Call intercepted, but no trace of values

[Missing User]

Hi everyone. I'm using Fiddler Everywhere on mac to intercept calls from the smartphone app to the vaccum robot, so i can use those commands to integrate the robot into my home automation system (Home Assistant).
so I set up Fiddler Everywhere, set up the proxy in the ios wifi and installed the certificates, and correctly intercepted the commands sent.
however, there are some "parameters" that i can't intercept, let me explain with one of the cases as an example: the robot obviously drains the battery when it's working. when it finishes cleaning, it goes back to the charging base. keeping the mobile phone active during the robot charging process, I see that for every percentage point of charge acquired, a post call is sent, of which I see url, headers and payload, but there's absolutely no trace of that percentage value (or any other info related to the battery). however, obviously on the smartphone I see that variation, so somehow the information has to go through.
so the question is: what can be the case that I can't catch THAT particular detail? what tests can i perform?
I hope I've explained it well enough, if necessary I can provide screenshots (app screen and details of the intercepted traffic).

Thanks

[Rosen Vladimirov]

Hello AndKer,

That is a really interesting usage of Fiddler Everywhere and thanks for sharing the details. Using the product for a reverse engineering a specific communication is definitely one of our goals.
So, for your question - I've found a colleague of mine, who has done something similar before with their own vacuum cleaner. The information I got was that the communication happens in multiple ways - some data is shared between the application on your device and the cloud servers. But there's also UDP communication between your device and the vacuum cleaner. So I'm not sure where the percentages will be sent. What you can try is search for existing implementations of the communication. For example, for Xiaomi devices, there are various resources in GitHub. Maybe the protocol for communication is already reverse engineered somewhere. Also, keep in mind UDP communication cannot be captured with Fiddler Everywhere.
Apart from that, I've asked my colleague how to get the percentages of the battery and they mentioned a separate info request is sent to the vacuum cleaner to get this data. Maybe you need to do something similar.

Hope this helps and thanks again for sharing your scenario.

Regards,
Rosen Vladimirov
Progress Telerik