Key Takeaways
- Spring Boot notifications on an Android SMS gateway are transactional alerts via HTTPS JSON — not a Spring SMS SDK and not unlimited carrier send.
- Idempotency per incident/order id; backoff on 5xx; fail closed on allowance exhausted.
- Keep OTP/alert SIMs off promotional traffic.
- You bring phone and operator airtime. Service fee is devices + volume.
- No Unlimited SMS titles. Free pauses at the lifetime SMS cap.
Spring Boot SMS Gateway with Android Device — notifications is the paging lane on your SIM. Transactional SMS · API overview. Spring HTTP: Rest clients. Docs: Developer Center.
Devices and send volume. You fund the SIM.
Page humans when the phone is online — not when last-seen is hours old.
Notifications ≠ marketing blasts
Incident, shipping, and payment texts are short and consented as transactional. Do not piggyback promo copy on the same device pool as OTP.
A notification storm that retries without Idempotency-Key is how on-call gets three texts for one alert.
How to send alerts from Spring
- Map business event → Idempotency-Key.
- RestClient/WebClient POST JSON.
- Persist message id.
- Update on webhook DLR.
curl -X POST "https://app.sms-gateway.app/api/v1/messages" \
-H "Authorization: Bearer $SMS_GATEWAY_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: 3f1b0c8a-9d2e-4c77-9f5a-2b6d1e0f4a83" \
-d '{"to":["+14155552671"],"text":"Your verification code is 481920","type":"sms"}'Notification checklist
| Check | Pass |
|---|---|
| Key in env | Not in repo or APK |
| Idempotency-Key | Incident/order id |
| Body | No tokens/passwords in SMS |
| Device pool | Isolated from bulk |
| Retry | 5xx backoff; stop on delivered |
| Allowance | On Free and Developer, sending pauses when you use the plan SMS allowance rather than silently billing aggregator-style overage. Upgrade or request a custom allowance to continue. |
RestClient / WebClient is REST
No Complete Spring SMS SDK. Confirm live JSON in Developer Center. Idempotent send.
Device health before paging humans
Check last-seen and prepaid before you declare “SMS broken.” Overnight uptime · DLR.
Next steps
Fire one staging alert to staff; assert single SMS + delivered webhook. Downloads. Free: 300 SMS lifetime.
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
