portfolio/docs/N8N_CHAT_SETUP.md

n8n + Ollama Chat Setup Guide

This guide explains how to set up the chat feature on your portfolio website using n8n workflows and Ollama for AI responses.

Overview

The chat system works as follows:

1. User sends a message via the chat widget on your website
2. Message is sent to your Next.js API route (/api/n8n/chat)
3. API forwards the message to your n8n webhook
4. n8n processes the message and sends it to Ollama (local LLM)
5. Ollama generates a response
6. Response is returned through n8n back to the website
7. User sees the AI response

Prerequisites

• ✅ n8n instance running (you have: https://n8n.dk0.dev)
• ✅ Ollama installed and running locally or on a server
• ✅ Environment variables configured in .env

Step 1: Set Up Ollama

Install Ollama

# macOS/Linux
curl -fsSL https://ollama.com/install.sh | sh

# Or download from https://ollama.com/download

Pull a Model

# For general chat (recommended)
ollama pull llama3.2

# Or for faster responses (smaller model)
ollama pull llama3.2:1b

# Or for better quality (larger model)
ollama pull llama3.2:70b

Run Ollama

# Start Ollama server
ollama serve

# Test it
curl http://localhost:11434/api/generate -d '{
  "model": "llama3.2",
  "prompt": "Hello, who are you?",
  "stream": false
}'

Step 2: Create n8n Workflow

2.1 Create a New Workflow in n8n

1. Go to https://n8n.dk0.dev
2. Click "Create New Workflow"
3. Name it "Portfolio Chat Bot"

2.2 Add Webhook Trigger

1. Add a Webhook node (trigger)
2. Configure:
   • HTTP Method: POST
   • Path: chat
   • Authentication: None (or add if you want)
   • Response Mode: When Last Node Finishes

Your webhook URL will be: https://n8n.dk0.dev/webhook/chat

2.3 Add Function Node (Message Processing)

Add a Function node to extract and format the message:

// Extract the message from the webhook body
const userMessage = $json.body.message || $json.message;

// Get conversation context (if you want to maintain history)
const conversationId = $json.body.conversationId || 'default';

// Create context about Dennis
const systemPrompt = `You are a helpful AI assistant on Dennis Konkol's portfolio website. 

About Dennis:
- Full-stack developer based in Osnabrück, Germany
- Student passionate about technology and self-hosting
- Skills: Next.js, React, Flutter, Docker, DevOps, TypeScript, Python
- Runs his own infrastructure with Docker Swarm and Traefik
- Projects include: Clarity (dyslexia app), self-hosted services, game servers
- Contact: contact@dk0.dev
- Website: https://dk0.dev

Be friendly, concise, and helpful. Answer questions about Dennis's skills, projects, or experience.
If asked about things unrelated to Dennis, politely redirect to his portfolio topics.`;

return {
  json: {
    userMessage,
    conversationId,
    systemPrompt,
    timestamp: new Date().toISOString()
  }
};

2.4 Add HTTP Request Node (Ollama)

Add an HTTP Request node to call Ollama:

Configuration:

• Method: POST
• URL: http://localhost:11434/api/generate (or your Ollama server URL)
• Authentication: None
• Body Content Type: JSON
• Specify Body: Using Fields Below

Body (JSON):

{
  "model": "llama3.2",
  "prompt": "{{ $json.systemPrompt }}\n\nUser: {{ $json.userMessage }}\n\nAssistant:",
  "stream": false,
  "options": {
    "temperature": 0.7,
    "top_p": 0.9,
    "max_tokens": 500
  }
}

Alternative: If Ollama is on a different server Replace localhost with your server IP/domain:

http://your-ollama-server:11434/api/generate

2.5 Add Function Node (Format Response)

Add another Function node to format the response:

// Extract the response from Ollama
const ollamaResponse = $json.response || $json.text || '';

// Clean up the response
let reply = ollamaResponse.trim();

// Remove any system prompts that might leak through
reply = reply.replace(/^(System:|Assistant:|User:)/gi, '').trim();

// Limit length if too long
if (reply.length > 1000) {
  reply = reply.substring(0, 1000) + '...';
}

return {
  json: {
    reply: reply,
    timestamp: new Date().toISOString(),
    model: 'llama3.2'
  }
};

2.6 Add Respond to Webhook Node

Add a Respond to Webhook node:

Configuration:

• Response Body: JSON
• Response Data: Using Fields Below

Body:

