Key Takeaways
- flask sms gateway with android device notifications is an RQ/Celery job POSTing HTTPS JSON — not a “Complete Flask SDK”.
- Do not call the gateway inside the Flask request. gunicorn timeouts are not DLR.
- Flask is slimmer than Django: you still need a broker, a worker, and a signed callback.
- Pin OTP on another deviceId from shipping/notify templates.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Retries that transmit still spend carrier credit.
- Docs own live fields.
RQ worker, not a Flask SDK
Search intent for flask sms gateway with android device notifications is a small Python app that still respects radio physics. Service pricing is based on device count and total SMS sent through the gateway. Flask is not a lighter SDK — it is a lighter web layer. Contract: docs.sms-gateway.app. Flask’s own docs stop at HTTP (flask.palletsprojects.com); SMS still leaves your Android SIM.
A 50-line Flask app can still double-send OTP if RQ retries without Idempotency-Key. Slim is not the same as safe.
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"}'That curl is the contract your worker should speak. Django’s fuller ORM stack: Django notifications.
Blueprints vs the radio
Keep /notify idempotent at the application layer: enqueue once, return a job token. Do not hide a synchronous send behind “it’s just Flask.”
| Layer | Flask shape | Trap |
|---|---|---|
| App | Blueprint returns fast; job id stored | requests.post in the route |
| Worker | RQ worker with timeout & backoff | threaded send that dies with the dyno |
| Idempotency | Header = notify event id | job.retry() minting a new key each time |
| Callback | Separate blueprint; HMAC; no Flask session cookie | Unsigned /hooks that marks Delivered |
Redis/RQ and Idempotency-Key
Worker crashes replay jobs. The gateway header must be the notify event id, not uuid4() inside the task. Back off on 429.
Webhook blueprint
Separate from session auth. SMS webhook integration. Webhooks setup. Verify HMAC on the raw body.
Keep login codes off notify
Two queues, two deviceIds. OTP verification. Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
Flask checklist
- RQ/Celery worker running beside gunicorn.
- Idempotency-Key = business event.
- Webhook blueprint signed + idempotent.
- Notify SIM ≠ OTP SIM.
- Staff canary before customers.
Next steps
Enqueue one staff SMS, confirm DLR, then open the route. Pricing. Setup.
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
