Error in LangChainToolAdapter GoogleDriveSearchTool: Unable to generate pydantic-core schema

[dnascimento]

What happened?

Describe the bug
The pytdantic-core schema seems to be failing with tools like GoogleDriveSearchTool. What am I missing here?

pydantic==2.10.6
pydantic-settings==2.8.1
pydantic_core==2.27.2
langchain==0.3.24
langchain-aws==0.2.18
langchain-community==0.3.22
langchain-core==0.3.55
langchain-experimental==0.3.4
langchain-text-splitters==0.3.8
autogen-agentchat==0.4.9.2
autogen-core==0.5.4
autogen-ext==0.5.4

ERROR:root:An error occurred: Unable to generate pydantic-core schema for <class 'langchain_core.callbacks.manager.CallbackManagerForToolRun'>. Set `arbitrary_types_allowed=True` in the model_config to ignore this error or implement `__get_pydantic_core_schema__` on your type to fully support it.

If you got this error by calling handler(<some type>) within `__get_pydantic_core_schema__` then you likely need to call `handler.generate_schema(<some type>)` since we do not call `__get_pydantic_core_schema__` on `<some type>` otherwise to avoid infinite recursion.

For further information visit https://errors.pydantic.dev/2.11/u/schema-for-unknown-type
Traceback (most recent call last):
  File "tests/tool_langchain.py", line 112, in <module>
    asyncio.run(main())
  File "/usr/lib/python3.12/asyncio/runners.py", line 194, in run
    return runner.run(main)
           ^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/asyncio/base_events.py", line 687, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "tests/tool_langchain.py", line 80, in main
    autogen_tool = LangChainToolAdapter(drive_tool)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/autogen_ext/tools/langchain/_langchain_adapter.py", line 175, in __init__
    args_type = create_model(f"{name}Args", **fields)  # type: ignore
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/main.py", line 1772, in create_model
    return meta(
           ^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_model_construction.py", line 237, in __new__
    complete_model_class(
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_model_construction.py", line 597, in complete_model_class
    schema = gen_schema.generate_schema(cls)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 706, in generate_schema
    schema = self._generate_schema_inner(obj)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 984, in _generate_schema_inner
    return self._model_schema(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 817, in _model_schema
    {k: self._generate_md_field_schema(k, v, decorators) for k, v in fields.items()},
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1186, in _generate_md_field_schema
    common_field = self._common_field_schema(name, field_info, decorators)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1352, in _common_field_schema
    schema = self._apply_annotations(
             ^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 2264, in _apply_annotations
    schema = get_inner_schema(source_type)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_schema_generation_shared.py", line 83, in __call__
    schema = self._handler(source_type)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 2246, in inner_handler
    schema = self._generate_schema_inner(obj)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 989, in _generate_schema_inner
    return self.match_type(obj)
           ^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1103, in match_type
    return self._match_generic_type(obj, origin)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1126, in _match_generic_type
    return self._union_schema(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1414, in _union_schema
    choices.append(self.generate_schema(arg))
                   ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 706, in generate_schema
    schema = self._generate_schema_inner(obj)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 989, in _generate_schema_inner
    return self.match_type(obj)
           ^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 1107, in match_type
    return self._unknown_type_schema(obj)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "venv/lib/python3.12/site-packages/pydantic/_internal/_generate_schema.py", line 634, in _unknown_type_schema
    raise PydanticSchemaGenerationError(
pydantic.errors.PydanticSchemaGenerationError: Unable to generate pydantic-core schema for <class 'langchain_core.callbacks.manager.CallbackManagerForToolRun'>. Set `arbitrary_types_allowed=True` in the model_config to ignore this error or implement `__get_pydantic_core_schema__` on your type to fully support it.

If you got this error by calling handler(<some type>) within `__get_pydantic_core_schema__` then you likely need to call `handler.generate_schema(<some type>)` since we do not call `__get_pydantic_core_schema__` on `<some type>` otherwise to avoid infinite recursion.

For further information visit https://errors.pydantic.dev/2.11/u/schema-for-unknown-type

To Reproduce

import asyncio
import os
from autogen_ext.tools.langchain import LangChainToolAdapter
from autogen_ext.models.openai import OpenAIChatCompletionClient
from autogen_agentchat.messages import TextMessage
from autogen_agentchat.agents import AssistantAgent
from autogen_agentchat.ui import Console
from autogen_core import CancellationToken
from google.oauth2 import service_account
from langchain_googledrive.tools.google_drive.tool import GoogleDriveSearchTool
from langchain_googledrive.utilities.google_drive import GoogleDriveAPIWrapper
import logging

async def main() -> None:
    # Step 1: Authenticate with service account
    SERVICE_ACCOUNT_FILE = "./service-account.json"
    SCOPES = ["https://www.googleapis.com/auth/drive.readonly"]

    try:
        credentials = service_account.Credentials.from_service_account_file(
            SERVICE_ACCOUNT_FILE, scopes=SCOPES
        )
        logging.info(f"Using service account: {credentials.service_account_email}")

        # Initialize Google Drive API wrapper
        folder_id = "root"
        drive_wrapper = GoogleDriveAPIWrapper(
            credentials=credentials,
            folder_id=folder_id,
            num_results=20,
            template="gdrive-query-in-folder",
            mode="documents-markdown"
        )
        
        # Create the Google Drive search tool
        drive_tool = GoogleDriveSearchTool(api_wrapper=drive_wrapper)

        print(drive_tool.invoke("my_docs"))
        
        # # Wrap the LangChain tool with Autogen adapter
        autogen_tool = LangChainToolAdapter(drive_tool)
        
        # Initialize the model client
        model_client = OpenAIChatCompletionClient(
            model="gpt-4",
            api_key=os.getenv("OPENAI_API_KEY"),
            model_config={"arbitrary_types_allowed": True}
        )
        
        # Create the assistant agent with the Google Drive tool
        agent = AssistantAgent(
            "assistant",
            tools=[autogen_tool],
            model_client=model_client,
            system_message="You can search for files in Google Drive using the provided tool."
        )
        
        await Console(
            agent.on_messages_stream(
                [TextMessage(content="Tell me about the user", source="user")],
                CancellationToken()
            )
        )

    except Exception as e:
        logging.error(f"An error occurred: {str(e)}")
        raise

if __name__ == "__main__":
    logging.info("Starting Google Drive search tool")
    asyncio.run(main())
    logging.info("Done")

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
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Additional context
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Which packages was the bug in?

Python Extensions (autogen-ext)

AutoGen library version.

Python 0.5.4

Other library version.

No response

Model used

gpt-4

Model provider

OpenAI

Other model provider

No response

Python version

3.12

.NET version

None

Operating system

Ubuntu