Key Takeaways
- Make.com troubleshooting for an Android SMS gateway is HTTP + HMAC + last-seen — not a missing first-party Make app from us.
- A green scenario run means the module got 2xx. Delivery is still the SIM.
- Unsigned inbound webhooks are a public send button.
- Isolate OTP scenarios from campaign scenarios and from device pools.
- Developer Center owns live fields. PHP REST samples are not a Complete SDK.
- BYO phone and operator credit. Platform meters devices and volume (Free 300 lifetime; paid from $19/mo).
Summary
Troubleshooting Make.com against an Android SMS gateway means splitting scenario success from radio success. Hub spoke — start from Make overview. REST: Android SMS Gateway API. Webhooks: webhook integration. Live fields: Developer Center.
A scenario that retries a 422 is not resilient. It is an airtime furnace with a pretty timeline.
Scenario green vs radio dead
Make HTTP modules call REST HTTPS/JSON. The Android still sends on your SIM. Make HTTP help is transport. Pairing lives in setup.
Context
Typical break: OEM killed the app overnight, prepaid hit zero, unsigned Custom Webhook fired twice, or OTP and promo share one device. We do not sell a first-party Make connector.
Triage order
- Confirm the HTTP status and response body, not only the Make “success” badge.
- Check device last-seen and battery exemptions.
- Verify operator airtime on the sending slot.
- If inbound: verify HMAC before any send module runs.
- Canary to a staff number with a dedicated scenario, then DLR.
Symptom table
| Symptom | Look here first | Do not |
|---|---|---|
| Make 200, no bubble | Last-seen, SIM balance, DLR | Add more retries |
| 401 / 403 | Env key, least-privilege scope | Paste the key into a scenario note |
| Duplicate OTP | Idempotency + webhook acks | Blind incomplete-run replay |
| HMAC fail | Raw body + clock skew | Disable verification “just for now” |
Retries still spend airtime
Every accepted send meters platform volume and operator SMS. Devices and volume. Cap incomplete-run retries.
Operations
Name an owner for the Make org, the API key, and the shelf phone. After OEM updates, re-run the canary scenario — not a customer list.
HMAC and least privilege
Inbound Custom Webhooks that trigger SMS must verify signatures. Staging keys never live in production scenarios. OTP bodies do not belong in Make execution history exports.
When to stop looping
Stop if the phone is offline or the SIM is empty. Fix radio first. If the agent/no-code path can blast without approval, unplug the key.
Checklist
- HTTP module points at Developer Center paths.
- HMAC on inbound; least-privilege key per env.
- OTP scenario isolated.
- Last-seen alert wired.
- Canary staff number documented.
Next steps
Pair in setup, keep REST canonical, and treat Make as an HTTP client — not a new SMSC.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- SMS API documentationLive endpoint reference
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
- download the Android gateway appGet the APK
