Issues Setting Up n8n-MCP with Claude Desktop (Full Error Breakdown and Observations)

[ken4ward]

I’ve been trying to set up n8n-MCP with Claude Desktop, but the integration process has been far from smooth. I’m documenting everything here so others who have faced similar problems can reference or contribute fixes.

Setup Environment

• macOS (arm64)
• Claude Desktop v0.14.10
• Node v22.19.0
• n8n-mcp installed globally via npm

Primary Objective
Connect n8n-MCP as an MCP server so Claude can trigger or read n8n workflows locally via HTTP or an ngrok tunnel.

Claude log messages showing partial connection

I followed the simple installation procedure, but to my surprise, it did not yield the desired result: it did not connect to Claude Dektop. This is the setup used in Claude config

{
  "mcpServers": {
    "n8n-mcp": {
      "command": "npx",
      "args": ["n8n-mcp"],
      "env": {
        "MCP_MODE": "stdio",
        "LOG_LEVEL": "error",
        "DISABLE_CONSOLE_OUTPUT": "true",
        "N8N_API_URL": "https://n8n-installation-domain.n8n",
        "N8N_API_KEY": "n8nAPIKey"
      }
    }
  }
}

An expert should kindly help look into this. God bless.

This is the error it returned

Could not attch to MCP server: n8n-mcp
MCP n8n-mcp: Server disconnected. For troubleshooting guidance, please visit our

[cypher-testeur-ia]

got the same issue, did you find any fix?

[cypher-testeur-ia]

I found the solution :

Replace :
"command": "npx",
"args": ["n8n-mcp"],

With :
"command": "/Users/yourname/.nvm/versions/node/v20.17.0/bin/node",
"args":
["/Users/yourname/n8n-mcp/dist/mcp/index.js"],

The issue was that npx was closing stdin immediately, which triggered the server shutdown. By using node directly, stdin stays properly connected for MCP communication.

[cmj-hub]

✅ Fixed in commit [latest]

Solution:

• Added warning about npx connection issues
• Added Option B using direct node path (recommended)
• Documented why direct node path fixes the issue
• Added instructions for finding node and n8n-mcp paths
• Updated both basic and full configuration examples

Files Changed:

• README.md

Root Cause:
npx closes stdin immediately on some systems, causing "Server disconnected" errors. Using the direct node path ensures stdin stays properly connected for MCP communication.

Solution:
Use the direct node path instead of npx:

{
  "mcpServers": {
    "n8n-mcp": {
      "command": "/Users/yourname/.nvm/versions/node/v20.17.0/bin/node",
      "args": ["/Users/yourname/n8n-mcp/node_modules/n8n-mcp/dist/mcp/index.js"],
      "env": {
        "MCP_MODE": "stdio",
        "LOG_LEVEL": "error",
        "DISABLE_CONSOLE_OUTPUT": "true"
      }
    }
  }
}

Finding your paths:

• Node path: which node (macOS/Linux) or where node (Windows)
• n8n-mcp path: npm list -g n8n-mcp (if installed globally) or find in node_modules/n8n-mcp/dist/mcp/index.js

Testing:
All tests pass ✅

[Ewoodster]

Since I've been struggeling to get it up and running for hours, here is the path I found on MacOs that works for me.
May it help others:

{
  "mcpServers": {
    "n8n-mcp": {
      "command": "/opt/homebrew/bin/node",
      "args": ["/opt/homebrew/lib/node_modules/n8n-mcp/dist/mcp/index.js"],
      "env": {
        "MCP_MODE": "stdio",
        "LOG_LEVEL": "error",
        "DISABLE_CONSOLE_OUTPUT": "true",
        "N8N_API_URL": "myURL(insert  your own n8n URL)",
        "N8N_API_KEY": "(insert your own very long API key here"
      }
    }
  }
}