Key Takeaways
- Make + an Android SMS gateway is a custom webhook plus an HTTP module to POST /messages — not a first-party Make app we ship.
- Outbound: scenario HTTP to app.sms-gateway.app with Bearer from Make’s secret store. Inbound: our HMAC webhook into a Make custom webhook.
- Confirm live JSON in Developer Center. Map 200 to accepted, not delivered.
- Idempotency-Key per Make execution. Isolate OTP devices. Pace to last-seen.
- You bring the phone and operator credit. Platform pricing is devices plus send volume.
Make is HTTP, not a plugin
Hub: Android SMS gateway API. Product webhooks: SMS webhooks. Make’s own webhook help: make.com webhooks. Live fields: Developer Center.
We meter devices and volume. A prettier scenario does not include pulsa.
Two directions
Outbound: Make HTTP module POST https://app.sms-gateway.app/api/v1/messages with Authorization: Bearer from a scenario variable — not a note on the canvas. Inbound: subscribe to message.delivered / message.failed / message.received and point the URL at Make’s custom webhook.
“If the only ‘integration’ is a Google Sheet that Make polls, you built a delay machine. Webhooks exist so the radio can talk back.”
Scenario failure modes
| Symptom | Likely cause | First check |
|---|---|---|
| Duplicate SMS | Make auto-retry, no Idempotency-Key | Stable key = bundle + recipient |
| 200, CRM says delivered | HTTP mapped to DLR | DLR |
| No inbound module fire | URL, TLS, HMAC headers ignored | X-SmsGateway-Signature |
| OTP late during a sale | Same device as the blast | Named OTP pool |
| Pending pile | Scenario faster than last-seen | Pairing |
HMAC or do not trust it
Verify timestamp + body before the scenario writes CRM. RFC 2104. cURL tests: webhook receive.
Keep OTP off the blast scenario
Isolate OTP. STOP: auto-reply. Pricing.
Next steps
Canary one staff number from a tiny scenario. Confirm HMAC on inbound. Operator credit stays yours.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- SMS webhook integrationInbound and status events
- SMS API documentationLive endpoint reference
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
