Building a Full-Stack AI Chat Application

In this tutorial, we will build a complete AI chat application from scratch using modern technologies.

Tech Stack

• Frontend: React, TypeScript, Tailwind CSS
• Backend: Node.js, Express, LangChain
• AI: OpenAI GPT-4, LangChain
• Database: Supabase (PostgreSQL + pgvector)

Step 1: Project Setup

Create a new project with Vite and install dependencies for both frontend and backend.

Step 2: Building the Chat UI

Create a responsive chat interface with message history, typing indicators, and markdown rendering.

Step 3: LangChain Integration

Set up LangChain with memory and streaming for a responsive chat experience.

Step 4: Adding RAG Capabilities

Integrate vector search to give your chatbot access to custom knowledge.

Step 5: Deployment

Deploy to Vercel for the frontend and Railway for the backend.

Conclusion

You now have a production-ready AI chat application. Extend it with authentication, rate limiting, and custom prompts.