Connecting Power BI to Deltek Vantagepoint API

Hi tsimpkins , Thank you for reaching out to the Microsoft Community Forum.

Vantagepoint’s API uses a strict OAuth 2.0 flow through Deltek’s identity service and this is where the difficulty comes from. Power Query can technically make HTTP calls, but it is not well suited to handling custom OAuth token exchanges, redirects and refresh logic unless the service is natively supported by Power BI. That is why attempts to generate and reuse a bearer token purely in M code usually end in cryptic errors or break once you try to refresh in the Power BI Service.

In practice, there are only two approaches that work reliably. The first is to place a very small intermediary (for example, an Azure Function or Logic App) that handles the OAuth handshake with Vantagepoint, caches the bearer token and exposes a simple REST endpoint for Power BI to call. From Power BI’s perspective this becomes a normal API call with a static header, which refreshes cleanly and predictably. The second option is to build a custom Power BI connector, where you can properly implement the OAuth flow and token refresh; this aligns much better with how Deltek expects clients to authenticate.