What alarm system do you currently have? (This is to ensure AlarmDecoder would be compatible.)
If you get the AlarmDecoder AD2PI network appliance it would I believe include the Raspberry Pi you need however it seems to be out of stock. Otherwise you need to add a Raspberry Pi to your shopping list. I would advise you contact them directly to ensure you get what you need. If you do manage to get one of these from them it could then come pre-loaded with their software and save you doing a lot of the work.
If you want a simpler solution then a different approach is possible but only if you are only using wired sensors. (AlarmDecoder supports wireless sensors as well.)
Thanks for the reply. My alarm system is an Ademco Vista 10SE. The Alarm decoder product i have is the AD2serial and I am currently using it with my vera system. It integrates simply with vera using a plugin.
I purchased a new smarthings hub3 since it looks like vera hasn’t really improved their UI much over the last few years. The alarm setup is the only thing holding me back from converting over