Source
Public repository
GitHub
Android repository accessPublic GitHub prototypeAndroidKotlin
SmsService: build a local SMS gateway from an Android phone.
This page is for getting, building, installing and testing the prototype. The separate tool page explains architecture, trade-offs, limits and comparison with managed SMS providers.
Build
Debug APK
./gradlew assembleDebug
Install
Android phone
./gradlew installDebug
Endpoint
Local gateway
POST /send_sms
Operational diagram
The phone becomes the local bridge between backend and SIM card.
The flow must stay private: frontend triggers an action, backend controls the request, then SmsService relays the SMS through the Android phone.
01 · UI
Frontend / Admin
User action, OTP request or controlled workflow.
02 · API
Backend API
Consent, purpose, rate limits, templates and logs.
03 · Wi-Fi
Private network
Private Wi-Fi or controlled LAN. No public internet exposure.
01
Frontend / Admin
User action, OTP request or controlled workflow.
UI
02
Backend API
Consent, purpose, rate limits, templates and logs.
API
03
Private network
Private Wi-Fi or controlled LAN. No public internet exposure.
Wi-Fi
04
SmsService Android
Foreground service on a controlled Android phone.
Android
05
SIM card
Operator plan delivery with fair-use boundaries.
SIM
06
Recipient
Consent-based transactional message delivery.
SMS
Frontend / Admin → Backend API → Private LAN → SmsService Android → SIM plan → Recipient
Quick start
Build, install, verify.
The download page stays practical: open the repository, generate the debug APK, install it and test the local endpoint.
Gradle commands
Android · Clean Gradle build
./gradlew cleanAndroid · Build debug APK
./gradlew assembleDebugAndroid · Install debug APK
./gradlew installDebugOutputs and endpoint to verify
app/build/outputs/apk/debug/app-debug.apkPOST http://PHONE_LOCAL_IP:5000/send_smsWhy it is interesting
The value is the local model, not an absolute free promise.
Managed SMS provider
- Managed delivery infrastructure.
- Usage-based billing that grows with volume.
- Carrier handling, compliance and deliverability handled by the provider.
SmsService local model
- No per-SMS provider bill when the SIM plan includes SMS.
- Phone, SIM, electricity, maintenance, monitoring and fair-use still exist.
- Relevant for controlled small volumes, prototypes and internal tools.
Limits
Do not present it as a public SMS platform.
Not a spam tool.Not a public internet gateway.Not a universal replacement for Twilio or managed SMS providers.Secrets visible in public repositories must be rotated before real use.Compliance, consent and carrier limits remain mandatory.
What you need
Not a magic API: a small local system that must be operated properly.
Android phone
Android phone
A stable, charged and controlled device allowed to send SMS.
SIM card
Active SIM
A suitable plan, ideally with included SMS and known carrier limits.
Private LAN
Private network
The backend must reach the phone on LAN, not through the public internet.
Backend
Disciplined backend
Validation, consent, anti-abuse, logs, monitoring and fallback.
Verified offers
A space ready for legal offers, partners and promotion codes.
Offers will stay separate from the technical catalog: official source, validity date, sponsored mention when needed, and verification before publication.
01
Official sources
No suspicious keys, no grey links, no unverifiable promise.
02
Promo codes
Each code can have a date, source, platform and verification status.
03
Monitoring
The backend can check URLs every night and trigger an alert if something changes.
Back to downloads
SmsService
A public Android/Kotlin prototype for turning a controlled Android phone into a private local SMS gateway.