fix(vertex): don't error if project_id couldn't be loaded if it was a…

…lready explicitly given (#513)

src/anthropic/lib/vertex/_auth.py

@@ -15,14 +15,17 @@
 # cause synchronous blocking issues.
 
 
-def load_auth() -> tuple[Credentials, str]:
+def load_auth(*, project_id: str | None) -> tuple[Credentials, str]:
     from google.auth.transport.requests import Request  # type: ignore[import-untyped]
 
-    credentials, project_id = google_auth.default(
+    credentials, loaded_project_id = google_auth.default(
         scopes=["https://www.googleapis.com/auth/cloud-platform"],
     )
     credentials.refresh(Request())
 
+    if not project_id:
+        project_id = loaded_project_id
+
     if not project_id:
         raise ValueError("Could not resolve project_id")
 

src/anthropic/lib/vertex/_client.py

@@ -180,7 +180,7 @@ def _ensure_access_token(self) -> str:
             return self.access_token
 
         if not self._credentials:
-            self._credentials, project_id = load_auth()
+            self._credentials, project_id = load_auth(project_id=self.project_id)
             if not self.project_id:
                 self.project_id = project_id
         else:
@@ -267,7 +267,7 @@ async def _ensure_access_token(self) -> str:
             return self.access_token
 
         if not self._credentials:
-            self._credentials, project_id = await asyncify(load_auth)()
+            self._credentials, project_id = await asyncify(load_auth)(project_id=self.project_id)
             if not self.project_id:
                 self.project_id = project_id
         else: