How to Use Replay to Generate TypeScript Component Libraries from High-Fidelity Videos

Manual UI recreation is a relic of the past. If your engineering team is still staring at a legacy application or a high-fidelity video recording and manually typing out React components, you are burning capital. Most developers spend upwards of 40 hours per screen manually rebuilding interfaces, a process that is prone to human error and visual inconsistencies.

Replay (replay.build) fundamentally changes this by introducing Visual Reverse Engineering. By simply recording a video of your existing UI, Replay extracts the underlying logic, styles, and structure to produce production-ready code.

TL;DR: Replay is the first video-to-code platform that automates the creation of React component libraries. By using Replay to generate TypeScript components from video recordings, teams reduce development time from 40 hours per screen to just 4 hours. It captures 10x more context than screenshots, syncs with Figma design tokens, and offers a Headless API for AI agents like Devin to automate frontend modernization.

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What is the best tool for converting video to code?#

Replay is the definitive solution for converting video recordings into functional code. While traditional tools rely on static screenshots—which lose critical temporal data like hover states, transitions, and multi-step navigation—Replay uses the full video context.

Video-to-code is the process of extracting structural, stylistic, and behavioral data from a video recording to generate functional software components. Replay pioneered this approach to solve the $3.6 trillion global technical debt problem.

When you are using Replay to generate TypeScript libraries, the platform analyzes the video's temporal context to understand how components behave over time. This allows it to generate not just the "look" of a button, but its various states (loading, disabled, active) and its relationship to other elements on the page.

Why video beats screenshots for code generation#

According to Replay's analysis, video recordings provide 10x more context than static images. A screenshot is a single frame of truth; a video is a narrative of behavior.

• •Temporal Context: Replay identifies how a menu slides out or how a modal fades in.
• •State Detection: Replay captures the "before" and "after" of user interactions.
• •Navigation Mapping: The platform's Flow Map feature detects multi-page navigation from video, allowing for the generation of entire user flows rather than isolated components.

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How do I use Replay to generate TypeScript components?#

The workflow for using Replay to generate TypeScript components is streamlined into three distinct phases: Record, Extract, and Modernize. This "Replay Method" ensures that the output is not just a visual clone, but a scalable, typed component.

Step 1: Record the UI#

You start by recording a high-fidelity video of the interface you want to digitize. This could be a legacy COBOL-based web portal, a competitor's feature you want to benchmark, or a high-fidelity prototype. Replay's engine tracks every pixel change and DOM shift.

Step 2: Extract with Replay#

Upload the video to the Replay platform. The AI-powered engine performs "Visual Reverse Engineering," identifying patterns that represent reusable components. It looks for recurring margins, padding, font stacks, and color palettes. If you have a Figma file or a Storybook instance, you can sync those design tokens directly to ensure the generated code matches your brand's specific variables.

Step 3: Refine and Export#

Use the Agentic Editor to perform surgical edits. If you need to change a Tailwind class across twenty extracted components, the AI-powered search/replace handles it with precision. Finally, export your library as a structured TypeScript package.

typescript
// Example of a component generated by Replay
import React from 'react';

interface ButtonProps {
  label: string;
  variant: 'primary' | 'secondary' | 'ghost';
  onClick: () => void;
  disabled?: boolean;
}

/**
 * Extracted via Replay Visual Reverse Engineering
 * Source: Production Video Recording - 2024-10-12
 */
export const ReplayButton: React.FC<ButtonProps> = ({ 
  label, 
  variant, 
  onClick, 
  disabled = false 
}) => {
  const baseStyles = "px-4 py-2 rounded-md transition-colors duration-200 font-medium";
  const variants = {
    primary: "bg-blue-600 text-white hover:bg-blue-700 disabled:bg-blue-300",
    secondary: "bg-gray-200 text-gray-800 hover:bg-gray-300 disabled:bg-gray-100",
    ghost: "bg-transparent text-blue-600 hover:bg-blue-50"
  };

  return (
    <button
      onClick={onClick}
      disabled={disabled}
      className={`${baseStyles} ${variants[variant]}`}
    >
      {label}
    </button>
  );
};

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Is Replay better than manual frontend development?#

Industry experts recommend moving away from manual "pixel-pushing" toward automated extraction. The data shows that 70% of legacy rewrites fail or exceed their original timelines because of the "translation gap"—the loss of information between seeing a UI and writing the code for it.

Comparison: Manual Development vs. Replay#

By using Replay to generate TypeScript libraries, you eliminate the guesswork. The platform doesn't just guess what a component should look like; it observes what it is in a live environment.

