Android Java SMS Sender

I need an Android-only solution that quietly installs on a phone and listens over the local network (Wi-Fi) for two simple parameters coming from my desktop or server: the destination number and the SMS text. Once received, the service should fire off the message through the device’s native SMS manager—no on-screen interface or notifications, just a background service that starts with the device and keeps running.

Because it will run headless, please take care of permissions (SEND_SMS, RECEIVE_BOOT_COMPLETED, FOREGROUND_SERVICE where required) and any battery-optimization whitelisting so messages are never blocked. I’m fine with classic Android Java; no Kotlin is needed unless you feel it speeds development. Communication can be your choice of lightweight REST endpoint, WebSocket, or simple TCP socket as long as it’s over Wi-Fi and I can invoke it with a short script from my computer.

Deliverables:
• APK and signed release build
• Complete Java source with concise README explaining how to call the service (sample curl command or Python snippet)
• Brief instructions for granting the required permissions on Android 10+
• Clear description about codes for further development or upgrades in the future.

I’ll test by sending a batch of numbers and texts from my PC; success means all SMS reach the target devices without any UI popping up.