Thanks! I hadn't run into xAuth before. It looks like a reasonable way to make the grant process not such a Desktop UI cluster$%$^ - which I totally agree that

Thanks! I hadn't run into xAuth before. It looks like a reasonable way to make the grant process not such a Desktop UI cluster$%$^ - which I totally agree that it is. Re: the keychain thing, again, it depends on the level of compromise, whether the machine is unlocked, what platform you're on and whether the creds are in there. And yes, with enough access you can keylog, man-in-the-browser or "desktop phish", but it's higher risk for the attacker and requires maintaining longer-term access. But if your app stores passwords the user instantly loses. Failure modes matter. A kind of parody version of how I see your argument is: "Sites shouldn't bother hashing passwords, because an attacker with a shell could just modify the site's login process to capture passwords".