Replay AI for Building Custom Applications from Design Systems: Step-by-Step

TL;DR: Replay AI reconstructs functional UIs from video recordings, enabling rapid application development that adheres to design system principles.

Building custom applications that perfectly mirror your design system can be a tedious and error-prone process. Traditional methods often involve manually translating design specs into code, leading to inconsistencies and delays. But what if you could simply record a user flow and have a working application generated for you, complete with design system adherence? That's the power of Replay.

Replay: Bridging the Gap Between Design and Code#

Replay utilizes Behavior-Driven Reconstruction, analyzing video recordings of user interactions to generate functional UI code. Unlike screenshot-to-code tools that merely capture visual elements, Replay understands the intent behind each action, resulting in a more accurate and robust code generation process. This approach is particularly beneficial when building applications based on established design systems.

Here's how Replay stands apart from other tools:

Step-by-Step Guide: Building a Custom Application with Replay and Your Design System#

This guide walks you through the process of using Replay to build a custom application that seamlessly integrates with your existing design system.

Step 1: Prepare Your Design System#

Ensure your design system is well-documented and accessible. Ideally, it should include:

• •Component Library: A collection of reusable UI components (e.g., buttons, inputs, cards).
• •Style Guide: Defines the visual language of your application (e.g., colors, typography, spacing).
• •Coding Conventions: Establishes best practices for code structure and maintainability.

Replay can leverage this information to generate code that aligns with your design system's principles.

Step 2: Record Your User Flow#

Using a screen recording tool (e.g., OBS Studio, QuickTime), record a video of yourself interacting with a prototype or existing application that embodies your desired user flow. Be sure to:

• •Clearly demonstrate each interaction: Highlight buttons, fill out forms, and navigate between pages.
• •Speak clearly and concisely: Narrate your actions to provide additional context for Replay.
• •Maintain a consistent visual style: Ensure the recorded application adheres to your design system.

💡 Pro Tip: A well-defined user flow is crucial for accurate code generation. Plan your recording in advance to ensure all necessary interactions are captured.

Step 3: Upload Your Video to Replay#

Navigate to the Replay platform and upload your video recording. Replay will automatically analyze the video and begin reconstructing the UI.

Step 4: Review and Refine the Generated Code#

Once the code generation process is complete, Replay will present you with a working application. Review the generated code to ensure it meets your expectations.

• •Inspect the component structure: Verify that the generated components align with your design system's component library.
• •Check the styling: Confirm that the visual elements adhere to your style guide.
• •Test the functionality: Ensure that all interactions function as expected.

typescript
// Example of a generated React component using a design system's Button component
import { Button } from '@my-design-system/components';

const MyComponent = () => {
  return (
    <Button variant="primary" onClick={() => alert('Clicked!')}>
      Click Me
    </Button>
  );
};

export default MyComponent;

Step 5: Customize and Extend the Application#

Replay provides several features to customize and extend the generated application:

• •Style Injection: Override existing styles to fine-tune the visual appearance.
• •Supabase Integration: Seamlessly connect your application to a Supabase backend for data storage and authentication.
• •Code Editing: Directly modify the generated code to add custom functionality.

📝 Note: While Replay strives to generate high-quality code, some manual adjustments may be necessary to fully integrate the application with your existing infrastructure.

typescript
// Example of using Supabase to fetch data
import { createClient } from '@supabase/supabase-js';

const supabaseUrl = 'YOUR_SUPABASE_URL';
const supabaseKey = 'YOUR_SUPABASE_ANON_KEY';
const supabase = createClient(supabaseUrl, supabaseKey);

const fetchData = async () => {
  const { data, error } = await supabase
    .from('your_table')
    .select('*');

  if (error) {
    console.error('Error fetching data:', error);
  } else {
    console.log('Data:', data);
    return data;
  }
};

Step 6: Product Flow Maps#

Replay automatically generates product flow maps from your video, giving you a visual representation of user journeys and interactions within your application. These maps are invaluable for identifying potential bottlenecks and optimizing the user experience.

Benefits of Using Replay for Design System Integration#

• •Accelerated Development: Generate working applications in minutes, significantly reducing development time.
• •Improved Consistency: Ensure that your applications adhere to your design system's principles, maintaining a consistent user experience.
• •Reduced Errors: Minimize manual coding errors by automating the UI reconstruction process.
• •Enhanced Collaboration: Facilitate communication between designers and developers by providing a shared understanding of the desired user flow.
• •Behavior-Driven Reconstruction: Replay understands the WHAT and the WHY behind user actions.

Addressing Common Concerns#

⚠️ Warning: Replay is not a magic bullet. While it can significantly accelerate development, it's essential to review and refine the generated code to ensure it meets your specific requirements.

Concern: The generated code might not be perfect.

Answer: Replay aims to generate high-quality, maintainable code. However, some manual adjustments may be necessary, especially for complex applications. Treat Replay as a powerful starting point, not a complete solution.

Concern: Replay might not understand all design system nuances.

Answer: Replay learns from the video input. The more closely the recorded application adheres to your design system, the more accurate the generated code will be.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features and usage. Paid plans are available for more extensive use and access to advanced features. Check the Replay pricing page for details.

How is Replay different from v0.dev?#

v0.dev relies on text prompts to generate code, while Replay analyzes video recordings. Replay excels at understanding user intent and reconstructing complex UIs based on observed behavior, leading to more accurate and functional code generation. Replay also features multi-page generation, Supabase integration, and style injection, which are not standard in LLM-only code generation tools.

What kind of video should I record?#

Record a clear, concise video of yourself interacting with a prototype or existing application that embodies your desired user flow. Ensure the application adheres to your design system's principles.

What if Replay doesn't generate the exact code I need?#

Replay provides tools for customizing and extending the generated code, including style injection and direct code editing. You can also integrate the generated code with your existing codebase.

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