API v2 for iOS, Mac OS X, Windows, Linux, Android - need strategic advice

Hi Robert, our normal recommendation is to use the platform specific SDK for each platform, as available. So, that would be SwiftyDropbox for Swift (and the forthcoming Objective-C library for Objective-C. ETA August), the .NET SDK for Windows, the Java SDK for Android, etc.

If you need to support all of these though, that indeed could be more overhead than you'd want, as you mentioned. It sounds like an official C++ SDK would be a good solution for you, but unfortunately Dropbox doesn't offer one. I'll send this along as a feature request though.

That being the case, you can implement the HTTPS endpoints directly in your own C++ code:

https://www.dropbox.com/developers/documentation/http/documentation

That sounds like it may be a good solution for your scenario.

Using the upcoming Objective-C library for iOS and Python on desktop like you mentioned also seems like a good compromise though. Of course, that's really up to you.

Regarding the authorization flow, I'm not sure what issues you're referring to on iOS 9.2 and 9.3, but I don't expect OAuth to be a problem on iOS going forward. (We've been using it on iOS for a long time without any major issues.) Further, you don't necessarily need a "custom" URI. There are various ways to handle it, but for example if you process the app authorization in an in-app browser, you can use a more standard redirect URI, e.g., https://www.dropbox.com/1/oauth2/redirect_receiver , which Dropbox offers for this purpose.

In any case, the app authorization flow does need to go through a browser. Your app shouldn't handle the user's credentials directly.

Also, your app should never scrape/parse the HTML of the Dropbox web site itself. In addition to being a brittle implementation, since the site changes without notice, that's against the Dropbox terms ( https://www.dropbox.com/terms#acceptable_use ). All of the platforms you listed have browsers anyway though, so that shouldn't be an issue.

Hope this helps!