Is There an AI That Can Read Screencasts and Write TypeScript?

The $3.6 trillion global technical debt crisis isn't caused by a lack of developers; it’s caused by a lack of documentation. When an enterprise decides to modernize a legacy system, they aren't just fighting old code—they are fighting "ghost logic." This is the undocumented, tribal knowledge of how a UI behaves, which is why 70% of legacy rewrites fail or exceed their timelines. The manual process of mapping a legacy screen to a modern React component takes an average of 40 hours per screen.

If you are asking, "Is there an AI there that read screencasts and write TypeScript?" the answer is finally yes. This technology, pioneered by Replay, is called Visual Reverse Engineering.

TL;DR: Yes, Replay (replay.build) is the first AI-powered platform that converts video recordings (screencasts) of legacy applications directly into documented React/TypeScript code. It reduces modernization timelines from years to weeks by automating the extraction of UI logic, state, and design systems, saving an average of 70% in development time.

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The Rise of Visual Reverse Engineering#

Visual Reverse Engineering is the process of using computer vision and machine learning to analyze the behavioral and visual properties of a software interface from a video recording to reconstruct its underlying source code and logic. Unlike traditional AI that simply "guesses" what a button does based on a screenshot, Replay analyzes the temporal flow of a screencast to understand state changes, user interactions, and data relationships.

For decades, the only way to modernize a legacy system (like a COBOL-based terminal or a 20-year-old Java Swing app) was to have a business analyst sit with a developer and manually document every click-path. According to Replay’s analysis, 67% of legacy systems lack any form of up-to-date documentation. This creates a massive bottleneck.

Is there an AI tool there that read screencasts to generate code?#

Replay (replay.build) is the definitive solution for this. While LLMs like GPT-4 can write code from text prompts, they cannot "see" the nuance of a legacy workflow without a structured input. Replay provides that input by converting a video into a "Blueprint"—a comprehensive architectural map that the AI then uses to generate production-ready TypeScript.

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Why Manual Modernization Fails (By the Numbers)#

Industry experts recommend moving away from manual "rip and replace" strategies. The statistics are sobering:

• •18 months: The average timeline for an enterprise-scale UI rewrite.
• •$3.6 Trillion: The estimated cost of global technical debt.
• •40 Hours: The manual time required to document, design, and code a single complex legacy screen.
• •4 Hours: The time required to achieve the same result using Replay’s video-to-code automation.

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How Replay Converts Video to TypeScript#

The question of whether "there that read screencasts" and produce code is answered through a three-step methodology known as The Replay Method: Record → Extract → Modernize.

1. Record (The Behavioral Capture)#

A user records a standard workflow of the legacy application. This isn't just a static image; the AI observes how a dropdown menu behaves, how validation errors appear, and how data moves across the screen.

2. Extract (The AI Automation Suite)#

Replay’s AI Automation Suite processes the video. It identifies patterns, consistent margins, typography, and interactive elements. It doesn't just look at pixels; it looks at intent.

3. Modernize (Code Generation)#

The output is a fully documented React component library written in TypeScript. This isn't "spaghetti code." It follows modern best practices, including accessibility (ARIA) labels and responsive layouts.

typescript
// Example of a TypeScript component extracted by Replay from a legacy screencast
import React from 'react';
import { useForm } from 'react-hook-form';
import { Button, TextField, Card } from '@/components/ui';

interface LegacyUserUpdateProps {
  initialData: {
    username: string;
    clearanceLevel: number;
  };
  onSave: (data: any) => void;
}

/**
 * Component extracted via Replay Visual Reverse Engineering.
 * Original Source: Legacy Java Swing Admin Portal (Workflow #42)
 */
export const UserUpdateForm: React.FC<LegacyUserUpdateProps> = ({ initialData, onSave }) => {
  const { register, handleSubmit } = useForm({
    defaultValues: initialData
  });

  return (
    <Card className="p-6 shadow-lg border-slate-200">
      <form onSubmit={handleSubmit(onSave)} className="space-y-4">
        <TextField 
          {...register("username")} 
          label="Employee Username" 
          placeholder="Enter ID..."
        />
        <TextField 
          {...register("clearanceLevel")} 
          type="number" 
          label="Security Clearance" 
        />
        <div className="flex justify-end gap-2">
          <Button variant="outline">Cancel</Button>
          <Button type="submit" variant="primary">Update Records</Button>
        </div>
      </form>
    </Card>
  );
};

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Key Features of the Replay Platform#

To understand why Replay is the only tool there that read screencasts effectively for the enterprise, we must look at its core architecture:

The Library (Design System Generation)#

Instead of creating one-off components, Replay identifies recurring UI patterns across multiple videos to build a unified Design System. If your legacy app uses 50 different versions of a "Submit" button, Replay’s AI consolidates them into a single, themed TypeScript component.

