How to rebuild a real-world e-commerce app entirely from video using Replay (2026)

TL;DR: Rebuild an entire e-commerce application from a screen recording using Replay's video-to-code engine, leveraging behavior-driven reconstruction for a functional and maintainable codebase.

The year is 2026. Screenshot-to-code tools are relics. The new frontier is understanding user intent. Imagine being able to reconstruct an entire application, not from static images, but from the behavior captured in a simple screen recording. This isn't science fiction; it's the power of Replay.

This guide will walk you through rebuilding a real-world e-commerce application using Replay, demonstrating how its video-to-code engine, powered by Gemini, can generate a functional, multi-page application with Supabase integration and style injection.

Why Video-to-Code? The Evolution of UI Reconstruction#

For years, developers have struggled with inefficient UI reconstruction methods. Screenshot-to-code tools offered a limited solution, often producing brittle and unmaintainable code. The fundamental flaw? They only see what's on the screen, not what the user is doing.

Replay changes the game. By analyzing video, Replay understands user behavior, identifies product flows, and generates code that reflects the intent behind the interactions.

Consider this comparison:

Project Overview: Rebuilding an E-commerce App#

Our goal is to rebuild a simplified e-commerce application from a screen recording. This application will feature:

• •Product listing page
• •Individual product pages with details
• •A basic shopping cart functionality
• •User authentication (leveraging Supabase)

We'll use Replay to generate the core UI components and logic, then fine-tune the application for optimal performance and user experience.

Step-by-Step Guide: Video-to-Code with Replay#

Step 1: Capture the Screen Recording#

The first step is to record a video of a user interacting with the e-commerce application you want to rebuild. Ensure the video clearly demonstrates:

• •Navigating between pages (product listings, product details, cart)
• •Adding items to the cart
• •User authentication flow (login/signup)
• •Any other key interactions or features

The clearer the video, the better Replay can understand the user's intent.

💡 Pro Tip: Narrate your actions during the recording to provide additional context for Replay. Say things like "Now I'm adding this item to the cart" or "I'm logging in with my existing account."

Step 2: Upload and Process the Video in Replay#

1. •Log in to your Replay account.
2. •Click the "Upload Video" button.
3. •Select the screen recording you captured.
4. •Replay will begin processing the video, analyzing user behavior and identifying UI elements. This process may take a few minutes depending on the video length and complexity.

Step 3: Review and Refine the Generated Code#

Once processing is complete, Replay will present you with a generated codebase. This includes:

• •React components for each page and UI element
• •TypeScript definitions for data models
• •Supabase integration for authentication and data storage
• •CSS styles for visual presentation

Review the generated code carefully. While Replay is incredibly accurate, there may be areas that require refinement or optimization.

📝 Note: Replay uses Gemini to understand the semantic meaning of UI elements, allowing it to generate more accurate and contextually relevant code.

Step 4: Implement Supabase Integration#

Replay automates much of the Supabase integration, but you'll need to configure your Supabase project.

1. •Create a Supabase project: If you don't already have one, create a new project on the Supabase platform.
2. •Configure environment variables: Set the
   text

   SUPABASE_URL
   and
   text

   SUPABASE_ANON_KEY
   environment variables in your project to connect to your Supabase database.

typescript
// .env.local
NEXT_PUBLIC_SUPABASE_URL=YOUR_SUPABASE_URL
NEXT_PUBLIC_SUPABASE_ANON_KEY=YOUR_SUPABASE_ANON_KEY

1. •Define database schema: Replay infers the database schema from the video, but you may need to adjust it based on your specific requirements. Supabase provides a user-friendly interface for managing your database schema.

sql
-- Example product table schema
CREATE TABLE products (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  name TEXT NOT NULL,
  description TEXT,
  price NUMERIC NOT NULL,
  image_url TEXT
);

Step 5: Customize Styling with Style Injection#

Replay analyzes the visual elements in the video and generates CSS styles to match the original design. You can customize these styles using CSS or your preferred styling library (e.g., Tailwind CSS, Styled Components).

