fix(llm): handle LiteLLM supports_response_schema introspection failure gracefully (#6412)

Author: Hasnaathussain

lib/crewai/src/crewai/llm.py

@@ -2384,16 +2384,25 @@ def _validate_call_params(self) -> None:
         Note: This validation only applies to the litellm fallback path.
         Native providers have their own validation.
         """
+        if self.response_format is None:
+            return
+
         if not _ensure_litellm() or supports_response_schema is None:
             # When litellm is not available, skip validation
             # (this path should only be reached for litellm fallback models)
             return
 
         provider = self._get_custom_llm_provider()
-        if self.response_format is not None and not supports_response_schema(
-            model=self.model,
-            custom_llm_provider=provider,
-        ):
+        try:
+            is_supported = supports_response_schema(
+                model=self.model,
+                custom_llm_provider=provider,
+            )
+        except Exception as e:
+            logger.debug(f"LiteLLM supports_response_schema check failed: {e!s}")
+            is_supported = True
+
+        if not is_supported:
             raise ValueError(
                 f"The model {self.model} does not support response_format for provider '{provider}'. "
                 "Please remove response_format or use a supported model."

lib/crewai/tests/test_llm.py

@@ -1177,3 +1177,13 @@ async def _ret(*args, **kwargs):
     assert isinstance(result, list)
     assert len(result) == 1
     assert result[0].function.name == "search"
+
+
+def test_validate_call_params_handles_introspection_error():
+    """Verify that _validate_call_params gracefully handles LiteLLM introspection errors without crashing."""
+    llm = LLM(model="custom/unsupported-model", is_litellm=True, response_format={"type": "json_object"})
+
+    with patch("crewai.llm.supports_response_schema", side_effect=Exception("Introspection error")):
+        # Should not raise exception
+        llm._validate_call_params()
+