Sparrow is the routing layer in front of WhatsApp, RCS, SMS, email and Telegram. Define a SmartQueue graph — try one channel, fall back to the next. One API. One credit per send. Bring your own keys for a discount.

SMS / WhatsApp / RCS
SMS
Bot API
Plug in once. Six providers, one billing model, one analytics surface.

All the providers, none of the integration cost.
Routing
POST to /messages. Sparrow runs your SmartQueue graph — WhatsApp → RCS → SMS, or any path you design. Fallback on outage, retry on 429.
Billing
Same credit cost per send regardless of provider. Predictable invoices, no per-route accounting.
BYOP
Use your Mailgun, Twilio, or SMTP keys directly. Pay only the platform management fee.
Rate limits
Set per-minute and per-day caps on each API key. Burst protection on by default.
Webhooks
Receive delivered / bounced / opened / clicked at your URL. HMAC-SHA256 signed.
Analytics
Deliverability and error rate normalized across providers. Side-by-side comparison.
No SMTP wrangling. No provider-specific code paths.

sparrow tenant providers add mailgun --label production
sk_live_3mF8z...
curl -X POST .../messages -H "Authorization: Bearer $KEY"

curl https://api.sparrow.dev/api/0.1/public/messages \
-H "Authorization: Bearer $SPARROW_KEY" \
-H "Content-Type: application/json" \
-d '{
"channel": "SMS",
"to": "+33600000000",
"text": "Your code: 7421"
}'{
"messageId": "a8d2-...-c91",
"status": "QUEUED",
"chargedCredits": 4,
"provider": "TWILIO"
}
# webhook 2.4s later:
{
"messageId": "a8d2-...-c91",
"event": "delivered",
"provider": "TWILIO"
}Same credit cost across providers. BYOP unlocks lower per-send fees.
Ready when you are
Free tier, no credit card. Pay only when you scale.