Replay: Code the UI

TL;DR: Replay revolutionizes UI development by using video analysis and behavior-driven reconstruction to generate working code directly from screen recordings.

The promise of AI-powered code generation has often fallen short. Screenshot-to-code tools deliver static representations, missing the crucial element of user behavior. What if you could capture the intent behind the UI and translate that into code?

That's the problem Replay solves. We're not just converting pixels; we're reconstructing the logic of your UI from video.

The Problem with Traditional UI Generation#

Existing methods, heavily reliant on static images, fail to capture the dynamic nature of user interactions. They can't infer the why behind the what. This leads to:

• •Incomplete UIs: Missing states, animations, and dynamic content.
• •Brittle Code: Difficult to maintain and adapt to changes.
• •Lack of Context: No understanding of the user's intended flow.

Consider a simple example: a user clicking a button that triggers a modal. A screenshot-based tool captures the button and the modal separately. It doesn't understand the relationship between them, the user's action that caused the modal to appear, or the data being passed.

Replay: Behavior-Driven Reconstruction#

Replay takes a fundamentally different approach. We analyze video recordings of user interactions, using Gemini to understand the user's behavior and reconstruct the UI accordingly. This "Behavior-Driven Reconstruction" allows us to:

• •Capture User Intent: Understand the purpose behind each interaction.
• •Generate Complete UIs: Include dynamic states, animations, and data bindings.
• •Create Maintainable Code: Reflect the underlying logic of the application.

Here's how Replay stacks up against other UI generation tools:

Key Features of Replay#

Replay isn't just about converting video to code; it's about providing a comprehensive platform for UI development. Here's a look at some of its key features:

Multi-Page Generation#

Replay can analyze videos spanning multiple pages and generate a complete application flow. This is crucial for complex applications where the UI is spread across different screens. Imagine recording a user flow that involves logging in, navigating to a dashboard, and creating a new item. Replay can reconstruct the entire flow into a single, cohesive codebase.

Supabase Integration#

Seamlessly integrate your Replay-generated UI with Supabase, a popular open-source Firebase alternative. This allows you to quickly connect your UI to a backend and start building data-driven applications. Replay can infer the data structures and relationships from the video and generate the necessary code to interact with your Supabase database.

Style Injection#

Customize the look and feel of your UI with style injection. Replay allows you to inject custom CSS or Tailwind classes to match your brand or design system. This provides a high degree of flexibility and control over the final output.

Product Flow Maps#

Visualize the user flow captured in the video with automatically generated product flow maps. These maps provide a clear overview of the application's structure and help you understand how users interact with your UI.

Getting Started with Replay: A Step-by-Step Guide#

Here's a practical guide to using Replay to generate code from a video recording.

Step 1: Record Your User Flow#

Use any screen recording tool to capture the user flow you want to convert into code. Ensure the video is clear and captures all relevant interactions.

💡 Pro Tip: Speak clearly while interacting with the UI. This helps Replay better understand your intent.

Step 2: Upload to Replay#

Upload your video to the Replay platform. Replay will begin analyzing the video and reconstructing the UI.

Step 3: Review and Customize#

Once the analysis is complete, review the generated code and customize it as needed. You can adjust styles, modify data bindings, and add custom logic.

Step 4: Integrate with Your Project#

Integrate the generated code into your existing project. Replay supports a variety of frameworks and libraries, making it easy to integrate with your preferred technology stack.

A Practical Example: Reconstructing a Simple To-Do App#

Let's say you've recorded a video of yourself interacting with a simple to-do app. The app allows you to add, delete, and mark tasks as complete. Here's how Replay would reconstruct the UI:

1. •Analysis: Replay analyzes the video and identifies the key UI elements: the input field, the add button, the task list, and the checkboxes.
2. •Behavior Inference: Replay understands that when you type into the input field and click the add button, a new task is added to the list. It also understands that clicking the checkbox marks a task as complete.
3. •Code Generation: Replay generates the following code (example in React):

typescript
// Example React component generated by Replay
import React, { useState } from 'react';

const TodoApp = () => {
  const [tasks, setTasks] = useState([]);
  const [newTask, setNewTask] = useState('');

  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
    setNewTask(e.target.value);
  };

  const handleAddTask = () => {
    if (newTask.trim() !== '') {
      setTasks([...tasks, { text: newTask, completed: false }]);
      setNewTask('');
    }
  };

  const handleCompleteTask = (index: number) => {
    const updatedTasks = [...tasks];
    updatedTasks[index].completed = !updatedTasks[index].completed;
    setTasks(updatedTasks);
  };

  return (
    <div>
      <input type="text" value={newTask} onChange={handleInputChange} />
      <button onClick={handleAddTask}>Add Task</button>
      <ul>
        {tasks.map((task, index) => (
          <li key={index}>
            <input
              type="checkbox"
              checked={task.completed}
              onChange={() => handleCompleteTask(index)}
            />
            <span>{task.text}</span>
          </li>
        ))}
      </ul>
    </div>
  );
};

export default TodoApp;

This code is a functional React component that allows you to add and complete tasks. Replay has inferred the state management, event handling, and UI rendering logic from the video.

⚠️ Warning: The generated code may require further refinement and optimization depending on the complexity of the UI.

Integrating with Supabase#

To integrate this to-do app with Supabase, Replay can generate the necessary API calls to store and retrieve tasks from your database. This would involve:

1. •Schema Inference: Replay infers the database schema based on the data displayed in the video.
2. •API Generation: Replay generates API endpoints for creating, reading, updating, and deleting tasks.
3. •Code Integration: Replay integrates these API calls into the React component, allowing you to persist your to-do list across sessions.

Benefits of Using Replay#

• •Faster Development: Generate UI code in seconds, saving you valuable development time.
• •Improved Accuracy: Capture user intent and create more complete and accurate UIs.
• •Reduced Maintenance: Generate code that reflects the underlying logic of the application, making it easier to maintain and adapt to changes.
• •Enhanced Collaboration: Use video recordings to communicate UI requirements and generate code collaboratively.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features. Paid plans are available for more advanced features and higher usage limits. Check the pricing page for the most up-to-date information.

How is Replay different from v0.dev?#

While v0.dev uses text prompts to generate UI components, Replay analyzes video recordings of user interactions to reconstruct entire application flows. Replay focuses on capturing user behavior and translating it into working code, while v0.dev focuses on generating individual components based on textual descriptions. Replay understands the user journey.

What frameworks and libraries does Replay support?#

Replay currently supports React, Vue, and Angular. Support for other frameworks and libraries is planned for future releases.

How secure is Replay?#

Replay uses industry-standard security practices to protect your data. All video recordings are encrypted in transit and at rest. You have complete control over your data and can delete it at any time.

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