Smart Channel Routing
channel: "auto" in POST /v1/verify/send activates smart routing. SendAPI automatically selects the best channel for each destination — prioritizing the cheapest option with the highest delivery rate.
Routing Logic
1. WhatsApp available for this number? → Send via WhatsApp
2. WhatsApp not available → Send via SMS
3. SMS unavailable for this region → Send via Email (if to= is email)Why WhatsApp First?
WhatsApp OTPs cost significantly less than SMS in most markets and have higher open rates (typically >98% vs ~70% for SMS). For countries like Rwanda, Kenya, Nigeria, and India — where WhatsApp penetration exceeds 70% — this results in 40–60% cost savings.
Channel Cost Comparison
| Channel | Avg. Cost (per OTP) | Delivery Rate |
|---|---|---|
| ~$0.002 | >98% | |
| SMS | ~$0.010–$0.075 | ~70–90% |
| ~$0.0001 | >99% |
Per-Country Channel Configuration
Smart routing uses per-country WhatsApp penetration data to decide. Countries with >60% WhatsApp penetration default to WhatsApp. This configuration is updated monthly.
| Country | Default Channel |
|---|---|
| Rwanda | |
| Nigeria | |
| India | |
| Brazil | |
| United States | SMS |
| Germany | |
| United Kingdom | SMS |
Forcing a Channel
You can always override smart routing by explicitly setting the channel parameter:
json
{
"to": "+447700900000",
"channel": "sms"
}Valid values: sms, whatsapp, email, auto