Provide the ability to write to Managed Metadata via app-only policy
App-only policy in the SharePoint App Model is very restricted regarding Taxonomy operations. Even if an app is granted full control over the tenant, it lacks the permission to do anything but read operations on Taxonomy. Please provide the ability to create Groups, Term Sets and terms using app-only policy.
Great news – We are currently working on documentation and guidance around this option.
Usage of app@sharepoint is supported option to enable write operations for the Managed Metadata with app-only policy.
Official documentation will be updated in upcoming days and we’ll close this item as that will happen. Thanks everyone for your input and persistence around this.
Derek Gusoff commented
I've discovered that you can actually do this by putting "app@sharepoint" in the term store administrators group.
Gabriel Smoljár commented
I'd even call this a bug. In Azure AD you can grant "Read and Write Managed Metadata" app-only permissions to your app. But as you say, it doesn't work.