Key Takeaways
- kotlin android sms gateway api send SMS: OkHttp/HttpURLConnection against HTTPS JSON — not a Gradle SDK product.
- Live path is POST /api/v1/messages with Bearer, to[], text. Confirm fields in Developer Center.
- Accept is not delivered. The Android still radios on operator credit.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
- Free 300 SMS lifetime is a staff canary.
- Same contract as /blog/java-android-sms-gateway-api-in-depth-guide.
Kotlin send-SMS samples against an android sms gateway api should look like any other HTTPS client. Sibling: Java REST. Developer Center. curl OTP.
Priced by devices and SMS send volume. You use your own phone and operator SMS credit.
If the Bearer lives in
local.propertiesthat ships with the APK, you did not integrate a gateway. You published a prepaid SIM to the Play Store.
HttpClient, not a Kotlin SDK
No Maven/Gradle product. PHP/C# pages are REST samples too — not composer/NuGet SDKs. PHP HTTPS.
Request pieces
| Piece | Role | Miss |
|---|---|---|
Authorization: Bearer | Auth from env | Query ?key= |
to[] | E.164 array | National format leftovers |
text | Body | Invented body / message |
Idempotency-Key | Retries | Duplicate OTP |
POST JSON shape
val req = HttpRequest.newBuilder()
.uri(URI.create("https://app.sms-gateway.app/api/v1/messages"))
.header("Authorization", "Bearer $apiKey")
.header("Content-Type", "application/json")
.header("Idempotency-Key", jobId)
.timeout(Duration.ofSeconds(10))
.POST(HttpRequest.BodyPublishers.ofString(json))
.build()Conceptual. Host and fields: docs.
2xx is not delivered
Webhooks · GET /messages/{id}.
OTP vs notifications
Isolate devices. OTP.
Java sibling vs this spoke
Same REST physics. This page is the send canary in Kotlin syntax.
Checklist
- Key in env, not the APK.
- Timeouts + Idempotency-Key.
- E.164 in to[].
- Staff canary.
- No SDK README.
- Docs same day.
Next steps
Pair via setup, then devices + volume.
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
