Hi @ashfire ,

It seems that your service principal is getting a an access token at Account level, but model serving endpoints live at the workspace level. In databricks you have 2 separate API: 

- Account level API

- Workspace Level

As you can see at below screen - the serving endpoint lives at workspace level so it expects access token generated at that level.

Here you can read more details about the difference between those two and how to generate workspace level access token

Authorizing access to Azure Databricks resources - Azure Databricks | Microsoft Learn