I don't know enough about XenForo's internals to know what's possible out out this but at the minimum I'd need to be able to have the following in the API.
XenForo Core Features
- Login/Logout Functions
- Support 2FA
- Support Facebook, Google Auth
- I do not want them to be able to sign up using
- Ability to poll the server for update to personal things
- Moderation notices (for moderators/Admins)
- Private Messaging Support (reply and send)
- Ability to post treads and polls
- XF 1.5 Tagging Support
- XF Resource Manage/XF Media Gallery
- Full support of existing permissions
- Ability to report ports
- Ability to restrict users from using API via permissions
- Moderation handling
Important points about the actual app.
- Don't plan on putting any sort of ads in the app on my end and not sure about allowing forum-based ads either (depends on interest and being able to implement)
- Might be willing to allow the forum owner to display adds using an addon that can be worked with an approved by me and the API developer (basically maybe in the future)
- Don't plan to store any sort of information about your users on my end (including the forums they use).
- The only information that I'd have is what ever Google's Play Store gives to those who publish an app.
- There will be no "app login" needed to use the app, nor do I plan to sync user's forums currently
- Syncing might be a future feature (if demanded).
- Since I absolutely hate the way some apps promoted communities and allowed you to search for them! I'd make it so that they'd have to prove your URL or some similar method where it's given to the app by your forum or the end user.
- Won't be making any sort of "in-app forum directory"
- Might publish a list of forums who are using it (and opt-in) on a web site in the future (TBD)
- Don't plan on making an iOS version (sorry).
- Will likely allow third parties to use same API but if they are they will have to agree to a set of terms that prevents them from doing stuff that I am against (listed above)