fix(responses): replay web_search_call input items that have no action

litellm/responses/litellm_completion_transformation/transformation.py

@@ -459,6 +459,15 @@ def _dropped_cache_control(_: object) -> None:
     return None
 
 
+def _replayed_web_search_call(input_item: Mapping[str, object]) -> ResponseFunctionWebSearch:
+    try:
+        return ResponseFunctionWebSearch.model_validate(input_item)
+    except ValidationError:
+        # Azure and Codex replay web_search_call items without the SDK-required `action`;
+        # the item only becomes replay text, so keep it as sent instead of failing the turn.
+        return ResponseFunctionWebSearch.model_construct(None, **input_item)
+
+
 def _without_cache_control_key(item: object) -> object:
     if not isinstance(item, dict):
         return item
@@ -2062,7 +2071,7 @@ class LiteLLMCompletionResponsesConfig:
         - ItemReference
         """
         if input_item.get("type") == "web_search_call":
-            search: Final = ResponseFunctionWebSearch.model_validate(input_item)
+            search: Final = _replayed_web_search_call(input_item)
             return [
                 GenericChatCompletionMessage(
                     role="assistant",

tests/unit/responses/litellm_completion_transformation/test_litellm_completion_responses.py

@@ -5062,6 +5062,22 @@ class TestHostedWebSearchReplay:
         assert replayed == search
         assert input_item == original
 
+    def test_replays_search_without_action(self) -> None:
+        # Azure and Codex replay web_search_call items without the SDK-required `action`.
+        input_item: Final = {"type": "web_search_call", "id": "ws_no_action", "status": "completed"}
+
+        messages: Final = (
+            LiteLLMCompletionResponsesConfig._transform_responses_api_input_item_to_chat_completion_message(
+                input_item=input_item
+            )
+        )
+
+        assert len(messages) == 1
+        assert messages[0]["role"] == "assistant"
+        content: Final = messages[0].get("content")
+        assert isinstance(content, str)
+        assert json.loads(content[content.index("{") :]) == input_item
+
     @pytest.mark.parametrize("order", ((0, 1, 2, 3), (1, 0, 3, 2), (1, 3, 0, 2)))
     @pytest.mark.parametrize("modify_params", (False, True))
     @pytest.mark.parametrize("structured_content", (False, True))