# ClosedResourceError on MCP via Ngrok

**URL:** <https://community.openai.com/t/closedresourceerror-on-mcp-via-ngrok/1362417>\
**Category:** Bugs\
**Tags:** mcp\
**Created:** [October 14, 2025, 9:38am UTC](https://community.openai.com/t/closedresourceerror-on-mcp-via-ngrok/1362417 "2025-10-14T09:38:42Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Lorenzo\_Romani](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/lorenzo_romani/32/450634_2.png) [@Lorenzo\_Romani](https://community.openai.com/u/Lorenzo_Romani)\
**Post date:** [October 14, 2025, 9:38am UTC](https://community.openai.com/t/closedresourceerror-on-mcp-via-ngrok/1362417/1 "2025-10-14T09:38:42Z")

</div>

Hi!  
I have connected my MCP tools to ChatGPT Plus subscription via Developer Mode (it’s such a shame OpenAI doesn’t support custom MCP tools in the Plus Desktop app yet!). In order to make the tools available, I tunnel them via Ngrok. Everything works fine with tools that take a short time to execute; on the contrary, tools that gather a relevant amount of information (i.e.: googling a lot of stuff and retrieving snippets, titles, and urls), always fail to execute because after 1 minute or so the connection is closed and the tool is invoked again multiple times.  
This only happens when I use Ngrok to bridge my local tools to the web version of ChatGPT.  
I do not understand if this is a Ngrok issue (Ngrok paid account!) or an issue in my own MCP implementation.

ChatGPT returns this error after tool invocation:

ConnectorClientServerError: 500: “Server returned 500: ‘Request timeout’”

And the terminal shows a ClosedResourceError.

Somebody willing to help?