n8n MCP Server

# Troubleshooting Guide This guide addresses common issues you might encounter when setting up and using the n8n MCP Server. ## Connection Issues ### Cannot Connect to n8n API **Symptoms:** - Error messages mentioning "Connection refused" or "Cannot connect to n8n API" - Timeout errors when trying to use MCP tools **Possible Solutions:** 1. **Verify n8n is running:** - Ensure your n8n instance is running and accessible - Try accessing the n8n URL in a browser 2. **Check n8n API URL:** - Verify the `N8N_API_URL` in your `.env` file - Make sure it includes the full path (e.g., `http://localhost:5678/api/v1`) - Check for typos or incorrect protocol (http vs https) 3. **Network Configuration:** - If running on a different machine, ensure there are no firewall rules blocking access - Check if n8n is configured to allow remote connections 4. **HTTPS/SSL Issues:** - If using HTTPS, ensure certificates are valid - For self-signed certificates, you may need to set up additional configuration ### Authentication Failures **Symptoms:** - "Authentication failed" or "Invalid API key" messages - 401 or 403 HTTP status codes **Possible Solutions:** 1. **Verify API Key:** - Check that the `N8N_API_KEY` in your `.env` file matches the one in n8n - Create a new API key if necessary 2. **Check API Key Permissions:** - Ensure the API key has appropriate scopes/permissions - Required scopes: `workflow:read workflow:write workflow:execute` 3. **n8n API Settings:** - Verify that API access is enabled in n8n settings - Check if there are IP restrictions on API access ## MCP Server Issues ### Server Crashes or Exits Unexpectedly **Symptoms:** - The MCP server stops running unexpectedly - Error messages in logs or console output **Possible Solutions:** 1. **Check Node.js Version:** - Ensure you're using Node.js 20 or later - Check with `node --version` 2. **Check Environment Variables:** - Ensure all required environment variables are set - Verify the format of the environment variables 3. **View Debug Logs:** - Set `DEBUG=true` in your `.env` file - Check the console output for detailed error messages 4. **Memory Issues:** - If running on a system with limited memory, increase available memory - Check for memory leaks or high consumption patterns ### AI Assistant Cannot Communicate with MCP Server **Symptoms:** - AI assistant reports it cannot connect to the MCP server - Tools are not available in the assistant interface **Possible Solutions:** 1. **Verify Server Registration:** - Ensure the server is properly registered with your AI assistant platform - Check the configuration settings for the MCP server in your assistant 2. **Server Running Check:** - Verify the MCP server is running - Check that it was started with the correct environment 3. **Restart Components:** - Restart the MCP server - Refresh the AI assistant interface - If using a managed AI assistant, check platform status ## Tool-Specific Issues ### Workflow Operations Fail **Symptoms:** - Cannot list, create, or update workflows - Error messages about missing permissions **Possible Solutions:** 1. **API Key Scope:** - Ensure your API key has `workflow:read` and `workflow:write` permissions - Create a new key with appropriate permissions if needed 2. **n8n Version:** - Check if your n8n version supports all the API endpoints being used - Update n8n to the latest version if possible 3. **Workflow Complexity:** - Complex workflows with custom nodes may not work correctly - Try with simpler workflows to isolate the issue ### Execution Operations Fail **Symptoms:** - Cannot execute workflows or retrieve execution data - Execution starts but fails to complete **Possible Solutions:** 1. **API Key Scope:** - Ensure your API key has the `workflow:execute` permission - Create a new key with appropriate permissions if needed 2. **Workflow Status:** - Check if the target workflow is active - Verify the workflow executes correctly in the n8n interface 3. **Workflow Inputs:** - Ensure all required inputs for workflow execution are provided - Check the format of input data ## Getting More Help If you're still experiencing issues after trying these troubleshooting steps: 1. **Check GitHub Issues:** - Look for similar issues in the [GitHub repository](https://github.com/yourusername/n8n-mcp-server/issues) - Create a new issue with detailed information about your problem 2. **Submit Logs:** - Enable debug logging with `DEBUG=true` - Include relevant logs when seeking help 3. **Community Support:** - Ask in the n8n community forums - Check MCP-related discussion groups