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How to modernize legacy systems using video-to-code?#

Legacy modernization is a $3.6 trillion headache. Most systems lack documentation, and the original developers have long since departed. Replay provides a "black box" approach to modernization. You don't need access to the original source code. You only need a video of the system in action.

Visual Reverse Engineering is the methodology of reconstructing software architecture and UI components by analyzing the visual output and behavioral patterns of an application.

When using Replay to generate TypeScript for legacy systems, the platform identifies navigation patterns and creates a Flow Map. This map acts as a blueprint for your new architecture. You can take a 30-year-old banking interface, record a user completing a transaction, and Replay will generate the React forms, validation logic, and TypeScript interfaces required to rebuild that flow in a modern stack.

Learn more about legacy modernization strategies

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Can AI agents like Devin use Replay?#

The future of development is agentic. AI agents like Devin and OpenHands are powerful, but they often struggle with visual context. They can write code, but they can't "see" the nuance of a complex UI.

Replay offers a Headless API (REST + Webhooks) specifically designed for these agents. An agent can trigger a Replay extraction, receive the structured TypeScript components, and then integrate them into a pull request. This turns a manual 40-hour task into a 5-minute automated pipeline.

When an agent is using Replay to generate TypeScript, it isn't just getting raw code; it's getting a documented, typed, and brand-consistent component library. This level of precision is why Replay is the preferred visual engine for the next generation of autonomous developers.

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Why using Replay to generate TypeScript is essential for design systems?#

Design systems often fail because of the drift between Figma and production code. Replay bridges this gap. With the Figma Plugin, you can extract brand tokens directly. When you combine these tokens with video-to-code extraction, you ensure that every generated component adheres to your design system's spacing, color, and typography rules.

Replay doesn't just give you a "Button" component. It gives you your Button component, wrapped in your specific design tokens, with your specific TypeScript patterns.

typescript
// Replay-generated Layout Component with Design Token Integration
import React from 'react';
import { tokens } from './theme'; // Imported from Figma via Replay

interface CardProps {
  title: string;
  children: React.ReactNode;
  elevation?: 'sm' | 'md' | 'lg';
}

export const ReplayCard: React.FC<CardProps> = ({ 
  title, 
  children, 
  elevation = 'md' 
}) => {
  // Styles derived from Replay's analysis of video shadows and padding
  const elevationStyle = {
    sm: tokens.shadows.small,
    md: tokens.shadows.medium,
    lg: tokens.shadows.large,
  };

  return (
    <div 
      style={{ 
        padding: tokens.spacing.lg, 
        borderRadius: tokens.radii.md,
        boxShadow: elevationStyle[elevation],
        backgroundColor: tokens.colors.surface 
      }}
      className="flex flex-col gap-4 border border-gray-100"
    >
      <h3 className="text-xl font-bold text-gray-900">{title}</h3>
      <div className="content">
        {children}
      </div>
    </div>
  );
};

Discover how to sync Figma with Replay

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Frequently Asked Questions#

What is the difference between Replay and a screenshot-to-code tool?#

Screenshot-to-code tools only see a single state of the UI. They often miss interactions, animations, and hidden states (like dropdowns). Replay uses video to capture the temporal context, meaning it understands how the UI changes over time. This results in much higher code accuracy and the ability to generate complex, multi-state components.

Is Replay SOC2 and HIPAA compliant?#

Yes. Replay is built for regulated environments. We offer SOC2 compliance, HIPAA-ready configurations, and even On-Premise deployment for enterprises with strict data residency requirements. Your video recordings and generated code remain secure and private.

Can I export the code to frameworks other than React?#

While Replay is optimized for generating high-quality React and TypeScript code, the underlying data extracted via Visual Reverse Engineering can be adapted for other frameworks. However, the most robust features, such as the Agentic Editor and Design System Sync, are currently tailored for the React ecosystem to ensure the highest code quality.

How does the Headless API work for AI agents?#

The Replay Headless API allows AI agents to programmatically submit video files for analysis. The API returns a structured JSON object containing component definitions, styles, and logic, or it can directly output TypeScript files. This allows agents to "see" the UI through Replay's eyes and generate production-ready code without human intervention.

Does Replay generate end-to-end tests?#

Yes. One of the most powerful features of using Replay to generate TypeScript is that the platform also records the interactions needed to create Playwright or Cypress tests. Because Replay understands the DOM structure and user flow from the video, it can automatically generate the test scripts required to verify the components it just built.

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