Build an AI Chatbot in a Weekend: Step-by-Step Guide

In this tutorial, you'll build a fully functional AI chatbot with conversation memory and document context. Total time: about a weekend.

What We're Building

• A React frontend with a chat interface
• An Express backend that manages conversations
• Claude API integration for intelligent responses
• PostgreSQL for conversation history

Architecture

1React Frontend → Express API → Claude API
2                     ↓
3              PostgreSQL DB

Step 1: Project Setup

bash
1mkdir ai-chatbot && cd ai-chatbot
2npm init -y
3npm install express @anthropic-ai/sdk pg
4npm install -D typescript @types/express

Step 2: Claude Integration

typescript
1

const client = new Anthropic();

async function chat(messages: Message[]): Promise { const response = await client.messages.create({ model: 'claude-sonnet-4-20250514', max_tokens: 1024, messages: messages.map(m => ({ role: m.role, content: m.content })) }); return response.content[0].text; } ```

Step 3: Conversation History

sql
1CREATE TABLE conversations (
2  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
3  created_at TIMESTAMP DEFAULT NOW()

CREATE TABLE messages ( id UUID PRIMARY KEY DEFAULT gen_random_uuid(), conversation_id UUID REFERENCES conversations(id), role VARCHAR(10) NOT NULL, content TEXT NOT NULL, created_at TIMESTAMP DEFAULT NOW() ); ```

Step 4: Frontend

Build a clean chat UI with React — see our Projects Hub for the complete source code.

Next Steps

• Add RAG for document-grounded responses
• Implement streaming for real-time output
• Add user authentication