Documentation

Overview

GSM Modem turns your smartphone into a GSM modem that exposes an HTTP API. Your applications can send and receive SMS by calling the API on the device where the app is installed. This is useful for automation, monitoring, two-factor authentication, and any software that needs to use a phone's modem.

Getting started

• Install the GSM Modem app on your Android device.
• Ensure your app and the device are on the same network (or use port forwarding / tunnel for remote access).
• Call the API base URL (e.g. http://<device-ip>:port) from your backend or script.
• Use the endpoints below to send SMS, list messages, and manage the modem.

API endpoints (summary)

Typical operations supported by the GSM Modem API include:

• Send SMS — POST /api/send-sms with JSON body (phone, message) and HTTP Basic auth.
• Receive SMS (callback) — Configure a callback URL in app Settings. When an SMS arrives, the app sends POST to your URL with JSON body (phoneNumber, message). You can optionally set callback username/password in Settings for HTTP Basic auth.
• Status / home — GET / returns the in-app web interface.

Exact paths and formats may vary by app version. See the in-app User Guide or the Coding examples for sample requests in multiple languages.