I know what the Border Router “App” does. It runs an OTBR in a Docker container, and the OTBR uses an RCP connected via USB. That part I understand.
But after this is set up, I find there is an Open Thread integration after adding it. You enter the OTBR’s web interface URL, and then it “does something”. I assume if it needs the Border Routers REST API URL, then it does something using that Interface. But what? I can’t seem to find examples of any added functionality. I can add Thread devices without this, and there appears to be no human interface. My Border Routes run just fine without this integration. The only documentation I find tells me how to install it.
It claims that it makes adding Thread devices easier, but I don’t notice any difference.
What data is communicated in and out of this integration?
I’m not entirely positive about some of this, but in general the OTBR Integration is the one that sets up the websocket for HA Core to use when using the websocket API with the OTBR App. It likely handles the auto-discovery of the OTBR App and auto-sets the URL and the websocket.
While the Thread Integration is used mainly to manage Thread networking credentials, such as getting them from the OTBR or sending them to the OTBR, I think it does this in concert with the OTBR Integration. Similarly, while one uses the Thread Integration to change the channel, I believe it is the OTBR Integration that handles this and checks with ZHA to make sure its not using that channel. So between the Thread Integration and the OTBR Integration, a channel change request is sent to the OTBR App.