diff --git a/libs/agent/agent/providers/uitars/clients/oaicompat.py b/libs/agent/agent/providers/uitars/clients/oaicompat.py
index 1b512997..423b1d3a 100644
--- a/libs/agent/agent/providers/uitars/clients/oaicompat.py
+++ b/libs/agent/agent/providers/uitars/clients/oaicompat.py
@@ -190,25 +190,21 @@ class OAICompatClient(BaseUITarsClient):
                     response_text = await response.text()
                     logger.debug(f"Response content: {response_text}")
                     
+                    # if 503, then the endpoint is still warming up
+                    if response.status == 503:
+                        logger.error(f"Endpoint is still warming up, please try again later")
+                        raise Exception(f"Endpoint is still warming up: {response_text}")
+                    
                     # Try to parse as JSON if the content type is appropriate
                     if "application/json" in response.headers.get('Content-Type', ''):
                         response_json = await response.json()
                     else:
                         raise Exception(f"Response is not JSON format")
-                        # # Optionally try to parse it anyway
-                        # try:
-                        #     import json
-                        #     response_json = json.loads(response_text)
-                        # except json.JSONDecodeError as e:
-                        #     print(f"Failed to parse response as JSON: {e}")
 
                     if response.status != 200:
-                        error_msg = response_json.get("error", {}).get(
-                            "message", str(response_json)
-                        )
-                        logger.error(f"Error in API call: {error_msg}")
-                        raise Exception(f"API error: {error_msg}")
-
+                        logger.error(f"Error in API call: {response_text}")
+                        raise Exception(f"API error: {response_text}")
+                    
                     return response_json
 
         except Exception as e: