From 5477dbe74cd882b921de3dd052c31302b530f2fe Mon Sep 17 00:00:00 2001 From: mateo-berri <277851410+mateo-berri@users.noreply.github.com> Date: Sat, 19 Sep 2026 03:55:23 -0700 Subject: [PATCH] fix(responses): drop tool_search and local_shell in the chat completions bridge Hosted Responses API tools with no Chat Completions equivalent were forwarded verbatim, so Codex 0.140+ got a 400 from the provider on every turn. The bridge now drops tool_search and local_shell the same way it drops computer_use, image_generation, and shell, and also drops parallel_tool_calls when no chat tools remain, since chat completions only accepts it alongside tools --- .../transformation.py | 3 +- .../test_litellm_completion_responses.py | 115 ++++++++++++++++++ 2 files changed, 117 insertions(+), 1 deletion(-) diff --git a/litellm/responses/litellm_completion_transformation/transformation.py b/litellm/responses/litellm_completion_transformation/transformation.py index 1fd88998491..cf3075ee28d 100644 --- a/litellm/responses/litellm_completion_transformation/transformation.py +++ b/litellm/responses/litellm_completion_transformation/transformation.py @@ -466,6 +466,7 @@ class LiteLLMCompletionResponsesConfig: if not tools: litellm_completion_request.pop("tool_choice", None) litellm_completion_request.pop("tools", None) + litellm_completion_request.pop("parallel_tool_calls", None) # Responses API `Completed` events require usage, we pass `stream_options` to litellm.completion to include usage if stream is True: @@ -2036,7 +2037,7 @@ class LiteLLMCompletionResponsesConfig: if tool_type == "custom": converted: Final = convert_custom_tool_to_function_tool(tool) return ResponsesToolChatForm(chat_tools=() if converted is None else (converted,), web_search_options=None) - if tool_type in ("computer_use", "image_generation", "shell"): + if tool_type in ("computer_use", "image_generation", "local_shell", "shell", "tool_search"): verbose_logger.warning( "Dropping Responses API tool of type '%s': it has no Chat Completions " "equivalent and the target provider would reject the request.", diff --git a/tests/test_litellm/responses/litellm_completion_transformation/test_litellm_completion_responses.py b/tests/test_litellm/responses/litellm_completion_transformation/test_litellm_completion_responses.py index ff129b2e545..4cddc80450f 100644 --- a/tests/test_litellm/responses/litellm_completion_transformation/test_litellm_completion_responses.py +++ b/tests/test_litellm/responses/litellm_completion_transformation/test_litellm_completion_responses.py @@ -1248,6 +1248,45 @@ class TestFunctionCallTransformation: assert "tool_choice" not in result assert "tools" not in result + def test_parallel_tool_calls_dropped_when_no_chat_tools_remain(self) -> None: + transform: Final = LiteLLMCompletionResponsesConfig.transform_responses_api_request_to_chat_completion_request + codex_tool_search: Final = { + "type": "tool_search", + "execution": "client", + "description": "Searches over deferred tool metadata with BM25.", + "parameters": {"type": "object", "properties": {"query": {"type": "string"}}, "required": ["query"]}, + } + function_tool: Final = { + "type": "function", + "name": "get_goal", + "description": "Returns the current goal.", + "parameters": {"type": "object", "properties": {}}, + "strict": True, + } + + empty_tools_result: Final = transform( + model="azure/gpt-5.4-mini", + input="Reply with just the word pong.", + responses_api_request={"tools": [], "parallel_tool_calls": True}, + custom_llm_provider="azure", + ) + hosted_only_result: Final = transform( + model="azure/gpt-5.4-mini", + input="Reply with just the word pong.", + responses_api_request={"tools": [codex_tool_search], "parallel_tool_calls": True}, + custom_llm_provider="azure", + ) + function_tools_result: Final = transform( + model="azure/gpt-5.4-mini", + input="Reply with just the word pong.", + responses_api_request={"tools": [function_tool], "parallel_tool_calls": True}, + custom_llm_provider="azure", + ) + + assert "parallel_tool_calls" not in empty_tools_result + assert "parallel_tool_calls" not in hosted_only_result + assert function_tools_result["parallel_tool_calls"] is True + def test_function_call_without_call_id_fallback_to_id(self): """Test that function_call items can use 'id' field when 'call_id' is missing""" function_call_item = { @@ -1659,6 +1698,82 @@ class TestToolTransformation: assert len(result_tools) == 0 assert web_search_options is None + def test_transform_codex_tools_drops_hosted_tool_search(self) -> None: + codex_tools: Final = [ + { + "type": "function", + "name": "exec_command", + "description": "Runs a command in a PTY.", + "parameters": {"type": "object", "properties": {"cmd": {"type": "string"}}, "required": ["cmd"]}, + "strict": True, + }, + { + "type": "function", + "name": "write_stdin", + "description": "Writes characters to an existing session's stdin.", + "parameters": { + "type": "object", + "properties": {"session_id": {"type": "number"}, "chars": {"type": "string"}}, + "required": ["session_id", "chars"], + }, + "strict": True, + }, + { + "type": "custom", + "name": "apply_patch", + "description": "The `apply_patch` tool can be used to edit files.", + "format": { + "type": "grammar", + "syntax": "lark", + "definition": 'start: begin_patch hunk+ end_patch\nbegin_patch: "*** Begin Patch" LF\n', + }, + }, + { + "type": "tool_search", + "execution": "client", + "description": ( + "# Tool discovery\n\nSearches over deferred tool metadata with BM25 and exposes matching tools " + "for the next model call.\n\nYou have access to tools from the following sources:\n" + "- Multi-agent tools: Spawn and manage sub-agents.\nSome of the tools may not have been provided " + "to you upfront, and you should use this tool (`tool_search`) to search for the required tools. " + "For MCP tool discovery, always use `tool_search` instead of `list_mcp_resources` or " + "`list_mcp_resource_templates`." + ), + "parameters": { + "type": "object", + "properties": { + "limit": {"type": "number", "description": "Maximum number of tools to return. Defaults to 8."}, + "query": {"type": "string", "description": "Search query for deferred tools."}, + }, + "required": ["query"], + "additionalProperties": False, + }, + }, + {"type": "web_search", "external_web_access": False, "search_content_types": ["text", "image"]}, + ] + function_and_custom_count: Final = sum(1 for tool in codex_tools if tool["type"] in ("function", "custom")) + + ( + result_tools, + web_search_options, + ) = LiteLLMCompletionResponsesConfig.transform_responses_api_tools_to_chat_completion_tools(tools=codex_tools) + + assert not any(tool.get("type") == "tool_search" for tool in result_tools) + assert all(tool.get("type") == "function" for tool in result_tools) + assert len(result_tools) == function_and_custom_count + assert web_search_options is not None + + def test_transform_local_shell_tools_dropped(self) -> None: + ( + result_tools, + web_search_options, + ) = LiteLLMCompletionResponsesConfig.transform_responses_api_tools_to_chat_completion_tools( + tools=[{"type": "local_shell"}] + ) + + assert result_tools == [] + assert web_search_options is None + def test_transform_custom_tools_to_function_tools(self): """Test that custom (freeform/grammar) tools are converted to function tools""" custom_tool = {