Can I create a .NET application and let it live inside Office 365?

Question

I know I don't want an add-in to any existing Office 365 application.

I want to be able to develop a .net application that will be able to query multiple data sources and live inside of Office 365 to display data the way I code it to.

The data I will be querying lives in places like Active Directory, Dynamics AX, Sharepoint, etc.

Is this a thing that Office 365 is capable of doing? I'm unable to find examples of this (which makes me think no) but I am also unable to find a source explicitly saying you can't do this. This is not limited to HTML/JS, I want to be able to write back-end functionality.

Please help.

Answer 1

You can use Office Graph to query whatever data you want on Office 365, SharePoint, OneDrive.

The authentication will be done using OAuth and you can have your application running inside or outside Office 365.

You can install Office 365 API Tools for Visual Studio which will give you an option in VS called Add Connected Service, it asks you for the credentials and generate code that will do everything for you.

Here is more info about Office Graph

Answer 2

If by "living in Office 365" you mean you want to have your app listed in the App Launcher alongside Mail, Calendar, People, etc., then you can register your app with Azure AD to have it listed:

https://msdn.microsoft.com/en-us/office/office365/howto/connect-your-app-to-o365-app-launcher?f=255&MSPPError=-2147217396

Your web app can use JavaScript/HTML/CSS, and you can also have it use back-end functionality by using the ASP.NET Web API to perform your business logic and use the Graph API as well.