diff --git a/opax-mcp/server.py b/opax-mcp/server.py
index 10061ba..1fab9e0 100644
--- a/opax-mcp/server.py
+++ b/opax-mcp/server.py
@@ -14,6 +14,7 @@ from typing import Optional, Any
 app = FastAPI(title="opax-mcp", version="2.0.0")
 
 OPAX_BASE_URL = os.environ.get("OPAX_BASE_URL", "https://opax.vauco.no")
+OPAX_IAP_CLIENT_ID = os.environ.get("OPAX_IAP_CLIENT_ID", "")
 MCP_SECRET    = os.environ.get("MCP_SECRET", "")
 
 # Gitea
@@ -33,7 +34,7 @@ def _opax_identity_token() -> str:
     """Hent identity token for opax.vauco.no (Cloud Run IAP/IAM)."""
     metadata_url = (
         "http://metadata.google.internal/computeMetadata/v1/instance"
-        f"/service-accounts/default/identity?audience={OPAX_BASE_URL}&format=full"
+                    f"/service-accounts/default/identity?audience={OPAX_IAP_CLIENT_ID or OPAX_BASE_URL}&format=full"
     )
     try:
         resp = httpx.get(metadata_url, headers={"Metadata-Flavor": "Google"}, timeout=5)