Comprehensive solutions for common issues when connecting AI assistants to n8n workflows.

Before diving into specific issues, try these diagnostic commands with your AI assistant:

"Test my n8n connection"
"Show me the server status"
"List my workflows" (basic connectivity test)
"What's my n8n instance information?"

Symptoms:

• Cannot connect to n8n instance
• Timeout errors when trying to list workflows
• "Network unreachable" messages

Solutions:

1. Verify n8n Instance is Running

   # Check if n8n is accessible
   curl -I https://your-n8n-instance.com

2. Check N8N_HOST Configuration

   • ✅ Correct: https://your-n8n.com
   • ✅ Correct: http://localhost:5678
   • ❌ Wrong: your-n8n.com (missing protocol)
   • ❌ Wrong: https://your-n8n.com/ (trailing slash)

3. Network Connectivity

   • Test from browser: Visit your n8n instance URL
   • Check firewall settings
   • Verify VPN/proxy configuration

4. Port Configuration

   • Default n8n port: 5678
   • n8n Cloud: Use full HTTPS URL
   • Self-hosted: Include custom port if different

AI Assistant Command to Test:

"Check if my n8n instance at [your-url] is accessible"

Symptoms:

• "Invalid API key" messages
• "Unauthorized access" errors
• Can connect but cannot perform actions

Solutions:

1. Verify API Key Format

   • ✅ Correct: n8n_api_1234567890abcdef...
   • ❌ Wrong: Missing n8n_api_ prefix
   • ❌ Wrong: Truncated or incomplete key

2. Check API Key Permissions

   • Ensure key has workflow management permissions
   • Verify key hasn't expired
   • Test key with direct API call:

   curl -H "X-N8N-API-KEY: your-api-key" https://your-n8n.com/api/v1/workflows

3. Regenerate API Key

   • Go to n8n Settings → API Keys
   • Delete old key and create new one
   • Update MCP server configuration

AI Assistant Command to Test:

"Verify my n8n API key permissions"

Symptoms:

• Specific workflows cannot be accessed
• "Workflow ID does not exist" messages
• Some workflows visible, others not

Solutions:

1. List All Workflows First

   "List all my n8n workflows with their IDs"
   

2. Check Workflow ID Format

   • Use exact ID from workflow list
   • IDs are typically numeric or UUID format
   • Case-sensitive in some configurations

3. Verify Workflow Permissions

   • Ensure API key has access to specific workflows
   • Check if workflow is in different project/workspace

Symptoms:

• MCP server fails to launch
• "Cannot find module" errors
• "Command not found" messages

Solutions:

1. Check Node.js Version

   node --version  # Must be 18.0.0 or higher

2. Clear npm Cache

   npm cache clean --force

3. Reinstall Package

   npm uninstall -g @makafeli/n8n-workflow-builder
   npm install -g @makafeli/n8n-workflow-builder

4. Use NPX Instead

   npx @makafeli/n8n-workflow-builder

Symptoms:

• Cannot install package globally
• "EACCES" permission errors
• Installation fails with permission issues

Solutions:

1. Use NPX (Recommended)

   npx @makafeli/n8n-workflow-builder

2. Fix npm Permissions

   # Configure npm to use different directory
   mkdir ~/.npm-global
   npm config set prefix '~/.npm-global'
   echo 'export PATH=~/.npm-global/bin:$PATH' >> ~/.bashrc
   source ~/.bashrc

3. Use Node Version Manager

   # Install nvm and use it to manage Node.js
   curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.0/install.sh | bash
   nvm install 18
   nvm use 18

Symptoms:

• MCP server not appearing in Claude Desktop
• "Server failed to start" in Claude
• Configuration not loading

Solutions:

1. Check Configuration File Location

   • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
   • Windows: %APPDATA%\Claude\claude_desktop_config.json

2. Validate JSON Syntax

   {
     "mcpServers": {
       "n8n-workflow-builder": {
         "command": "npx",
         "args": ["@makafeli/n8n-workflow-builder"],
         "env": {
           "N8N_HOST": "https://your-n8n-instance.com",
           "N8N_API_KEY": "your-api-key-here"
         }
       }
     }
   }

