What You'll Build
By the end of this tutorial, you'll have a fully functional AI chatbot with:
- Real-time streaming responses (like ChatGPT)
- Conversation memory (remembers previous messages)
- Custom system prompts (define the bot's personality)
- A clean, responsive UI
- Deployed to the web for anyone to use
We'll use Next.js, Vercel AI SDK, and the Anthropic API (Claude). The same patterns work with OpenAI, Google, or any LLM provider.
Step 1: Architecture & Setup
A modern AI chatbot has three layers:
Frontend: React components that display messages, handle user input, and stream responses API Route: A serverless function that receives messages, calls the AI API, and streams the response back AI Provider: The LLM (Claude, GPT-4, etc.) that generates responses
The key architectural decision is streaming vs non-streaming. Always use streaming — it shows responses token-by-token, making the chatbot feel fast and responsive even when generating long answers.
Setup: Create a Next.js project, install the Vercel AI SDK, and add your Anthropic API key to environment variables.
Step 2: Build the API Route
The API route is simple with the Vercel AI SDK:
- 1Receive the message history from the frontend
- 2Add a system prompt that defines the bot's behavior
- 3Call the AI provider with streaming enabled
- 4Return the stream to the frontend
Key considerations: - System prompt: Define the bot's role, tone, and boundaries. Be specific: "You are a customer support agent for an e-commerce company. Only answer questions about orders, returns, and products." - Max tokens: Set reasonable limits to control costs - Temperature: Lower (0.3) for factual responses, higher (0.7) for creative ones
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Step 3: Build the UI
A great chatbot UI needs:
- Message list with clear user/assistant distinction
- Input field with send button and enter-to-submit
- Streaming display — show tokens as they arrive
- Loading state — show typing indicator while waiting
- Auto-scroll — keep the latest message visible
The Vercel AI SDK's useChat hook handles most of this automatically. It manages message state, streaming, and error handling. You just need to style the components.
Step 4: Add Memory & Advanced Features
Basic chatbots forget everything between messages. Production chatbots need:
Conversation memory: Send the full message history with each request. The AI SDK handles this, but you need to manage token limits — trim old messages when the conversation gets long.
RAG (Retrieval Augmented Generation): Connect your chatbot to a knowledge base. Use a vector database (Pinecone, Supabase) to store documents, retrieve relevant context for each query, and include it in the prompt.
Function calling: Let the chatbot take actions — look up orders, check inventory, create tickets. Define functions the AI can call, and handle the results.
Next Steps: Build More Complex AI Apps
This chatbot is just the beginning. With these same patterns, you can build:
- AI customer support agents
- Document Q&A systems
- Code review bots
- Personal AI assistants
- Multi-agent systems
CodeLeap's AI Bootcamp teaches you to build all of these — from simple chatbots to complex multi-agent systems — with live mentorship and peer collaboration.