Unable to attach MCP Server on windows 11

[usama-dtc]

What happened?

I tried to attach MCP server with LibreChat on windows 11

librechat.yaml:

mcpServers:
  puppeteer:
    command: npx
    args:
      - -y
      - "@modelcontextprotocol/server-puppeteer"

In the logs I see this:

LibreChat         | 2025-04-16 21:26:29 info: [MCP] Initializing app-level servers
LibreChat         | 2025-04-16 21:26:39 error: [MCP][puppeteer] Connection failed: Connection timeout
LibreChat         | 2025-04-16 21:26:41 error: [MCP][puppeteer] Connection failed: MCP error -32000: Connection closed
LibreChat         | 2025-04-16 21:26:55 error: [MCP][puppeteer] Connection failed: Connection timeout
LibreChat         | 2025-04-16 21:26:55 error: [MCP][puppeteer] Failed to connect after 3 attempts Connection timeout
LibreChat         | 2025-04-16 21:26:55 error: [MCP][puppeteer] Initialization failed Connection timeout
LibreChat         | 2025-04-16 21:26:55 info: [MCP] Initialized 0/1 app-level server(s)
LibreChat         | 2025-04-16 21:26:55 warn: [MCP] 1/1 app-level server(s) failed to initialize
LibreChat         | 2025-04-16 21:26:55 info: [MCP][puppeteer] ✗ Failed
LibreChat         | 2025-04-16 21:26:55 warn: [MCP] No app-level servers initialized

Docker-Compose:

services:
  api:
    volumes:
      - ./librechat.yaml:/app/librechat.yaml

I have followed the installation instrcutions mentioned in LibreChat Docs

Version Information

ghcr.io/danny-avila/librechat-dev latest 9271978cdfd6 38 hours ago 1.6GB
ghcr.io/danny-avila/librechat-rag-api-dev-lite latest 566585698235 8 days ago 1.85GB

Steps to Reproduce

docker compose up

What browsers are you seeing the problem on?

No response

Relevant log output

Screenshots

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[goalkeepr]

For what it's worth, same issue here on Ubuntu.

[spammenotinoz]

Same issue on Ubuntu, config was cut and pasted from the docs. Even tried a global install, so the package exists.
2025-05-21 11:50:57 info: [MCP] Initializing app-level servers
2025-05-21 11:51:07 error: [MCP][puppeteer] Connection failed: Connection timeout
2025-05-21 11:51:09 error: [MCP][puppeteer] Connection failed: MCP error -32000: Connection closed

mcpServers:
puppeteer:
type: stdio
command: npx
args:
- -y
- "@modelcontextprotocol/server-puppeteer"
timeout: 30000
initTimeout: 10000
env:
NODE_ENV: "production"
stderr: inherit

[danny-avila]

On the latest version of LibreChat, I'm not having any issues with this MCP server ("@modelcontextprotocol/server-puppeteer") using Windows.

2025-05-21T12:22:16.826Z info: [MCP] Initialized 1/1 app-level server(s)
2025-05-21T12:22:16.826Z info: [MCP][puppeteer] ✓ Initialized
2025-05-21T12:22:16.827Z info: [MCP] All app-level servers initialized successfully
2025-05-21T12:22:16.827Z debug: [MCP][puppeteer] Transport sending: {"method":"ping","jsonrpc":"2.0","id":5}
2025-05-21T12:22:16.827Z debug: [MCP][puppeteer] Transport sending: {"method":"tools/list","jsonrpc":"2.0","id":6}

mcpServers:
  puppeteer:
    type: stdio
    command: npx
    args:
      - -y
      - "@modelcontextprotocol/server-puppeteer"

Previously, on Windows, you may have needed to point to your exact npm installation for npx to work properly but this was resolved in the MCP SDK.

The other issues are concerning docker, which this MCP server doesn't properly support:

modelcontextprotocol/servers#749

[spammenotinoz]

Thankyou

[goalkeepr]

I am using docker. This might be the issue.

…

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