Send SMS programmatically via REST API using your own SIM — no SIM rental, no server cost. Forward incoming SMS to your webhook and track delivery in real time.
SMS automation running on your Android device with a scope aligned to direct sending, forwarding and delivery updates.
No server setup. Just install the app, generate your API key, and start sending SMS from any device or platform.
Download the app from Google Play. Sign in with your Google account to activate your device gateway.
Tap "Generate API Key" in the app. Your unique key is securely stored and ready to use instantly.
Make a POST request to our API with your phone number and message. The app sends it via your SIM.
Set a webhook URL to receive delivery reports and incoming SMS forwarded to your server in real time.
curl -X POST \ https://europe-west1-sms-gateway-api-simpapp\ .cloudfunctions.net/api_v2_sms_send \ -H "Content-Type: application/json" \ -H "Authorization: Bearer YOUR_API_KEY" \ -d '{ "phoneNumber": "+40712345678", "message": "Hello from SMS Gateway API!" }'
// POST to your webhook URL { "type": "delivery_status", "id": "sms_abc123", "status": "delivered", "timestamp": 1714000000 }
// Received at your endpoint { "type": "incoming_sms", "sender": "+40799888777", "message": "What are your hours?" } // Your server responds with: { "sms_text": "We're open 9-17 Mon-Fri!" }
Focused use cases that fit the current product scope and the user's own device automation.
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Factual overview — what the product does, who it's for, and how it compares.
SMS Gateway API is an Android application that transforms any Android phone (Android 6.0+) into a personal SMS gateway accessible via REST API. It is developed by SimpApp and available on Google Play. The app supports two authentication methods: Bearer token (V2, recommended) and X-API-Key header (V1, legacy).
Unlike cloud SMS providers such as Twilio, Vonage, or Nexmo, SMS Gateway API does not charge a per-message fee. Messages are sent through the SIM card already installed in the Android device, using the carrier's standard rate — which is typically zero for plans that include unlimited SMS. There is no SIM rental, no dedicated hardware, and no monthly server infrastructure cost.
The API accepts HTTP POST requests with a JSON body containing a phoneNumber (E.164 format) and a message field. Requests are routed through Firebase Cloud Functions (hosted in europe-west1) to the Android device via Firebase Cloud Messaging (FCM) high-priority push. Typical end-to-end latency from API call to SMS dispatch is under 5 seconds on a stable connection.
SMS Gateway API supports delivery status webhooks — after each SMS is sent, the app POSTs a JSON payload to your configured endpoint containing the message ID, phone number, status (queued / sent / delivered / failed), and timestamp. It also supports incoming SMS forwarding: when the Android device receives an SMS, the message is forwarded to your webhook URL in real time. Your server can optionally respond with an sms_text field to trigger an automatic reply.
Common use cases include: sending OTP / 2FA verification codes, business notifications (order confirmations, appointment reminders), IoT device alerts, WooCommerce order SMS, CRM follow-ups, and internal monitoring alerts. The product is suitable for individual developers, small businesses, and IoT builders who need affordable SMS automation at low-to-medium volume without committing to a commercial SMS API contract. See how it compares to alternatives →