ok so there is wired vs battery
and then there is communication protocol
most contact sensors send to be battery powered and therefore also tend to avoid wifi for power efficiency (although they definitely do exist in wifi versions)
a lot tend to be either BLE or zigbee
some brief and limited info on these protocols
for BLE (bluetooth low energy) you need to add bluetooth to your HA server either directly or via a proxy. either would need to be in range.
for zigbee you need a "zigbee coordinator" which is likely what devices mean when they say "needs hub". if a device is zigbee you dont need a specific hub you just need to have a zigbee network. you can add a coordinator directly to your server by usb or you can get a network based one.
hopefully this general information can help you find a starting point in your research.
if you post what kind of setup and other devices you have I or others can maybe recomend something suited.