[langchain] fix OpenAIAssistantRunnable.create_assistant (#19081)

- **Description:** OpenAI assistants support some pre-built tools (e.g.,
`"retrieval"` and `"code_interpreter"`) and expect these as `{"type":
"code_interpreter"}`. This may have been upset by
https://github.com/langchain-ai/langchain/pull/18935
- **Issue:** https://github.com/langchain-ai/langchain/issues/19057

libs/langchain/langchain/agents/openai_assistant/base.py

@@ -3,12 +3,23 @@ from __future__ import annotations
 import json
 from json import JSONDecodeError
 from time import sleep
-from typing import TYPE_CHECKING, Any, Dict, List, Optional, Sequence, Tuple, Union
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Callable,
+    Dict,
+    List,
+    Optional,
+    Sequence,
+    Tuple,
+    Type,
+    Union,
+)
 
 from langchain_core.agents import AgentAction, AgentFinish
 from langchain_core.callbacks import CallbackManager
 from langchain_core.load import dumpd
-from langchain_core.pydantic_v1 import Field, root_validator
+from langchain_core.pydantic_v1 import BaseModel, Field, root_validator
 from langchain_core.runnables import RunnableConfig, RunnableSerializable, ensure_config
 from langchain_core.tools import BaseTool
 from langchain_core.utils.function_calling import convert_to_openai_tool
@@ -76,6 +87,32 @@ def _get_openai_async_client() -> openai.AsyncOpenAI:
         ) from e
 
 
+def _is_assistants_builtin_tool(
+    tool: Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool],
+) -> bool:
+    """Determine if tool corresponds to OpenAI Assistants built-in."""
+    assistants_builtin_tools = ("code_interpreter", "retrieval")
+    return (
+        isinstance(tool, dict)
+        and ("type" in tool)
+        and (tool["type"] in assistants_builtin_tools)
+    )
+
+
+def _get_assistants_tool(
+    tool: Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool],
+) -> Dict[str, Any]:
+    """Convert a raw function/class to an OpenAI tool.
+
+    Note that OpenAI assistants supports several built-in tools,
+    such as "code_interpreter" and "retrieval."
+    """
+    if _is_assistants_builtin_tool(tool):
+        return tool  # type: ignore
+    else:
+        return convert_to_openai_tool(tool)
+
+
 OutputType = Union[
     List[OpenAIAssistantAction],
     OpenAIAssistantFinish,
@@ -210,7 +247,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
         assistant = client.beta.assistants.create(
             name=name,
             instructions=instructions,
-            tools=[convert_to_openai_tool(tool) for tool in tools],  # type: ignore
+            tools=[_get_assistants_tool(tool) for tool in tools],  # type: ignore
             model=model,
             file_ids=kwargs.get("file_ids"),
         )
@@ -328,7 +365,7 @@ class OpenAIAssistantRunnable(RunnableSerializable[Dict, OutputType]):
             AsyncOpenAIAssistantRunnable configured to run using the created assistant.
         """
         async_client = async_client or _get_openai_async_client()
-        openai_tools = [convert_to_openai_tool(tool) for tool in tools]
+        openai_tools = [_get_assistants_tool(tool) for tool in tools]
         assistant = await async_client.beta.assistants.create(
             name=name,
             instructions=instructions,

libs/langchain/tests/unit_tests/agents/test_openai_assistant.py

@@ -1,8 +1,20 @@
+from functools import partial
+from typing import Any
+from unittest.mock import AsyncMock, MagicMock, patch
+
 import pytest
 
 from langchain.agents.openai_assistant import OpenAIAssistantRunnable
 
 
+def _create_mock_client(*args: Any, use_async: bool = False, **kwargs: Any) -> Any:
+    client = AsyncMock() if use_async else MagicMock()
+    mock_assistant = MagicMock()
+    mock_assistant.id = "abc123"
+    client.beta.assistants.create.return_value = mock_assistant  # type: ignore
+    return client
+
+
 @pytest.mark.requires("openai")
 def test_user_supplied_client() -> None:
     import openai
@@ -19,3 +31,34 @@ def test_user_supplied_client() -> None:
     )
 
     assert assistant.client == client
+
+
+@pytest.mark.requires("openai")
+@patch(
+    "langchain.agents.openai_assistant.base._get_openai_client",
+    new=partial(_create_mock_client, use_async=False),
+)
+def test_create_assistant() -> None:
+    assistant = OpenAIAssistantRunnable.create_assistant(
+        name="name",
+        instructions="instructions",
+        tools=[{"type": "code_interpreter"}],
+        model="",
+    )
+    assert isinstance(assistant, OpenAIAssistantRunnable)
+
+
+@pytest.mark.requires("openai")
+@patch(
+    "langchain.agents.openai_assistant.base._get_openai_async_client",
+    new=partial(_create_mock_client, use_async=True),
+)
+async def test_acreate_assistant() -> None:
+    assistant = await OpenAIAssistantRunnable.acreate_assistant(
+        name="name",
+        instructions="instructions",
+        tools=[{"type": "code_interpreter"}],
+        model="",
+        client=_create_mock_client(),
+    )
+    assert isinstance(assistant, OpenAIAssistantRunnable)