{
  "reply": "={{ $json.reply }}",
  "timestamp": "={{ $json.timestamp }}",
  "success": true
}

2.7 Save and Activate

1. Click "Save" (top right)
2. Toggle "Active" switch to ON
3. Test the webhook:

curl -X POST https://n8n.dk0.dev/webhook/chat \
  -H "Content-Type: application/json" \
  -d '{"message": "Hello, tell me about Dennis"}'

Step 3: Advanced - Conversation Memory

To maintain conversation context across messages, add a Redis or MongoDB node:

Option A: Using Redis (Recommended)

Add Redis Node (Store):

// Store conversation in Redis with TTL
const conversationKey = `chat:${$json.conversationId}`;
const messages = [
  { role: 'user', content: $json.userMessage },
  { role: 'assistant', content: $json.reply }
];

// Get existing conversation
const existing = await this.helpers.request({
  method: 'GET',
  url: `redis://localhost:6379/${conversationKey}`
});

// Append new messages
const conversation = existing ? JSON.parse(existing) : [];
conversation.push(...messages);

// Keep only last 10 messages
const recentConversation = conversation.slice(-10);

// Store back with 1 hour TTL
await this.helpers.request({
  method: 'SET',
  url: `redis://localhost:6379/${conversationKey}`,
  body: JSON.stringify(recentConversation),
  qs: { EX: 3600 }
});

Option B: Using Session Storage (Simpler)

Store conversation in n8n's internal storage:

// Use n8n's static data for simple storage
const conversationKey = $json.conversationId;
const staticData = this.getWorkflowStaticData('global');

if (!staticData.conversations) {
  staticData.conversations = {};
}

if (!staticData.conversations[conversationKey]) {
  staticData.conversations[conversationKey] = [];
}

// Add message
staticData.conversations[conversationKey].push({
  user: $json.userMessage,
  assistant: $json.reply,
  timestamp: new Date().toISOString()
});

// Keep only last 10
staticData.conversations[conversationKey] = 
  staticData.conversations[conversationKey].slice(-10);

Step 4: Handle Multiple Users

The chat system automatically handles multiple users through:

1. Session IDs: Each user gets a unique conversationId generated client-side
2. Stateless by default: Each request is independent unless you add conversation memory
3. Redis/Database: Store conversations per user ID for persistent history

Client-Side Session Management

The chat widget (created in next step) will generate a unique session ID:

// Auto-generated in the chat widget
const conversationId = crypto.randomUUID();
localStorage.setItem('chatSessionId', conversationId);

Server-Side (n8n)

n8n processes each request independently. For multiple concurrent users:

• Each webhook call is a separate execution
• No shared state between users (unless you add it)
• Ollama can handle concurrent requests
• Use Redis for scalable conversation storage

Step 5: Rate Limiting (Optional)

To prevent abuse, add rate limiting in n8n:

// Add this as first function node
const ip = $json.headers['x-forwarded-for'] || $json.headers['x-real-ip'] || 'unknown';
const rateLimitKey = `ratelimit:${ip}`;
const staticData = this.getWorkflowStaticData('global');

if (!staticData.rateLimits) {
  staticData.rateLimits = {};
}

const now = Date.now();
const limit = staticData.rateLimits[rateLimitKey] || { count: 0, resetAt: now + 60000 };

if (now > limit.resetAt) {
  // Reset after 1 minute
  limit.count = 0;
  limit.resetAt = now + 60000;
}

if (limit.count >= 10) {
  // Max 10 requests per minute per IP
  throw new Error('Rate limit exceeded. Please wait a moment.');
}

limit.count++;
staticData.rateLimits[rateLimitKey] = limit;

Step 6: Environment Variables

Update your .env file:

# n8n Configuration
N8N_WEBHOOK_URL=https://n8n.dk0.dev
N8N_SECRET_TOKEN=your-secret-token-here  # Optional: for authentication
N8N_API_KEY=your-api-key-here            # Optional: for API access

# Ollama Configuration (optional - stored in n8n workflow)
OLLAMA_URL=http://localhost:11434
OLLAMA_MODEL=llama3.2

Step 7: Test the Setup

# Test the chat endpoint
curl -X POST http://localhost:3000/api/n8n/chat \
  -H "Content-Type: application/json" \
  -d '{
    "message": "What technologies does Dennis work with?"
  }'

