A simple text-based (SMS) notification API. It will provide REST API to order a delivery and it will send messages using AT commands issued to USB 3G/4G modem. In my case it's Sierra Wireless EM7455 (based on Qualcomm Snapdragon X7), which I found in Lenovo X1 Carbon 4th Gen.
The setup will be kinda complex as it would require appropriate modem and system configuration. Complete instructions will be available in the project docs. For now, the project contains only the API part (WIP), so you run it with just dotnet run.