Having Troubles Getting OnlineMCP Tools

[MartinYTSo]

There is an error with regards to the integration of langchain_mcp_adapters and online MCP tools

Lets say I wanted to use this Time MCP server: https://mcp.so/server/time/modelcontextprotocol

from langchain_mcp_adapters.client import MultiServerMCPClient
client = MultiServerMCPClient(
    {
        "time": {
        "transport": "stdio",
        "command": "uvx",
        "args": [
            "mcp-server-time",
            "--local-timezone=America/New_York"
        ]
        }
    }
)

tools =  await client.get_tools()

I get this error:

---------------------------------------------------------------------------
NotImplementedError                       Traceback (most recent call last)
File c:\Users\epicr\OneDrive\Documents\GitHub\lca-lc-foundations\.venv\Lib\site-packages\mcp\os\win32\utilities.py:169, in create_windows_process(command, args, env, errlog, cwd)
    167 try:
    168     # First try using anyio with Windows-specific flags to hide console window
--> [169](file:///C:/Users/epicr/OneDrive/Documents/GitHub/lca-lc-foundations/.venv/Lib/site-packages/mcp/os/win32/utilities.py:169)     process = await anyio.open_process(
    170         [command, *args],
    171         env=env,
    172         # Ensure we don't create console windows for each process
    173         creationflags=subprocess.CREATE_NO_WINDOW  # type: ignore
    174         if hasattr(subprocess, "CREATE_NO_WINDOW")
    175         else 0,
    176         stderr=errlog,
    177         cwd=cwd,
    178     )
    179 except NotImplementedError:
    180     # If Windows doesn't support async subprocess creation, use fallback

File c:\Users\epicr\OneDrive\Documents\GitHub\lca-lc-foundations\.venv\Lib\site-packages\anyio\_core\_subprocesses.py:190, in open_process(command, stdin, stdout, stderr, cwd, env, startupinfo, creationflags, start_new_session, pass_fds, user, group, extra_groups, umask)
    188     kwargs["umask"] = umask
--> [190](file:///C:/Users/epicr/OneDrive/Documents/GitHub/lca-lc-foundations/.venv/Lib/site-packages/anyio/_core/_subprocesses.py:190) return await get_async_backend().open_process(
    191     command,
    192     stdin=stdin,
    193     stdout=stdout,
    194     stderr=stderr,
...
    370     return self._original_stdstream_copy
    371 msg = "fileno"
--> [372](file:///C:/Users/epicr/OneDrive/Documents/GitHub/lca-lc-foundations/.venv/Lib/site-packages/ipykernel/iostream.py:372) raise io.UnsupportedOperation(msg)

UnsupportedOperation: fileno

This is not the only error, every time I use stdio I get the UnsupportedOperation: fileno

If I substituted tools = await client.get_tools() for tools = client.get_tools() and then passed it on to create_agent:

agent = create_agent(
    model="gpt-5-nano",
    tools=tools,
    checkpointer=InMemorySaver()
)

It throws me an error:

from langchain.agents import create_agent
from langgraph.checkpoint.memory import InMemorySaver  
agent = create_agent(
    model="gpt-5-nano",
    tools=tools,
    checkpointer=InMemorySaver()
)