3. Restart Claude Desktop

   • Completely quit Claude Desktop
   • Wait 10 seconds
   • Restart application

4. Check Environment Variables

   • Ensure no quotes around environment values
   • Verify special characters are properly escaped
   • Test with minimal configuration first

Symptoms:

• MCP server not recognized in Cline
• "Failed to connect to MCP server" errors
• Tools not appearing in Cline interface

Solutions:

1. Update Cline Extension

   • Ensure latest version of Cline is installed
   • Check VS Code extension updates

2. Verify MCP Configuration

   • Check Cline settings for MCP server configuration
   • Ensure configuration matches expected format

3. Restart VS Code

   • Reload VS Code window
   • Restart VS Code completely if needed

Symptoms:

• AI cannot create new workflows
• "Invalid workflow configuration" errors
• Workflows created but not functional

Solutions:

1. Simplify Workflow Request

   "Create a simple webhook workflow with just a trigger and HTTP response"
   

2. Check Node Availability

   • Verify required nodes are installed in n8n
   • Update n8n to latest version for node compatibility

3. Validate Workflow Structure

   • Ensure proper node connections
   • Check required parameters are provided

Symptoms:

• Workflows created but fail to execute
• "Node execution error" messages
• Partial workflow execution

Solutions:

1. Check Node Configuration

   "Show me the configuration of my [workflow-name] workflow"
   

2. Test Individual Nodes

   • Execute workflow step by step
   • Identify failing node

3. Review Error Logs

   "Show me the execution logs for workflow [workflow-id]"
   

For Detailed Logging:

DEBUG=n8n-workflow-builder npx @makafeli/n8n-workflow-builder

For Network Debugging:

DEBUG=axios npx @makafeli/n8n-workflow-builder

For Full Debug Output:

DEBUG=* npx @makafeli/n8n-workflow-builder

Connection Issues:

DEBUG: Attempting connection to https://your-n8n.com
DEBUG: Request headers: { 'X-N8N-API-KEY': 'n8n_api_...' }
ERROR: ECONNREFUSED - Connection refused

Authentication Issues:

DEBUG: API request to /api/v1/workflows
DEBUG: Response status: 401
ERROR: Unauthorized - Invalid API key

Before seeking help, verify:

• ✅ Node.js version 18.0.0 or higher
• ✅ n8n instance is accessible via browser
• ✅ API key is valid and has proper permissions
• ✅ MCP server configuration is correct
• ✅ AI assistant is properly configured

"Run a full diagnostic of my n8n MCP setup"
"Test all my n8n workflow tools"
"Show me my current n8n configuration"
"Verify my API key permissions"

1. GitHub Issues: Report bugs and get help
2. n8n Community: General n8n support
3. MCP Documentation: Model Context Protocol docs
4. Claude Desktop Support: Anthropic support

When reporting issues, include:

1. Environment Information

   • Operating system and version
   • Node.js version
   • n8n version and hosting type (cloud/self-hosted)
   • AI assistant type and version

2. Configuration Details

   • MCP server configuration (remove sensitive data)
   • Environment variables (remove API keys)
   • Debug logs (if available)

3. Steps to Reproduce

   • Exact commands or requests made
   • Expected vs actual behavior
   • Error messages (full text)

4. Diagnostic Output

   # Include output from these commands
   node --version
   npm list -g @makafeli/n8n-workflow-builder
   DEBUG=n8n-workflow-builder npx @makafeli/n8n-workflow-builder

1. Regular Updates

   • Keep n8n instance updated
   • Update MCP server package regularly
   • Update AI assistant applications

2. Configuration Management

   • Use environment files for credentials
   • Document your configuration
   • Test configuration changes in development first

3. Monitoring

   • Set up basic monitoring for n8n instance
   • Monitor API key usage and permissions
   • Track workflow execution success rates

4. Backup and Recovery

   • Export important workflows regularly
   • Document custom configurations
   • Keep API key backup in secure location

Still having issues? Ask your AI assistant: "Help me troubleshoot my n8n MCP server connection" 🔧