Replay AI: Better UI Prototypes in React and Reusable Code With Firebase Authentication

TL;DR: Replay leverages video analysis and Gemini to generate React UI prototypes with Firebase authentication, offering a faster, more accurate alternative to screenshot-to-code tools.

The dream of turning design concepts into functional code is closer than ever. But existing screenshot-to-code tools often fall short, producing brittle, non-interactive UIs that require extensive manual rework. They see the what, but not the why. That's where behavior-driven reconstruction comes in, and that's where Replay shines.

From Video to Working Code: Introducing Behavior-Driven Reconstruction#

Imagine capturing a video of yourself navigating a desired user flow – clicking buttons, filling forms, and interacting with elements. Replay analyzes this video, understands the intent behind your actions, and generates clean, functional React code. No more painstakingly recreating designs from static images.

Replay uses a groundbreaking approach, leveraging Gemini and video analysis to go beyond visual recognition. It understands user behavior and reconstructs the underlying logic, resulting in more robust and maintainable code. This is "Behavior-Driven Reconstruction" in action.

Here's how Replay stacks up against traditional methods:

Building a React Prototype with Firebase Authentication using Replay#

Let's walk through creating a simple React application with Firebase authentication using Replay. We'll record a video of ourselves interacting with a basic authentication flow (sign-up, login, logout) and then use Replay to generate the code.

Step 1: Record Your User Flow#

Record a video demonstrating the desired authentication flow. This could include:

• •Navigating to a sign-up page
• •Entering email and password
• •Submitting the form
• •Navigating to a login page
• •Logging in with existing credentials
• •Logging out

Ensure the video is clear and captures all relevant interactions.

💡 Pro Tip: Speak clearly while recording, describing each action. This helps Replay understand the intent.

Step 2: Upload and Process with Replay#

Upload the video to Replay. The AI engine will analyze the video, identify UI elements, and infer the underlying logic. This process can take a few minutes depending on the video length and complexity.

📝 Note: Replay supports various video formats. Check the documentation for compatibility details.

Step 3: Review and Refine the Generated Code#

Once processing is complete, Replay will present you with the generated React code. This includes:

• •Component structure
• •UI elements (buttons, forms, etc.)
• •Event handlers (onClick, onSubmit, etc.)
• •Firebase authentication integration

Review the code carefully and make any necessary adjustments. Replay provides an intuitive interface for editing and refining the generated code.

⚠️ Warning: While Replay aims for high accuracy, manual review is always recommended to ensure the code meets your specific requirements.

Step 4: Firebase Configuration#

Replay can handle Firebase configuration automatically, but you may need to make some manual adjustments to your project.

1. •

   Install Firebase: If not already present, install Firebase in your React project:

   bash
   npm install firebase

2. •

   Initialize Firebase: Ensure your Firebase project is initialized. Replay may generate code similar to the following, but verify your

   text

   firebaseConfig
   matches your Firebase project settings:

   typescript
   // firebaseConfig.js
   import { initializeApp } from "firebase/app";
   import { getAuth } from "firebase/auth";
   
   const firebaseConfig = {
     apiKey: "YOUR_API_KEY",
     authDomain: "YOUR_AUTH_DOMAIN",
     projectId: "YOUR_PROJECT_ID",
     storageBucket: "YOUR_STORAGE_BUCKET",
     messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
     appId: "YOUR_APP_ID"
   };
   
   const app = initializeApp(firebaseConfig);
   export const auth = getAuth(app);

3. •

   Import Firebase: Import the necessary Firebase modules in your React components. Replay may generate code that already imports the necessary elements.

   typescript
   // Example: Authentication Component
   import React, { useState } from 'react';
   import { auth } from './firebaseConfig'; // Import the initialized auth object
   import { createUserWithEmailAndPassword, signInWithEmailAndPassword, signOut } from "firebase/auth";
   
   const Authentication = () => {
       const [email, setEmail] = useState('');
       const [password, setPassword] = useState('');
       const [error, setError] = useState('');
   
       const handleSignUp = async () => {
           try {
               await createUserWithEmailAndPassword(auth, email, password);
               alert('Successfully signed up!');
           } catch (err) {
               setError(err.message);
           }
       };
   
       const handleLogin = async () => {
           try {
               await signInWithEmailAndPassword(auth, email, password);
               alert('Successfully logged in!');
           } catch (err) {
               setError(err.message);
           }
       };
   
       const handleLogout = async () => {
           try {
               await signOut(auth);
               alert('Successfully logged out!');
           } catch (err) {
               setError(err.message);
           }
       };
   
       return (
           <div>
               <h2>Authentication</h2>
               <input
                   type="email"
                   placeholder="Email"
                   value={email}
                   onChange={(e) => setEmail(e.target.value)}
               />
               <input
                   type="password"
                   placeholder="Password"
                   value={password}
                   onChange={(e) => setPassword(e.target.value)}
               />
               <button onClick={handleSignUp}>Sign Up</button>
               <button onClick={handleLogin}>Log In</button>
               <button onClick={handleLogout}>Log Out</button>
               {error && <p>Error: {error}</p>}
           </div>
       );
   };
   
   export default Authentication;

Step 5: Run and Test#

Run your React application and test the authentication flow. Verify that users can sign up, log in, and log out correctly.

Benefits of Using Replay for UI Prototyping:#

• •Faster Development: Generate functional prototypes in minutes, not hours.
• •Improved Accuracy: Behavior-driven reconstruction ensures the code reflects the intended user experience.
• •Reduced Rework: Minimize manual coding and debugging.
• •Reusable Components: Replay generates clean, modular code that can be easily reused across your project.
• •Seamless Integration: Integrates with popular tools like Firebase, Supabase, and various styling libraries.

Replay: Beyond Screenshot-to-Code#

Replay offers a significant advantage over traditional screenshot-to-code tools by understanding user behavior. This leads to more accurate, interactive, and maintainable code. With features like multi-page generation, Supabase integration, and style injection, Replay streamlines the UI prototyping process.

Frequently Asked Questions#

Is Replay free to use?#

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

How is Replay different from v0.dev?#

While both tools aim to accelerate UI development, Replay's video-to-code approach offers a distinct advantage. v0.dev typically relies on text prompts and generates code based on those descriptions. Replay, on the other hand, analyzes actual user interactions captured in video, leading to more accurate and behaviorally-driven results. Replay also supports Firebase and Supabase integration out of the box.

Can Replay handle complex user flows?#

Yes, Replay can handle complex user flows spanning multiple pages and interactions. The key is to capture the entire flow clearly in the video recording.

What frameworks and libraries are supported?#

Replay primarily targets React development but is designed to be extensible to other frameworks in the future. It seamlessly integrates with popular libraries like Material UI, Tailwind CSS, and Firebase.

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