René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"support logging to stderr in Jupyter Notebook Environments.","articleBody":"**Is your feature request related to a problem? Please describe.**\nI want to make mcp python-sdk jupyter notebook compatible. When running in a notebook environment, MCP work but do not output stderr as it does normally.\n\nFor instance in jupyter notebook:\n\n```python\nimport mcp\nimport os\nfrom mcp.client.stdio import stdio_client\n\nserverparams = mcp.StdioServerParameters(\n    command=\"uv\",\n    args=[\"--quiet\", \"run\", \"../src/echo.py\"],\n    env={\"UV_PYTHON\": \"3.12\", **os.environ},\n)\n\nasync with stdio_client(serverparams) as (read, write):\n    async with mcp.ClientSession(read, write) as session:\n        await session.initialize()\n        tools = await session.list_tools()\n        print(tools)\n```\nOutputs:\n```\nmeta=None nextCursor=None tools=[Tool(name='echo_tool', description='Echo the input text\\n\\n    Args:\\n        text (str): The text to echo\\n\\n    Returns:\\n        str: The echoed text\\n    ', inputSchema={'properties': {'text': {'title': 'Text', 'type': 'string'}}, 'required': ['text'], 'title': 'echo_toolArguments', 'type': 'object'})]\n```\n\nwhile running the server without jupyter notebook:\n\n```bash\n❯ uv run --quiet src/echo.py\nstarting echo server\n```\n\nstderr is correctly displayed.\n\nThis is a big problem mostly because if the server is crashing or the command is wrong you have no way to know what's wrong: nothing is logged and the jupyter notebook cell just hangs.\n\n**Describe the solution you'd like**\nI found the culprit being the use of:\n\n```python \nprocess = await anyio.open_process(\n        [server.command, *server.args],\n        env=server.env if server.env is not None else get_default_environment(),\n        stderr=sys.stderr,\n )\n```\nIn particular sys.stderr here is not working in the jupyter / ipython context. Instead I would suggest a working change as follow:\n\n1. remove the stderr params from the process and handle process.stderr in an async function as stdout / stdin is handled.\n2. to that effect, use a `stderr_reader` async function  like the following:\n\n```python\n    async def stderr_reader():\n        assert process.stderr, \"Opened process is missing stderr\"\n        try:\n            async for line in process.stderr:\n                if is_jupyter_notebook():\n                    print(f\"\\033[91m {line.decode().strip()}\")\n                else:\n                    # redirect to stderr as before\n                    print(line.decode().strip(), file=sys.stderr)\n        except anyio.ClosedResourceError:\n            await anyio.lowlevel.checkpoint()\n```\n\nThis would result in the same behavior as before while allowing the stderr to be logged in the jupyter notebook context.\n\n**Additional context**\nJupyter notebook support support is also requested for mcpadapt which bring MCP server tools in any agentic framework, as many agentic framework demonstrate usage in jupyter notebooks.\nhttps://github.com/grll/mcpadapt \n","author":{"url":"https://github.com/grll","@type":"Person","name":"grll"},"datePublished":"2025-01-17T09:09:24.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/156/python-sdk/issues/156"}