diff --git a/src/pyra/chat/session.py b/src/pyra/chat/session.py
index 0f61a87..b217d5c 100644
--- a/src/pyra/chat/session.py
+++ b/src/pyra/chat/session.py
@@ -257,8 +257,9 @@ def _call_ai(
         "model": f"{provider.litellm_prefix}{cfg.ai.model}",
         "api_key": api_key,
     }
-    if cfg.ai.base_url:
-        base_kwargs["api_base"] = cfg.ai.base_url
+    effective_base_url = cfg.ai.base_url or provider.base_url
+    if effective_base_url:
+        base_kwargs["api_base"] = effective_base_url
 
     litellm.suppress_debug_info = True