diff --git a/apps/api/src/api/tool_instances.py b/apps/api/src/api/tool_instances.py
index 568e5fe..9b0d93c 100644
--- a/apps/api/src/api/tool_instances.py
+++ b/apps/api/src/api/tool_instances.py
@@ -736,17 +736,16 @@ async def start_instance(
 
     # Get tool type for default port
     tool_type = await session.get(ToolType, instance.tool_type_id)
-    if not tool_type or not tool_type.default_port:
-        logger.error("Tool type %s has no default_port configured. Cannot create tunnel.", 
-                    instance.tool_type_id)
+    if not tool_type:
+        logger.error("Tool type %s not found", instance.tool_type_id)
         instance.status = "error"
         await session.commit()
         return {
             "status": "error",
-            "error": f"Tool type '{tool_type.name if tool_type else 'unknown'}' has no port configured",
+            "error": f"Tool type '{instance.tool_type_id}' not found",
         }
     
-    instance_port = tool_type.default_port
+    instance_port = tool_type.default_port or 0
     logger.info("Tool type for instance %s: name=%s, default_port=%s, interface_type=%s", 
                 instance.id, tool_type.name, instance_port, tool_type.interface_type)