# Expected response:
{
  "reply": "Dennis works with a variety of modern technologies including Next.js, React, Flutter for mobile development, Docker for containerization, and TypeScript. He's also experienced with DevOps practices, running his own infrastructure with Docker Swarm and Traefik as a reverse proxy."
}

Troubleshooting

Ollama Not Responding

# Check if Ollama is running
curl http://localhost:11434/api/tags

# If not, start it
ollama serve

# Check logs
journalctl -u ollama -f

n8n Webhook Returns 404

• Make sure workflow is Active (toggle in top right)
• Check webhook path matches: /webhook/chat
• Test directly: https://n8n.dk0.dev/webhook/chat

Slow Responses

• Use a smaller model: ollama pull llama3.2:1b
• Reduce max_tokens in Ollama request
• Add response caching for common questions
• Consider using streaming responses

CORS Issues

Add CORS headers in the n8n Respond node:

{
  "headers": {
    "Access-Control-Allow-Origin": "*",
    "Access-Control-Allow-Methods": "POST, OPTIONS",
    "Access-Control-Allow-Headers": "Content-Type"
  }
}

Performance Tips

1. Use GPU acceleration for Ollama if available
2. Cache common responses in Redis
3. Implement streaming for real-time responses
4. Use smaller models for faster responses (llama3.2:1b)
5. Add typing indicators in the UI while waiting

Security Considerations

1. Add authentication to n8n webhook (Bearer token)
2. Implement rate limiting (shown above)
3. Sanitize user input in n8n function node
4. Don't expose Ollama directly to the internet
5. Use HTTPS for all communications
6. Add CAPTCHA to prevent bot abuse

Next Steps

1. ✅ Set up Ollama
2. ✅ Create n8n workflow
3. ✅ Test the API endpoint
4. 🔲 Create chat UI widget (see CHAT_WIDGET_SETUP.md)
5. 🔲 Add conversation memory
6. 🔲 Implement rate limiting
7. 🔲 Add analytics tracking

Resources

• Ollama Documentation
• n8n Documentation
• Llama 3.2 Model Card
• Next.js API Routes

Example n8n Workflow JSON

Save this as chat-workflow.json and import into n8n:

{
  "name": "Portfolio Chat Bot",
  "nodes": [
    {
      "parameters": {
        "path": "chat",
        "responseMode": "lastNode",
        "options": {}
      },
      "name": "Webhook",
      "type": "n8n-nodes-base.webhook",
      "position": [250, 300],
      "webhookId": "chat-webhook"
    },
    {
      "parameters": {
        "functionCode": "const userMessage = $json.body.message;\nconst systemPrompt = `You are a helpful AI assistant on Dennis Konkol's portfolio website.`;\nreturn { json: { userMessage, systemPrompt } };"
      },
      "name": "Process Message",
      "type": "n8n-nodes-base.function",
      "position": [450, 300]
    },
    {
      "parameters": {
        "method": "POST",
        "url": "http://localhost:11434/api/generate",
        "jsonParameters": true,
        "options": {},
        "bodyParametersJson": "={ \"model\": \"llama3.2\", \"prompt\": \"{{ $json.systemPrompt }}\\n\\nUser: {{ $json.userMessage }}\\n\\nAssistant:\", \"stream\": false }"
      },
      "name": "Call Ollama",
      "type": "n8n-nodes-base.httpRequest",
      "position": [650, 300]
    },
    {
      "parameters": {
        "functionCode": "const reply = $json.response || '';\nreturn { json: { reply: reply.trim() } };"
      },
      "name": "Format Response",
      "type": "n8n-nodes-base.function",
      "position": [850, 300]
    },
    {
      "parameters": {
        "respondWith": "json",
        "options": {},
        "responseBody": "={ \"reply\": \"{{ $json.reply }}\", \"success\": true }"
      },
      "name": "Respond to Webhook",
      "type": "n8n-nodes-base.respondToWebhook",
      "position": [1050, 300]
    }
  ],
  "connections": {
    "Webhook": { "main": [[{ "node": "Process Message", "type": "main", "index": 0 }]] },
    "Process Message": { "main": [[{ "node": "Call Ollama", "type": "main", "index": 0 }]] },
    "Call Ollama": { "main": [[{ "node": "Format Response", "type": "main", "index": 0 }]] },
    "Format Response": { "main": [[{ "node": "Respond to Webhook", "type": "main", "index": 0 }]] }
  }
}

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Need help? Check the troubleshooting section or reach out!