Does this sign commands?

[bogdanripa]

Are API requests (the commands) that are being sent signed?

On their documentation I see that:

The Vehicle Commands Proxy exposes endpoints identical to the ones described below. When it receives a request, it signs the command with a Fleet Key key before passing the request to Fleet API. If a command is not signed, the vehicle will reject the request and perform no action. This ensures unauthorized parties are not able to send commands.

[Bre77]

No I have not built that capability yet. I have attempted to but was unsuccessful.