backend/config/main.py

@@ -19,7 +19,8 @@ class Config(BaseSettings):
     HELPER_ID: str = ''
 
     model_config = SettingsConfigDict(
-        env_file=('config/.env', 'config/.env.dev', 'config/.env.prod')
+        env_file=('config/.env', 'config/.env.dev', 'config/.env.prod'),
+        extra='ignore',
     )
 
 

backend/tests/unit/test_config.py

@@ -0,0 +1,5 @@
+from config.main import Config
+
+
+def test_config_ignores_extra_environment_fields():
+    assert Config.model_config.get('extra') == 'ignore'