12-Zone Wired Smart Alarm Panel - Konnected Alarm Panel Pro (Board Only) - Make Wired Alarm System Smart - SmartThings, Alexa - No Batteries - No Monthly Subscription - Wi-Fi - Ethernet - PoE

They provide a lot of great resources and amazing tech support to get you through it. This is the winning choice over individual, battery operated devices at every window/door

Super easy to install. I hooked up 3 door sensors and 2 motion sensors from an old ADT system and powered it with PoE. Whole setup took about 30 mins minus the time to run an ethernet cable to the alarm control box.After setup, I added an ESPHome device to Home Assistant and the sensors all came right up.

This is an exceptionally useful and unique product. I have a bunch of them in service. You can replace a traditional wired alarm system for home or business, but you can also just use it for general GPIO applications, such as sensing and actuating things in the physical world programmatically. There are many ways to interface/interact with the board, but the most notable way is via existing open platforms and protocols, such as OpenHAB, HomeAssistant, MQTT. IMO you might not be happy if you're expecting to 'simply' load an app on your phone, and have it do what you want via 'the cloud' like a paid service. Maybe that's possible, but I don't know because that's not why it's unique. What makes this product remarkable is its flexibility and power when put to use by smart-home/IOT enthusiasts, experts, tinkerers and integrators.