Hi there,
I have flyctl v0.0.401 installed on a Mac and have noticed that since then the device has been calling api.fly.io in the background, even when I am not actively using flyctl.
I’m wondering why that could be and if there’s a way to disable this phone-home feature?
What you’re most likely seeing is the flyctl agent, which runs in the background and holds your WireGuard sessions open. flyctl agent is the reason you can run flyctl in multiple windows, each using your WireGuard session, without the last command breaking the WireGuard session from the first. The agent pings our API every once in awhile to make sure that your WireGuard peer configuration is still valid.
You can just stop the agent, if you like; it’ll start up again automatically if you do something that needs WireGuard.
We’re not really religious about not phoning home; we’ll do whatever we can to make sure things work as smoothly as we can, and if things can be made smoother by sending the occasional ping, that’s probably what we’ll do.
We don’t do any weird analytics “you’re not the customer you’re the product” stuff. You’re definitely the customer, here. 
Thanks for the clarification, confirmed that it was flyctl agent making the call. 100% understand the use case here, makes sense!
Appreciate the quick reply here. Have a great day.
No problem at all! Not wanting your dev tools to be chatty is also 100% a reasonable thing; I figure I should just my best to set real expectations about how we think about this stuff.