diff --git a/backend/igny8_core/ai/tasks.py b/backend/igny8_core/ai/tasks.py
index 98faf489..40f1000b 100644
--- a/backend/igny8_core/ai/tasks.py
+++ b/backend/igny8_core/ai/tasks.py
@@ -10,7 +10,7 @@ logger = logging.getLogger(__name__)
 
 
 @shared_task(bind=True, max_retries=3)
-def run_ai_task(self, function_name: str, payload: dict, account_id: int = None):
+def run_ai_task(self, function_name: str, payload: dict, account_id: int):
     """
     Single Celery entrypoint for all AI functions.
     Dynamically loads and executes the requested function.
@@ -18,7 +18,10 @@ def run_ai_task(self, function_name: str, payload: dict, account_id: int = None)
     Args:
         function_name: Name of the AI function (e.g., 'auto_cluster')
         payload: Function-specific payload
-        account_id: Account ID for account isolation
+        account_id: Account ID for account isolation (required)
+    
+    Raises:
+        Returns error dict if account_id not provided or account not found
     """
     logger.info("=" * 80)
     logger.info(f"run_ai_task STARTED: {function_name}")
@@ -29,14 +32,28 @@ def run_ai_task(self, function_name: str, payload: dict, account_id: int = None)
     logger.info("=" * 80)
     
     try:
-        # Get account
-        account = None
-        if account_id:
-            from igny8_core.auth.models import Account
-            try:
-                account = Account.objects.get(id=account_id)
-            except Account.DoesNotExist:
-                logger.warning(f"Account {account_id} not found")
+        # Validate account_id is provided
+        if not account_id:
+            error_msg = "account_id is required for AI task execution"
+            logger.error(f"[run_ai_task] {error_msg}")
+            return {
+                'success': False,
+                'error': error_msg,
+                'error_type': 'ConfigurationError'
+            }
+        
+        # Get account and validate it exists
+        from igny8_core.auth.models import Account
+        try:
+            account = Account.objects.get(id=account_id)
+        except Account.DoesNotExist:
+            error_msg = f"Account {account_id} not found"
+            logger.error(f"[run_ai_task] {error_msg}")
+            return {
+                'success': False,
+                'error': error_msg,
+                'error_type': 'AccountNotFound'
+            }
         
         # Get function from registry
         fn = get_function_instance(function_name)