How to Rebuild a Full Stack E-Commerce App from Video with Next.js & Replay in 2026

TL;DR: Learn how to reconstruct a fully functional e-commerce application from a video recording using Replay, Next.js, and Supabase, enabling rapid prototyping and code generation based on user behavior.

The future of web development isn't about meticulously crafting code from scratch. It's about leveraging AI to understand user intent and generate functional applications directly from observed behavior. Screenshot-to-code tools are relics of the past. We're moving into an era of behavior-driven reconstruction, and Replay is leading the charge.

Forget static images. We're talking about video. Think about it: a video captures the entire user experience – clicks, form submissions, page transitions, the whole flow. Replay analyzes this video data, understands the underlying user intent, and then generates production-ready code. This isn't just visual mimicry; it's intelligent reconstruction.

The Problem with Traditional Methods#

Building an e-commerce app is complex. Even with modern frameworks like Next.js, you're looking at:

• •Setting up the database schema
• •Designing UI components
• •Implementing user authentication
• •Integrating payment gateways
• •Managing state and data flow

This takes time, resources, and a deep understanding of the entire stack. What if you could bypass the majority of this manual work? That's where Replay comes in.

Behavior-Driven Reconstruction: The Replay Advantage#

Replay utilizes advanced AI, powered by Gemini, to analyze video recordings of user interactions and reconstruct functional UI. It's not just about pixels; it's about understanding what the user is trying to achieve.

Here's how Replay stacks up against traditional and even newer screenshot-to-code solutions:

Rebuilding an E-Commerce App: A Step-by-Step Guide#

Let's walk through how you can rebuild an e-commerce application from a video recording using Replay, Next.js, and Supabase.

Step 1: Capture the User Flow#

Record a video of the desired e-commerce flow. This could include:

• •Browsing products
• •Adding items to the cart
• •Proceeding to checkout
• •Entering shipping information
• •Completing the purchase

The more comprehensive the video, the better Replay can reconstruct the application.

💡 Pro Tip: Ensure clear and consistent interactions in your video recording. Avoid sudden jumps or unclear actions. Focus on showcasing the intended user flow.

Step 2: Upload to Replay#

Upload the video to Replay. Replay's AI engine will analyze the video, identify UI elements, user interactions, and application logic.

Step 3: Configure Replay Settings#

Configure the settings within Replay to match your desired stack. This includes:

• •Framework: Select Next.js
• •Database: Choose Supabase
• •Styling: Decide whether to inject styles or use CSS modules.

Step 4: Generate the Code#

Click "Generate Code." Replay will reconstruct the application based on the video analysis and your configuration.

📝 Note: The generated code includes Next.js components, API routes, Supabase database interactions, and styling.

Step 5: Review and Customize#

Review the generated code. Replay provides a clean and well-structured codebase that's easy to understand and customize.

typescript
// Example Next.js component generated by Replay
import { useState, useEffect } from 'react';
import { supabase } from '../utils/supabaseClient';

interface Product {
  id: number;
  name: string;
  price: number;
  image_url: string;
}

const ProductList = () => {
  const [products, setProducts] = useState<Product[]>([]);

  useEffect(() => {
    const fetchProducts = async () => {
      const { data, error } = await supabase
        .from('products')
        .select('*');

      if (error) {
        console.error('Error fetching products:', error);
        return;
      }

      setProducts(data || []);
    };

    fetchProducts();
  }, []);

  return (
    <div className="product-list">
      {products.map((product) => (
        <div key={product.id} className="product-item">
          <img src={product.image_url} alt={product.name} />
          <h3>{product.name}</h3>
          <p>${product.price}</p>
          <button>Add to Cart</button>
        </div>
      ))}
    </div>
  );
};

export default ProductList;

This code snippet demonstrates how Replay generates a Next.js component that fetches product data from Supabase and displays it in a list. Notice the clean structure and the use of

client for data fetching.

Step 6: Integrate with Supabase#

Replay automatically generates the necessary Supabase schema and integrates the application with your Supabase project. This includes:

• •Defining tables for products, users, orders, etc.
• •Creating API routes for data access
• •Implementing authentication logic

⚠️ Warning: Always review the generated Supabase schema and API routes to ensure they meet your security and performance requirements.

Step 7: Style Injection (Optional)#

Replay offers style injection capabilities. You can either let Replay generate CSS or inject existing styles into the generated components. This allows you to maintain a consistent design language across your application.

Step 8: Product Flow Maps#

Replay generates product flow maps, visualizing the user journey through the application. This helps you identify potential bottlenecks and optimize the user experience.

Benefits of Using Replay#

• •Speed: Generate functional code in minutes, not days.
• •Efficiency: Automate repetitive tasks and focus on high-value features.
• •Accuracy: Reconstruct applications based on real user behavior.
• •Collaboration: Share video recordings and generated code with your team.
• •Innovation: Experiment with new ideas and iterate quickly.

Replay empowers developers to build applications faster and more efficiently by leveraging the power of AI and video analysis. It's a paradigm shift in how we approach software development.

Code Example: Adding a Product to the Cart#

Here's an example of how Replay generates the code for adding a product to the cart:

typescript
// Example API route for adding a product to the cart
import { supabase } from '../../utils/supabaseClient';
import type { NextApiRequest, NextApiResponse } from 'next';

type Data = {
  message: string;
};

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse<Data>
) {
  if (req.method === 'POST') {
    const { userId, productId, quantity } = req.body;

    try {
      const { data, error } = await supabase
        .from('cart_items')
        .insert([
          { user_id: userId, product_id: productId, quantity: quantity },
        ]);

      if (error) {
        console.error('Error adding product to cart:', error);
        return res.status(500).json({ message: 'Failed to add product to cart' });
      }

      return res.status(200).json({ message: 'Product added to cart successfully' });
    } catch (error) {
      console.error('Error adding product to cart:', error);
      return res.status(500).json({ message: 'Failed to add product to cart' });
    }
  } else {
    res.status(405).json({ message: 'Method Not Allowed' });
  }
}

This API route handles the POST request to add a product to the cart. It uses the

client to insert a new record into the table.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited functionality. Paid plans provide access to advanced features, such as multi-page generation, Supabase integration, and style injection.

How is Replay different from v0.dev?#

While both Replay and v0.dev aim to accelerate UI development, Replay distinguishes itself through its use of video as the primary input. This allows Replay to understand user behavior and intent, leading to more accurate and functional code generation. V0.dev primarily uses text prompts as input.

What kind of applications can I rebuild with Replay?#

Replay is suitable for rebuilding a wide range of applications, including e-commerce apps, dashboards, landing pages, and internal tools. The key is to capture a clear and comprehensive video recording of the desired user flow.

How does Replay handle complex interactions and state management?#

Replay uses advanced AI algorithms to analyze video recordings and infer the underlying application logic. It generates code that handles complex interactions and manages state effectively.

Can I integrate Replay with my existing codebase?#

Yes, Replay generates clean and well-structured code that can be easily integrated with your existing codebase. You can also customize the generated code to meet your specific requirements.

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Ready to try behavior-driven code generation? Get started with Replay - transform any video into working code in seconds.