Granting an app access to a single library

Dear @UNC,

I hope you're having a good day.

If by "a single library" you mean a specific SharePoint document library, then the answer is not directly through the standard app permission model.

Microsoft supports granting applications access to specific SharePoint sites by using the Sites.Selected permission model. With this approach, an application can be restricted to one or more specific SharePoint sites instead of receiving access to all sites in the tenant.

However, Sites.Selected operates at the site level, not at the individual document library level.

• Supported: App > Access to Site A only
• Not directly supported: App > Access only to Library X within Site A

Assuming SharePoint Online is available in your tenant and the necessary administrative permissions are available, Microsoft 365 Business Basic would generally not be the limiting factor in this scenario.

For reference: Granting access via Entra ID App-Only | Microsoft Learn

If your requirement is to isolate access to a single library, a common approach is to place that library in a dedicated SharePoint site and then grant the application access only to that site using Sites.Selected.

I hope this information helps point you in the right direction.

Warm regards,  

If the answer is helpful, please select "Yes, accept answer". If you have any questions or new updates, please feel free to comment below.