Chatbot Architecture
How modern AI chatbots are built - from simple Q&A bots to fully autonomous agents that take actions on behalf of users.
Three Types of AI Chatbots
Not all chatbots are created equal. Understanding these three architectures helps you choose the right approach for your needs.
Basic LLM Chatbot
Direct conversation with an LLM. Simple to set up but limited to the model's training data.
RAG Chatbot
PopularLLM enhanced with your documents. Answers based on your actual content.
Agent Chatbot
Full autonomy with function calling. Can retrieve data AND take actions.
| Feature | Basic LLM | RAG Chatbot | Agent Chatbot |
|---|---|---|---|
Knowledge source Where the bot gets information | LLM training data only | Your documents + LLM | Documents + External systems |
Accuracy on your data Answers about your specific business | Low - often wrong | High - from your docs | High - plus real-time data |
Can take actions Book, update, create, etc. | |||
Setup complexity Time and effort to implement | Low | Medium | High |
Best for Ideal use cases | General Q&A | Knowledge bases | Full automation |
The Conversation Processing Loop
Every message flows through this pipeline. Understanding each step helps you optimize performance and debug issues.
Chatbot Architecture | How It Works
User sends a message via any channel
Details
The system receives a message from WhatsApp, web chat, SMS, or any connected channel. Messages are normalized into a standard format regardless of source.
Example
2. Context Loading
Retrieve conversation history and user data
Details
The system loads previous messages from the current session, the user's profile data, and any relevant metadata. This context helps the LLM understand the full situation.
Example
3. RAG Retrieval
Search knowledge base for relevant info
Details
If RAG is enabled, the user's message is embedded and used to search the vector database for relevant documents. The top matches are retrieved to provide context for the response.
Example
4. LLM Processing
Generate response with all context
Details
The LLM receives: system prompt, conversation history, RAG context, user profile, and the current message. It generates a response and may trigger function calls.
Example
5. Action Execution
Run function calls and get results
Details
If the LLM requested function calls, they're executed against your backend systems. Results are fed back to the LLM to incorporate into the response.
Example
6. Response & Storage
Send response and save to memory
Details
The final response is sent back to the user via their original channel. The conversation is saved to memory for future context.
Example
Total Processing Time: ~700ms
A well-optimized chatbot can process messages in under a second. The LLM step is typically the slowest, but streaming responses make the experience feel faster.
Multi-Channel Architecture
Modern chatbots meet customers where they are. A unified architecture handles WhatsApp, web chat, SMS, and more through a single brain.
Rich media, quick replies
Web Widget
Embedded on your site
SMS
Universal reach
Messenger
Facebook integration
Unified conversation history
Start on WhatsApp, continue on web - context preserved
Single knowledge base
Update once, deploy everywhere
Channel-specific features
Rich media on WhatsApp, buttons on web
Channel Configuration Example
1{2 "channels": {3 "whatsapp": {4 "enabled": true,5 "provider": "twilio",6 "features": ["rich_media", "quick_replies", "location"]7 },8 "web_widget": {9 "enabled": true,10 "customization": {11 "primary_color": "#1a73e8",12 "position": "bottom-right"13 }14 },15 "sms": {16 "enabled": true,17 "provider": "twilio",18 "features": ["text_only"]19 },20 "facebook_messenger": {21 "enabled": true,22 "features": ["rich_media", "quick_replies", "persistent_menu"]23 }24 },25 "unified_inbox": true,26 "conversation_continuity": true27}Human Handoff: When AI Steps Aside
The best chatbots know their limits. Seamless handoff to human agents ensures complex issues get proper attention.
The AI recognizes triggers indicating a human should take over:
- • User explicitly requests human ("talk to a person")
- • Sentiment analysis detects frustration
- • Complex issue outside AI's scope
- • Multiple failed resolution attempts
AI generates a summary for the human agent:
Handoff Summary:
Customer frustrated about delayed order #12345. Shipping shows "in transit" for 5 days. Wants refund or express reshipping. High-value customer (3 previous orders).
Available agent receives notification with full context.
Customer is smoothly connected to agent:
"I'm connecting you with Sarah from our support team. She has your order details and will help resolve this right away."
Automatic Escalation Triggers
- • User explicitly requests human
- • Negative sentiment detected (3+ messages)
- • Issue marked as "high complexity"
- • Failed to resolve after 3 attempts
- • VIP customer flag
- • Legal/compliance keywords detected
Handoff Best Practices
- • Generate conversation summary
- • Include customer sentiment score
- • Pass user profile and history
- • Skill-based agent routing
- • Clear transition message to user
- • Allow agent to see full transcript
Security Considerations
Chatbots handle sensitive customer data. A secure architecture protects both your users and your business.
PII Protection
Automatically detect and redact credit card numbers, SSNs, and other sensitive data before it reaches the LLM. Never store raw PII in conversation logs.
Prompt Injection Defense
Users may try to manipulate the chatbot with crafted prompts. Implement input sanitization, output validation, and system prompt protection layers.
Data Handling
Encrypt all data in transit (TLS) and at rest. Implement data retention policies. Provide data export and deletion for GDPR compliance.
Security Features Comparison
| Feature | Enterprise | Standard | Basic |
|---|---|---|---|
PII redaction Automatically mask sensitive data | |||
Prompt injection protection Block manipulation attempts | |||
Data encryption (at rest) Encrypted storage | |||
Data encryption (in transit) TLS/SSL connections | |||
Audit logging Complete conversation logs | |||
Role-based access Control who sees what |
Enterprise solutions include comprehensive security features. For compliance-heavy industries, these are non-negotiable.
Complete Architecture Overview
How all the pieces fit together in a production chatbot system.
Channels
Core System
Integrations
← Messages flow bidirectionally between all components →
Ready to Build Your Chatbot?
We architect and build production-ready chatbots that scale. From simple RAG assistants to full agent systems with deep integrations.
Related Resources
RAG Chatbots
Production RAG chatbots built on the architecture patterns discussed in this guide.
Learn moreWhat is an AI Chatbot?
Beginner-friendly introduction to AI chatbots before diving into architecture details.
Learn moreRAG Explained
Deep dive into retrieval-augmented generation — the key architecture component for accurate AI.
Learn moreSecurity Automation
Secure your chatbot architecture with automated threat detection and compliance monitoring.
Learn more