diff --git a/cogstack.py b/cogstack.py
index 6bfb8b5..e6e2127 100644
--- a/cogstack.py
+++ b/cogstack.py
@@ -26,9 +26,8 @@ def __init__(self, hosts: List, username: Optional[str] = None, password: Option
                  api: bool = False, timeout: Optional[int]=60):
 
         if api:
-            api_username, api_password = self._check_auth_details(username, password)
             self.elastic = elasticsearch.Elasticsearch(hosts=hosts,
-                                                       api_key=(api_username, api_password),
+                                                       api_key=api_key,
                                                        verify_certs=False,
                                                        timeout=timeout)
         else:
diff --git a/credentials.py b/credentials.py
index c70eda5..62193a6 100644
--- a/credentials.py
+++ b/credentials.py
@@ -8,6 +8,7 @@
 username = None
 password = None
 
+api_key = None # Encoded api key issued by your cogstack administrator.
 
 # NLM authentication
 # The UMLS REST API requires a UMLS account for the authentication described below.