diff --git a/core/business_manager.py b/core/business_manager.py
index 62a5578..4498be4 100644
--- a/core/business_manager.py
+++ b/core/business_manager.py
@@ -9,6 +9,10 @@
 
 import yaml
 
+API_KEY = os.getenv('OPENAI_API_KEY')
+if not API_KEY:
+    raise ValueError('OPENAI_API_KEY environment variable is missing')
+
 logger = logging.getLogger(__name__)