npm install ai @ai-sdk/openai

// app/routes/api.chat.ts
import { streamText } from 'ai';
import { openai } from '@ai-sdk/openai';
import { ActionFunctionArgs } from "@remix-run/node";

export const action = async ({ request }: ActionFunctionArgs) => {
  const { messages } = await request.json();

  const result = await streamText({
    model: openai('gpt-4-turbo'),
    messages,
  });

  return result.toDataStreamResponse();
};

// app/routes/app.assistant.tsx
import { useChat } from 'ai/react';

export default function AssistantPage() {
  const { messages, input, handleInputChange, handleSubmit } = useChat({
    api: '/api/chat', // points to the action above
  });

  return (
    <div className="chat-container">
      {messages.map(m => (
        <div key={m.id} className={m.role === 'user' ? 'user-msg' : 'ai-msg'}>
          {m.content}
        </div>
      ))}
      
      <form onSubmit={handleSubmit}>
        <input 
          value={input} 
          onChange={handleInputChange} 
          placeholder="Ask AI something..."
        />
        <button type="submit">Send</button>
      </form>
    </div>
  );
}

// app/routes/api.chat.ts
const { session } = await authenticate.admin(request);
// Fetch store data with Mongoose
const products = await Product.find({ shop: session.shop }).limit(5).lean();
const contextInfo = JSON.stringify(products);

const result = await streamText({
  model: openai('gpt-4o'),
  system: `You are a helper for shop ${session.shop}. Here are likely relevant products: ${contextInfo}`,
  messages,
});