List channels in order of preference and Zend attempts each until one delivers.
- Delivery tracking and webhooks. Follow every message from queued to delivered, and receive real-time status updates via webhooks.
- Scheduling. Queue messages for future delivery with scheduling.
Supported channels
| Channel | Template required | Cost | Best for |
|---|---|---|---|
| SMS | No | 0.035 | Simple notifications |
| Yes | 0.065 | Rich media, buttons |
Choose channels per message with the preferred_channels field. When you list more than one, Zend attempts them in order until a delivery succeeds.
Note
body field with no template.Message types
Simple messages
Direct text messages sent through the body field. No template required — works with SMS.
Template messages
Pre-approved content referenced by template_id. Required for WhatsApp, and they support buttons and media.
Bulk messages
Send to multiple recipients in a single request, with personalized content per recipient. A cost-effective way to reach a list.
Next steps
- Quickstart — get an API key and send your first message.
- Send SMS — the SMS channel in detail.
- Send WhatsApp — templates, media, and buttons.