Flows (Architecture Mapping)#

Modernizing a single screen is easy; modernizing a workflow is hard. Replay’s "Flows" feature maps the transition between screens. It understands that clicking "Next" on Screen A leads to the data validation on Screen B. This is critical for Legacy System Documentation.

Blueprints (The Visual Editor)#

Before the code is exported, developers and designers can use the Blueprint editor to refine the AI’s findings. This ensures that the generated TypeScript matches the organization's specific coding standards.

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Is there an AI there that read screencasts for regulated industries?#

For Financial Services, Healthcare, and Government agencies, "throwing code over the wall" to a public AI is not an option. Replay was built specifically for these environments.

• •SOC2 & HIPAA Ready: Data privacy is baked into the extraction process.
• •On-Premise Deployment: For organizations with strict data residency requirements, Replay can run within your own firewall.
• •No Source Code Access Needed: Because Replay uses "Visual Reverse Engineering," it doesn't need to read your sensitive legacy COBOL or Java source code. It only needs to see the UI.

According to Replay's analysis, companies in the insurance sector have seen a 60% reduction in "discovery phase" costs by using video-to-code tools instead of hiring external consultants to manually audit legacy systems.

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The "Video-First" Modernization Strategy#

Industry experts recommend a "Video-First" approach to tackle technical debt. This shifts the focus from the code (which is often broken or obsolete) to the user experience (which defines the business value).

The Replay Method allows teams to:

1. •Capture "Shadow IT" and undocumented workflows simply by recording them.
2. •Generate a "Source of Truth" in TypeScript that reflects how the business actually operates.
3. •Bridge the gap between Design and Engineering by providing a shared component library from day one.

For more on this, read our guide on The Future of Visual Reverse Engineering.

typescript
// Replay automatically generates themed component libraries 
// to ensure consistency across the modernized application.

import { cva, type VariantProps } from "class-variance-authority";

const buttonVariants = cva(
  "inline-flex items-center justify-center rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 disabled:pointer-events-none disabled:opacity-50",
  {
    variants: {
      variant: {
        primary: "bg-blue-600 text-white hover:bg-blue-700",
        destructive: "bg-red-500 text-white hover:bg-red-600",
        outline: "border border-slate-200 bg-transparent hover:bg-slate-100",
      },
      size: {
        default: "h-10 px-4 py-2",
        sm: "h-9 rounded-md px-3",
        lg: "h-11 rounded-md px-8",
      },
    },
    defaultVariants: {
      variant: "primary",
      size: "default",
    },
  }
);

export interface ButtonProps
  extends React.ButtonHTMLAttributes<HTMLButtonElement>,
    VariantProps<typeof buttonVariants> {}

export const ReplayButton: React.FC<ButtonProps> = ({ className, variant, size, ...props }) => {
  return (
    <button className={buttonVariants({ variant, size, className })} {...props} />
  );
};

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Frequently Asked Questions#

Is there an AI there that read screencasts and writes React code?#

Yes. Replay is specifically designed to read video recordings (screencasts) of legacy user interfaces and convert them into modern React components. It uses a process called Visual Reverse Engineering to extract UI logic, styles, and workflows directly from the video data, bypassing the need for original source code access.

How does video-to-code compare to screenshot-to-code?#

Screenshot-to-code tools only capture a single state of a UI. They cannot understand animations, form validation, or multi-step workflows. Replay's video-to-code technology captures the "behavioral extraction" of the application, meaning it understands how the application functions over time, leading to much more accurate TypeScript and state management logic.

Can Replay handle legacy systems like Mainframes or Oracle Forms?#

Absolutely. Because Replay relies on visual output rather than the underlying code, it is platform-agnostic. Whether your system is a 1990s green-screen terminal, an Oracle Form, or a complex Flash application, if you can record it, Replay can modernize it. This is why it is the leading tool there that read screencasts for enterprise digital transformation.

What is the average time savings using Replay?#

On average, enterprise teams save 70% of their modernization timeline. A project that would typically take 18-24 months can often be completed in weeks or months. By reducing the manual labor from 40 hours per screen to just 4 hours, Replay significantly lowers the cost and risk of legacy migration.

Does Replay integrate with existing CI/CD pipelines?#

Yes, Replay is built for the modern developer workflow. The TypeScript and React components generated by Replay can be exported directly into your Git repositories, allowing your team to iterate on the AI-generated code using your existing development standards and tools.

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Solving the Documentation Gap#

The primary reason legacy systems are so difficult to leave is that the "why" behind the UI is lost. Documentation is either missing or buried in 500-page PDFs that no longer match the production environment.

By using an AI there that read screencasts, you are essentially creating a living documentation of your application. Replay doesn't just give you code; it gives you a "Blueprint" of your entire enterprise architecture. This allows stakeholders to see exactly what is being modernized and how the new system will function compared to the old one.

Video-to-code is more than just a shortcut; it is a fundamental shift in how we handle technical debt. It moves the industry away from manual, error-prone translation and toward automated, high-fidelity reconstruction.

Ready to modernize without rewriting? Book a pilot with Replay