Key Takeaways
- android sms gateway open source dual sim is a slot-map problem on a DIY phone stack — not a second free modem.
- Do not rewrite the open-source hub here. This spoke is dual SIM only.
- SMS Gateway is a maintained control plane plus Android app. Compare it honestly; do not pretend we are that GitHub repo.
- Two SIMs in one chassis still share battery, OEM sleep, and one device slot on a hosted plan.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. OSS licenses do not include operator airtime.
- Free 300 SMS lifetime is a canary on the maintained path, not a DIY SMS pack.
Searchers for android sms gateway open source dual sim usually have a dual-tray phone and a GitHub README. The category hub is open-source Android SMS gateway. This spoke is narrower: what two SIMs buy you, and what they do not.
Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
Two SIMs in a phone that Dozes is still one offline box. Dual tray is operator diversity, not a spare gateway.
Hub owns the OSS category
Score repos on commits, DLR/webhooks, and OEM battery docs — not stars. We do not maintain those forks. If you want a hosted plane, pair from setup and keep live fields in Developer Center.
We are not an open-source dual-SIM fork
SMS Gateway ships a downloadable Android app and a commercial API. Dual SIM on this path is documented as device/slot targeting, not a self-hosted AT daemon. Do not paste our Bearer JSON into a local OSS listener and call it the same contract.
Two slots vs two devices
| Setup | What you gain | What still fails together |
|---|---|---|
| One phone, two SIMs | Operator diversity, cheaper KYC | Battery, Doze, USB, the chassis |
| Two phones, one SIM each | True failover chassis | Nothing shared except your runbook |
| OSS local HTTP on the phone | Air-gap possible | You own patches, TLS, 02:00 pages |
| Hosted control plane | Keys, queue, DLR in one account | Still your SIMs and airtime |
Slot maps drift
After reboot or SIM swap, “slot 1 is OTP” becomes a lie. DIY stacks that address SIMs by index without a re-pair step will send login codes out the promo MSISDN. Re-canary both destinations. Feature surface on the hosted path: multi-device dual SIM.
Do not put promo on the OTP slot
Two SIMs are useless if both lanes share one blast. Isolate OTP. STOP still applies on promotional copy. Priority queues cannot save a single radio that is already sending a campaign.
What DIY dual-SIM actually costs
You still buy airtime twice. You still fight OEM killers once. Hosted device caps count phones, not trays — see devices + volume. Starter, Professional, and Business list Unlimited SMS as platform send volume; that is not unmetered carrier SMS. Fair-use remains.
Checklist
- Hub article read; repo identified by URL, not nickname.
- Slot → purpose written; re-tested after reboot.
- OTP MSISDN ≠ promo MSISDN.
- OEM battery exemptions on that chassis.
- Airtime wallets named per SIM.
- Honest comparison: DIY ops vs hosted plane.
Next steps
Stay on the OSS hub for shopping. For production OTP on a maintained path, pair a phone and keep two SIMs as diversity — not as a spare server.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- multi-device and dual SIM routingCapacity and failover
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
- SMS API documentationLive endpoint reference
