Sites.Selected MS Graph API permissions were introduced by Microsoft in March 2021. It was a good move towards site-level access for non-interactive (daemon) applications, but still developers were limited with only what MS Graph API provides for SharePoint. SharePoint CSOM and REST API still provides much more than MS Graph API.
So developers had to use AppInv.aspx at site level to provide ACS-based permissions to their apps to be able to use SharePoint CSOM and REST APIs. The bad news is ACS-based permissions have some downsides so some SharePoint/m365/security engineers consider them legacy and deprecated. But if we decide to disable SharePoint App-only service principals – all apps with ACS-based permissions provided via AppInv.aspx will stop working.
2021: Microsoft Graph Sites.Selected API
Recently Microsoft introduced Sites.Selected SharePoint API permissions for registered Azure Apps! So from now developers should be fully happy with API permissions provided in Azure (without SharePoint ACS-based permissions).
2022: SharePoint Sites.Selected API
Why is this so important? Because this should allow us to be able to switch from ACS based permissions provided in SharePoint via AppInv.aspx to Azure-provided permissions and as a consequence – disable SharePoint-Apps only principal (‘set-spotenant -DisableCustomAppAuthentication $true’).
Why we are eager to disable Custom App Authentication in SharePoint? Simply say, SharePoint App-only service principals are not trackable (they all appeared as a “email@example.com” id in all logs) and hard to manage (there is no way to get list of existing/registered SP app-only service principals, sites and their owners) – see more in this article.
So, SharePoint Sites.Selected application API permissions provided in Azure is a significient step to make Microsoft 365 SharePoint environment more secure and manageble.
The code must run without user interaction (unattended, aka daemon app). Sometimes this is also called “SharePoint Automation”.
The solution is based on a new Graph API feature – Sites.Selected and a classic SP-Only app.
Register an Azure App and configure it as usual. Select API Permissions blade and add two permissions: – Microsoft Graph -> Applications Permissions -> “sites.selected” – SharePoint -> Applications Permissions -> “sites.selected“
Request “Grant admin consent” from a tenant/global admin
Request SharePoint admin to run PowerShell code (e.g. this one) to assign proper permissions to your azure app for a specific site collection (consider site owner consent)
(optionally) Provide SharePoint API permissions: (require Site Collection Owner/Admin account) – use https://YourTenant.sharepoint.com/teams/YourSite/_layouts/15/appinv.aspx to add SharePoint API permissions to your app. E.g. full control permissions to site collection would be
Sites.Selected API MS Graph permissions was introduced by Microsoft in 2021. It was a huge step forward, but still devs were limited with MS Graph API against SharePoint. So devs had to use AppInv at site level to provide ACS permissions to their apps to use SharePoint CSOM and REST APIs. Recently Microsoft introduced Sites.Selected SharePoint API permissions for registered Azure Apps! So now devs should be fully happy without ACS-based permissions AppInv.aspx. (See more here on disabling SP Apps Only SPNs)