This is a multipart topic but I recently acquired a Rest Performance Bed (https://restperformance.com/) and am wondering if integration exists (doubtful) how easy it would be to integrate and where can I get started to learn how to make custom components for HA. The device does have a webserver built in that is all unencrypted data, so its pretty easy to see the communication for this bed. The feature that this bed has all via http are set mode, set firmness, and set sensitivity. It also reports pressure detection so you can see if there is someone laying on the bed (which could be very useful automation wise). I tried searching topics for this integration and could not find any so Id thought Id start a thread on this.
You can learn the process of building custom components from here.
If you have the api urls, then an easy way without integration would be to the http node in nodered and publishing the return data into various sensors from nodered.