Key Takeaways
- A device-health checklist for the Android SMS gateway API is last-seen, battery, OEM, prepaid, and Pending age — not a 200 from POST /messages.
- The API accepts; the SIM delivers. On-call that only graphs HTTP latency will miss a sleeping Pixel.
- This is not production-readiness (keys/webhooks) and not compliance (consent). It is the dock.
- Service pricing is based on device count and total SMS sent through the gateway. You need a working Android phone with a SIM and SMS credit from your mobile operator. Operator message costs are yours—we do not sell carrier SMS balance.
API teams treat device health as someone else’s problem. It is not. Every Bearer POST still leaves a specific Android. If that dock is OEM-asleep, unpaid, or at 4% battery, your JSON success is a lie you tell the product manager.
Service pricing is based on device count and total SMS sent through the gateway. Setup: device setup. DLR: delivery reports. Keys: production-readiness.
A dashboard that is all 2xx and a phone that is all dark is how OTP pages time out with “the API is fine.”
HTTP green is not a healthy radio
Watch last-seen and Pending age next to request rate. Webhooks for delivered/failed. Confirm fields in OpenAPI.
Health gates
| Gate | Pass | Fail |
|---|---|---|
| Last-seen | Minutes, not hours | Silent since yesterday |
| Power | Charging or docked, OEM exempt | Battery saver, 4% |
| SIM | Signal + prepaid/postpaid funded | Airplane, empty balance |
| Pending | Queue age within SLO | Growing while HTTP still 2xx |
| Spare | Paired, counted in device slots | In a drawer |
What on-call actually watches
You need a working Android phone with a SIM and SMS credit from your mobile operator. Operator message costs are yours—we do not sell carrier SMS balance. Spare strategy: backup device. Failover: multi-device failover.
API senders still own the dock
Name the human who gets paged when last-seen dies — not “infra in general.” App.
OTP dies first
Isolate OTP deviceIds. OTP. Promo bursts must not empty the login radio.
Checklist
- Last-seen alert with an owner.
- OEM battery exemptions documented per model.
- Prepaid check in the runbook (or postpaid cap).
- Pending age SLO.
- Spare paired and funded.
- DLR fail rate next to HTTP success rate.
Next steps
Unplug the canary phone. Confirm the page fires before a customer notices. Device slots if the spare needs a plan bump.
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
