diff --git a/biochatter/llm_connect.py b/biochatter/llm_connect.py
index 9c2bba6c..e375079f 100644
--- a/biochatter/llm_connect.py
+++ b/biochatter/llm_connect.py
@@ -1167,8 +1167,8 @@ def _primary_query(self):
         as context. Correct the response if necessary.
 
         Returns:
-            tuple: A tuple containing the response from the Anthropic API and the
-                token usage.
+            tuple: A tuple containing the response from the Anthropic API and
+                the token usage.
         """
         try:
             history = self._create_history()
@@ -1319,6 +1319,7 @@ def __init__(
         prompts: dict,
         correct: bool = False,
         split_correction: bool = False,
+        base_url: str = None,
     ):
         """
         Connect to OpenAI's GPT API and set up a conversation with the user.
@@ -1333,6 +1334,9 @@ def __init__(
             split_correction (bool): Whether to correct the model output by
                 splitting the output into sentences and correcting each
                 sentence individually.
+
+            base_url (str): Optional OpenAI base_url value to use custom
+                endpoint URL instead of default
         """
         super().__init__(
             model_name=model_name,
@@ -1340,7 +1344,7 @@ def __init__(
             correct=correct,
             split_correction=split_correction,
         )
-
+        self.base_url = base_url
         self.ca_model_name = "gpt-3.5-turbo"
         # TODO make accessible by drop-down
 
@@ -1359,6 +1363,7 @@ def set_api_key(self, api_key: str, user: str) -> bool:
         """
         client = openai.OpenAI(
             api_key=api_key,
+            base_url=self.base_url,
         )
         self.user = user
 
@@ -1368,11 +1373,13 @@ def set_api_key(self, api_key: str, user: str) -> bool:
                 model_name=self.model_name,
                 temperature=0,
                 openai_api_key=api_key,
+                base_url=self.base_url,
             )
             self.ca_chat = ChatOpenAI(
                 model_name=self.ca_model_name,
                 temperature=0,
                 openai_api_key=api_key,
+                base_url=self.base_url,
             )
             if user == "community":
                 self.usage_stats = get_stats(user=user)