AIError.authorizationRequired from an MCP server
A hosted MCP server needs an OAuth sign-in that could not be refreshed.
Symptom
AIError.authorizationRequired(url:) when listing or calling MCP tools.
Why it happens
The server returned a 401 and the session had no token, or had one it could not refresh. The URL in the error is the sign-in page.
This is the normal first-run path for a hosted server, not necessarily a failure.
Fix
Open the URL, then hand the redirect back:
let tokens = try await auth.complete(callbackURL: redirect)If it recurs on every run, your MCPOAuthClientProvider is not persisting
tokens and client registration. Both need to survive a relaunch.
If sign-in itself fails, the usual cause is saveState / state left as the
no-op defaults, which makes callback verification silently pass and then fail
later.