Replay AI for automated UI component documentation using video assets

TL;DR: Replay AI automates UI component documentation by analyzing video recordings of user interactions, translating them into working code and comprehensive documentation, saving developers countless hours.

The dirty secret of software development is that documentation is almost always an afterthought. Beautifully crafted UI components sit undocumented, their purpose and usage known only to the original developers. This leads to duplicated effort, increased onboarding time, and a brittle codebase. Screenshot-to-code tools offer a partial solution, but they miss the crucial element: behavior. You can see the component, but you don't understand how it's used, the various states it can be in, or the intended user flow.

Enter Replay.

Replay AI leverages the power of video analysis and Gemini to reconstruct working UI components and automatically generate documentation based on observed user behavior. We call it "Behavior-Driven Reconstruction" - the video is the source of truth. Forget static screenshots. Replay understands the intent behind the interaction.

Why Video is King for UI Documentation#

Traditional documentation methods are inherently flawed. They rely on manual effort, are prone to becoming outdated, and often lack the nuance of real-world usage. Video, on the other hand, captures the entire context of a UI component in action.

Consider these benefits:

• •Real-world Usage: Videos showcase components in their natural habitat, demonstrating how users actually interact with them.
• •Dynamic States: Videos capture different states of a component based on user input, something static documentation struggles to convey.
• •Behavioral Context: Replay understands the sequence of actions, revealing the intended user flow and component interactions.
• •Reduced Maintenance: When the UI changes, simply re-record the interaction. Replay automatically updates the code and documentation.

Replay: From Video to Working Code & Documentation#

Replay's core innovation lies in its ability to analyze video recordings of UI interactions and translate them into:

1. •Functional UI Components: Reconstructed with high fidelity, ready to be integrated into your codebase.
2. •Automated Documentation: Generated from the observed user behavior, providing clear insights into component usage and purpose.
3. •Product Flow Maps: Visualization of user journeys through the UI.

How Replay Works: Behavior-Driven Reconstruction#

Replay doesn't just look at pixels; it understands the user's intent. By analyzing the sequence of actions, mouse movements, and UI state changes, Replay reconstructs the component's behavior. This is achieved through a multi-stage process:

1. •Video Analysis: Replay analyzes the video frame-by-frame, identifying UI elements and tracking user interactions.
2. •Behavioral Inference: Leveraging Gemini, Replay infers the user's intent and the component's underlying logic.
3. •Code Generation: Replay generates clean, well-structured code that accurately reflects the observed behavior.
4. •Documentation Generation: Replay automatically generates documentation based on the inferred behavior, including component descriptions, usage examples, and state transitions.

Comparison: Replay vs. Traditional Methods#

Let's compare Replay to traditional documentation methods and screenshot-to-code tools:

Hands-on Example: Documenting a Button Component#

Let's say you have a custom button component in your React application. You want to document its different states (e.g., default, hover, disabled) and how it interacts with the rest of the UI.

Step 1: Record the Interaction#

Simply record a video of yourself interacting with the button component, demonstrating its different states and usage scenarios.

Step 2: Upload to Replay#

Upload the video to Replay. The AI engine will begin analyzing the video.

Step 3: Review and Refine#

Replay generates the code and documentation. Review the output and make any necessary refinements. You can inject custom styles or integrate with your existing design system.

Step 4: Integrate into Your Workflow#

Copy the generated code and documentation into your codebase. Replay integrates seamlessly with popular frameworks and tools.

Here's an example of the type of code Replay might generate:

typescript
// Replay-generated React component
import React, { useState } from 'react';
import './CustomButton.css'; // Injected styles

interface ButtonProps {
  label: string;
  onClick: () => void;
  disabled?: boolean;
}

const CustomButton: React.FC<ButtonProps> = ({ label, onClick, disabled }) => {
  const [isHovered, setIsHovered] = useState(false);

  const handleMouseEnter = () => setIsHovered(true);
  const handleMouseLeave = () => setIsHovered(false);

  return (
    <button
      className={`custom-button ${disabled ? 'disabled' : ''} ${isHovered ? 'hovered' : ''}`}
      onClick={onClick}
      disabled={disabled}
      onMouseEnter={handleMouseEnter}
      onMouseLeave={handleMouseLeave}
    >
      {label}
    </button>
  );
};

export default CustomButton;

And here's an example of the documentation Replay might automatically generate:

markdown
## CustomButton Component

The `CustomButton` component is a reusable button with support for different states (default, hover, disabled).

### Usage

```jsx
<CustomButton label="Click Me" onClick={() => alert('Button clicked!')} />

Props#

• •
  text

  label
  : The text displayed on the button.
• •
  text

  onClick
  : A function that is called when the button is clicked.
• •
  text

  disabled
  : A boolean that indicates whether the button is disabled.

States#

• •Default: The button is in its normal state.
• •Hover: The button is hovered over by the mouse.
• •Disabled: The button is disabled and cannot be clicked.

💡 Pro Tip: Use consistent naming conventions for your components and props to improve the accuracy of Replay's code generation.

📝 Note: Replay automatically detects and documents the different states of the button based on the video analysis.

css
/* Example injected CSS styles */
.custom-button {
  background-color: #4CAF50;
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  cursor: pointer;
}

.custom-button:hover {
  background-color: #3e8e41;
}

.custom-button:disabled {
  background-color: #cccccc;
  cursor: not-allowed;
}

Replay's Key Features#

Replay offers a range of features designed to streamline the UI documentation process:

• •Multi-page Generation: Replay can handle complex, multi-page applications.
• •Supabase Integration: Easily integrate with your Supabase backend.
• •Style Injection: Inject custom styles to match your design system.
• •Product Flow Maps: Visualize user journeys through your UI.
• •Behavior-Driven Reconstruction: Understands user intent, not just visual elements.

⚠️ Warning: While Replay strives for high accuracy, it's always recommended to review and refine the generated code and documentation.

Replay vs. Screenshot-to-Code Tools#

Screenshot-to-code tools offer a limited solution, focusing only on the visual appearance of UI components. Replay goes beyond this, analyzing user behavior to understand the intent behind the interaction.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage. Paid plans are available for higher usage and advanced features.

How is Replay different from v0.dev?#

v0.dev focuses on generating UI components from text prompts. Replay analyzes video recordings of existing UI interactions to generate code and documentation, capturing the nuances of real-world usage. Replay focuses on understanding the behavior of the UI.

What frameworks does Replay support?#

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

Can I use Replay to document existing UI components?#

Yes! Simply record a video of yourself interacting with the component and upload it to Replay.

How accurate is Replay's code generation?#

Replay strives for high accuracy, but it's always recommended to review and refine the generated code. The accuracy depends on the clarity of the video and the complexity of the UI.

What are Product Flow Maps?#

Product Flow Maps are visualizations of user journeys through your UI, generated automatically by Replay based on the video analysis. They provide insights into how users navigate your application and identify potential areas for improvement.

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