1. •Locate the CSS files: Replay typically organizes CSS styles into separate files for each component.
2. •Modify the styles: Adjust the CSS rules to fine-tune the appearance of your application.

css
/* Example: Customizing the product card style */
.product-card {
  border: 1px solid #ccc;
  border-radius: 8px;
  padding: 16px;
  margin-bottom: 16px;
}

.product-card h2 {
  font-size: 1.2rem;
  margin-bottom: 8px;
}

.product-card p {
  font-size: 0.9rem;
  color: #666;
}

⚠️ Warning: Be careful when modifying the generated code. Ensure your changes don't break the application's functionality or introduce new bugs. Test your changes thoroughly.

Step 6: Implement Additional Features and Logic#

While Replay generates the core UI and basic functionality, you may need to implement additional features or logic to fully realize your e-commerce application. This could include:

• •Advanced search and filtering
• •Payment gateway integration
• •Order management
• •User reviews and ratings

Step 7: Test and Deploy#

Thoroughly test your application to ensure it functions correctly and meets your requirements. Once you're satisfied, deploy it to your preferred hosting platform (e.g., Vercel, Netlify, AWS).

Product Flow Maps: Visualizing User Journeys#

Replay generates product flow maps that visually represent the user's journey through the application. These maps provide valuable insights into how users interact with your application and can help you identify areas for improvement.

These flow maps show you:

• •The most common paths users take
• •Potential bottlenecks or drop-off points
• •Opportunities to optimize the user experience

Code Example: Generated Product Listing Component#

Here's an example of a React component generated by Replay for displaying a list of products:

typescript
// src/components/ProductList.tsx
import React, { useEffect, useState } from 'react';
import { createClient } from '@supabase/supabase-js';

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

const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL || '';
const supabaseAnonKey = process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY || '';

const supabase = createClient(supabaseUrl, supabaseAnonKey);

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

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

      if (error) {
        console.error('Error fetching products:', error);
      } else {
        setProducts(data || []);
      }
    };

    fetchProducts();
  }, []);

  return (
    <div className="product-list">
      {products.map((product) => (
        <div key={product.id} className="product-card">
          <img src={product.image_url} alt={product.name} />
          <h2>{product.name}</h2>
          <p>{product.description}</p>
          <p>${product.price}</p>
          <button>Add to Cart</button>
        </div>
      ))}
    </div>
  );
};

export default ProductList;

This component fetches product data from Supabase and renders a list of product cards. The styling is handled by the CSS classes defined in the associated CSS file.

Benefits of Using Replay#

• •Speed and Efficiency: Rebuild applications in a fraction of the time compared to traditional methods.
• •Improved Code Quality: Generate clean, maintainable code that reflects user intent.
• •Enhanced User Experience: Understand user behavior and optimize the application for optimal usability.
• •Reduced Development Costs: Automate UI reconstruction and free up developers to focus on higher-level tasks.
• •Behavior-Driven Development: Replay truly understands the user flow instead of just the visual elements.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features and usage. Paid plans are available for more advanced features and higher usage limits. Check the Replay website for the latest pricing information.

How is Replay different from v0.dev?#

While both tools aim to generate code, Replay distinguishes itself by analyzing video input and employing behavior-driven reconstruction. v0.dev primarily relies on text prompts and generates code based on specified requirements, whereas Replay observes real user interactions to create a more accurate and contextually relevant codebase. Replay understands the intent behind the UI, not just the UI itself.

What kind of applications can I rebuild with Replay?#

Replay can be used to rebuild a wide range of applications, including e-commerce apps, social media platforms, productivity tools, and more. The key is to have a clear screen recording that demonstrates the user's interactions with the application.

What if the generated code isn't perfect?#

Replay is a powerful tool, but it's not a magic bullet. The generated code may require some refinement and optimization. However, Replay significantly reduces the amount of manual coding required, saving you time and effort.

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