I’m using the langchain_mcp_adapters library to integrate MCP (Model Context Protocol) filesystem tools with LangChain on Windows. The initial connection succeeds and lists tools correctly, but fails with a Connection closed error when attempting to call any tool. from langchain.chat_models import …

Hi @lreal have you tries response = await model_with_tools.ainvoke(messages)?

Hi Guys, am facing similar error. Could someone tell me any solution for this ?

hi @ScarletMercy , can you please see the below attached issue and give your inputs on what can be done to resolve the issue. Thanks! Failing at get_tools() in production environment

same error ,cat not work with google’s chrome-devtools mcp which use npx async def initialize_tools(): chrome_devtools = MultiServerMCPClient( { "chrome-devtools": { "command": "npx", "args": ["-y", "chrome-devtools-mcp@latest"], …

LangChain MCP Adapter throws "Connection closed" error when calling tools on Windows with npx stdio transport

OSS Product Help LangChain

ScarletMercy November 24, 2025, 7:21am 6

You only need to create a Stateful tool session. For details, please refer to https://docs.langchain.com/oss/python/langchain/mcp#stateful-tool-usage.

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LangChain MCP Adapter throws "Connection closed" error when calling tools on Windows with npx stdio transport

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