Wallet interaction

I’m trying to understand how wallet interaction works under the hood with the purpose to try to implement these principles in a Go served app. I found protocol descriptions under AEX-2 and AEX-5, which are very helpful for the structure of the used JSON-RPC messages. The Go SDK doesn’t support wallet interactions at the moment, so that’s no option either at the moment.

What I don’t understand is where I should send these JSON-RPC request, probably because I don’t understand how wallets exactly work. Some are browser extensions, which are in fact progressive apps if I am not mistaking. The base aepp is either a mobile application or a progressive app installed on the home screen. Are they simply accepting requests on some port?