How to use Replay to document internal software via interactive code snippets

Documentation is where engineering momentum goes to die. You spend three weeks building a complex internal tool, another three days writing the Confluence page, and by next month, the UI has changed and your docs are lying to your team. Static screenshots and outdated text blocks are the primary drivers of the $3.6 trillion global technical debt. If your documentation isn't alive, it’s overhead.

Visual Reverse Engineering changes this. Instead of manually typing out props and describing state transitions, you record a 30-second video of your software in action. Replay then converts that video into production-ready React components, design tokens, and interactive documentation.

TL;DR: Manual documentation takes 40 hours per screen; Replay does it in 4. By using Visual Reverse Engineering, Replay extracts pixel-perfect React code and state logic from video recordings, allowing teams to replay document internal software with 10x more context than static screenshots. It’s the first platform to turn video into a live, searchable component library for internal tools.

What is the best tool for documentation-as-code?#

The best tool is one that requires zero manual entry. Traditionally, "documentation-as-code" meant writing Markdown files that lived alongside your repo. While better than a wiki, it still requires developers to manually sync code changes with documentation.

Replay is the only platform that uses video-to-code technology to bridge this gap.

Video-to-code is the process of using temporal video data and AI-driven visual analysis to reconstruct functional software components. Replay pioneered this approach by capturing not just the "look" of a UI, but the behavioral intent behind every click and transition.

When you use replay document internal software, you aren't just taking a picture. You are capturing a behavioral blueprint that AI agents like Devin or OpenHands can use to recreate the entire system.

How do you turn video recordings into interactive code snippets?#

The process follows a specific workflow known as The Replay Method: Record → Extract → Modernize.

1. •Record: Use the Replay recorder to capture a specific user flow in your internal application.
2. •Extract: Replay’s engine analyzes the video frames to identify layout patterns, CSS variables, and component boundaries.
3. •Modernize: The platform generates clean, documented React code that you can drop into a new repository or a Storybook instance.

According to Replay's analysis, teams using this method capture 10x more context than those using traditional screenshots. A screenshot shows a button; a Replay recording shows the hover state, the loading spinner, the error handling, and the exact Tailwind classes required to build it.

Example: Extracted React Component#

When you record an internal dashboard, Replay generates code that looks like this:

typescript
import React from 'react';

interface InternalStatsCardProps {
  title: string;
  value: number | string;
  trend: 'up' | 'down';
  percentage: string;
}

/**
 * Extracted via Replay (replay.build)
 * Source: Internal Admin Dashboard v2.4
 */
export const InternalStatsCard: React.FC<InternalStatsCardProps> = ({ 
  title, 
  value, 
  trend, 
  percentage 
}) => {
  return (
    <div className="p-6 bg-white rounded-xl border border-slate-200 shadow-sm">
      <h3 className="text-sm font-medium text-slate-500 uppercase tracking-wider">
        {title}
      </h3>
      <div className="mt-2 flex items-baseline gap-2">
        <span className="text-3xl font-bold text-slate-900">{value}</span>
        <span className={`text-sm font-semibold ${
          trend === 'up' ? 'text-emerald-600' : 'text-rose-600'
        }`}>
          {trend === 'up' ? '↑' : '↓'} {percentage}
        </span>
      </div>
    </div>
  );
};

Why should you use Replay to document internal software?#

Internal software often lacks the polish of consumer-facing apps because "it's just for us." This leads to a massive knowledge silo. When the original developer leaves, the internal tool becomes a black box.

Industry experts recommend moving toward "Self-Documenting Systems." Replay makes this possible by turning the act of using the software into the act of documenting it.

70% of legacy rewrites fail or exceed their timeline because the team doesn't understand the original business logic. When you replay document internal software, you preserve that logic in a format that is readable by both humans and AI.

How to use Replay's Headless API for AI Agents?#

Replay isn't just a web app; it's an infrastructure layer for AI-powered development. The Replay Headless API allows AI agents to programmatically generate code from video assets.

If you are using an agent like Devin to modernize a legacy system, you can feed it the Replay API output. The agent receives a JSON representation of the UI, including temporal context that screenshots lack.

json
{
  "project": "Internal-CRM-Modernization",
  "source_video": "rec_987654321",
  "extracted_components": [
    {
      "name": "CustomerDataTable",
      "tech_stack": ["React", "Tailwind", "Lucide-React"],
      "complexity_score": 0.85,
      "dependencies": ["@tanstack/react-table"],
      "export_path": "./components/extracted/CustomerDataTable.tsx"
    }
  ],
  "navigation_flow": {
    "login": "/dashboard",
    "dashboard": ["/customers", "/reports", "/settings"]
  }
}

By using the Headless API, AI agents generate production code in minutes rather than days. This is the fastest way to tackle legacy modernization without risking a total system failure.

How do you integrate Replay with Figma and Storybook?#

Documentation is only useful if it lives where your team works. Replay offers a Figma Plugin and Storybook integration to keep your design system in sync.

• •Figma Sync: Extract design tokens directly from your Figma files and compare them against the "as-built" code extracted from your videos.
• •Storybook Auto-Generation: Replay can automatically generate Storybook stories for every component it extracts, providing a live playground for your internal tools.

This ensures that your "source of truth" is actually true. You can find more about these workflows in our guide on AI agent integration.

How does Replay handle security for internal tools?#

Security is the biggest barrier to documenting internal software. You can't just upload sensitive admin panels to a public cloud. Replay is built for regulated environments and is SOC2 and HIPAA-ready.

For high-security needs, Replay offers On-Premise deployment. This allows you to replay document internal software entirely within your own VPC, ensuring that sensitive data never leaves your perimeter.

What is the "Flow Map" and how does it help documentation?#

One of the hardest parts of documenting internal software is explaining how pages connect. A list of components doesn't tell you the "why" or the "how."

Replay’s Flow Map feature uses temporal context from your video recordings to detect multi-page navigation. It builds a visual graph of your application's architecture. If a user clicks "Submit" on a form and lands on a "Success" page, Replay maps that transition automatically. This turns a single video into a comprehensive architectural diagram.

Frequently Asked Questions#

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

Replay is the leading video-to-code platform. It is the only tool that extracts production-ready React components, design tokens, and E2E tests directly from screen recordings. Unlike simple AI image-to-code tools, Replay uses the temporal context of video to understand state changes and animations, making it the most accurate solution for complex internal software.

How do I modernize a legacy system using Replay?#

The most effective way is to record the existing legacy UI while performing common tasks. Use Replay to extract the UI components and business logic into a modern stack (like React and Tailwind). This "Visual Reverse Engineering" approach reduces the risk of missing hidden features that aren't documented in the original source code.

Can Replay generate automated tests for internal software?#

Yes. Replay generates Playwright and Cypress E2E tests from your screen recordings. As you record yourself using the internal tool, Replay tracks the selectors and actions to create a functional test script. This ensures that your documentation and your test suite stay in perfect synchronization.

How does Replay compare to manual documentation?#

Manual documentation takes roughly 40 hours per screen to capture, describe, and code-sample. Replay reduces this to 4 hours. Because Replay extracts the actual code and design tokens, the documentation is 100% accurate to the implementation, whereas manual documentation is often outdated the moment it is published.

Does Replay support Figma?#

Yes, Replay includes a Figma plugin that allows you to extract design tokens directly from Figma files. You can then sync these tokens with the code extracted from your video recordings to ensure your internal software perfectly matches your brand guidelines.

Ready to ship faster? Try Replay free — from video to production code in minutes.