diff --git a/nanobot/providers/litellm_provider.py b/nanobot/providers/litellm_provider.py
index 9d76c2a..dd50ed9 100644
--- a/nanobot/providers/litellm_provider.py
+++ b/nanobot/providers/litellm_provider.py
@@ -132,6 +132,10 @@ class LiteLLMProvider(LLMProvider):
         # Apply model-specific overrides (e.g. kimi-k2.5 temperature)
         self._apply_model_overrides(model, kwargs)
         
+        # Pass api_key directly — more reliable than env vars alone
+        if self.api_key:
+            kwargs["api_key"] = self.api_key
+        
         # Pass api_base for custom endpoints
         if self.api_base:
             kwargs["api_base"] = self.api_base