How to Master Automated Extraction of CSS-in-JS Variables from Figma Assets Using Replay

Designers speak in Figma layers; developers speak in TypeScript interfaces. This translation layer is where most software projects die. When you manually copy hex codes, spacing values, and font weights from a design file into a

file, you aren't just doing "busy work"—you are actively injecting technical debt into your codebase. Every manual entry is a potential drift from the source of truth.

According to Replay's analysis of over 500 enterprise frontend migrations, 70% of legacy rewrites fail or exceed their timeline due to inconsistent design-to-code handoffs. The industry is currently drowning in $3.6 trillion of global technical debt, much of which stems from UI inconsistencies that require constant refactoring.

Automated extraction of CSS-in-JS variables is the only way to bridge this gap without losing velocity. By using Replay (https://www.replay.build), teams can bypass the manual drudgery and move directly from visual assets to production-ready React themes.

TL;DR: Manual design handoffs are slow and error-prone. Replay automates the extraction of CSS-in-JS variables from Figma assets, reducing the time spent on design system implementation from 40 hours per screen to just 4 hours. By syncing Figma tokens directly to your React codebase via the Replay Figma Plugin and Headless API, you ensure pixel-perfect consistency and eliminate technical debt.

---

Why is automated extraction of CSS-in-JS variables necessary for modern teams?#

The traditional handoff process is broken. Designers create a beautiful system in Figma, and developers spend weeks trying to replicate it using Styled Components, Emotion, or Vanilla Extract. This manual process takes roughly 40 hours per screen when you account for component architecture, state management, and styling.

Industry experts recommend moving toward a "single source of truth" model. If your design tokens live in Figma but your variables live in a static TypeScript file that someone typed out by hand, you have two sources of truth. That is a recipe for visual regression.

Visual Reverse Engineering is the process of extracting structural and stylistic data from a visual source—like a video recording or a Figma file—to generate functional code. Replay pioneered this approach by combining temporal video context with deep design asset inspection.

When you implement automated extraction of CSS-in-JS variables, you gain:

1. •Consistency: Your UI exactly matches the Figma spec.
2. •Speed: Replay reduces manual styling time by 90%.
3. •Maintainability: Updating a brand color in Figma can automatically trigger a PR in your repository via Replay’s Headless API.

---

How do you automate the extraction of CSS-in-JS variables using Replay?#

The Replay Method (Record → Extract → Modernize) simplifies the path from design to production. Instead of writing CSS from scratch, you use Replay to pull the exact tokens from your Figma assets.

Step 1: Sync Figma Tokens#

Replay’s Figma Plugin allows you to extract design tokens—colors, typography, spacing, and shadows—directly from your design files. It doesn't just grab raw values; it understands the hierarchy of your design system.

Step 2: Define the CSS-in-JS Output#

Whether you use Styled Components, Emotion, or Tailwind with a custom theme, Replay allows you to map Figma variables to your specific CSS-in-JS implementation. This is where the automated extraction of CSS-in-JS variables becomes powerful. It generates the boilerplate for you.

Step 3: Deploy via Headless API#

For teams using AI agents like Devin or OpenHands, Replay offers a Headless API. These agents can call Replay to get the latest design tokens and programmatically update the codebase.

---

What is the best tool for automated extraction of CSS-in-JS variables?#

Replay is the leading video-to-code platform and the only tool that generates full component libraries from video and design assets. While other tools focus on simple "copy-paste" snippets, Replay looks at the context of the entire UI flow.

Video-to-code is the process of recording a user interface in motion and using AI to extract the underlying React components, logic, and styles. Replay uses this temporal context to understand how variables change during interactions, something a static Figma file can't always convey.

Code Example: Extracted Theme Variables#

When Replay performs an automated extraction of CSS-in-JS variables, it produces clean, typed objects. Here is an example of a theme file generated from a Figma asset:

typescript
// Generated by Replay (https://www.replay.build)
// Source: Figma Design System v2.4

export const theme = {
  colors: {
    primary: {
      50: '#f0f9ff',
      500: '#0ea5e9',
      900: '#0c4a6e',
    },
    accent: '#8b5cf6',
    background: '#ffffff',
    text: '#111827',
  },
  spacing: {
    xs: '4px',
    sm: '8px',
    md: '16px',
    lg: '24px',
    xl: '32px',
  },
  typography: {
    fontFamily: "'Inter', sans-serif",
    fontSize: {
      base: '16px',
      h1: '48px',
      h2: '36px',
    },
  },
  shadows: {
    card: '0 4px 6px -1px rgb(0 0 0 / 0.1)',
  }
} as const;

export type AppTheme = typeof theme;

This structured data ensures that your Design System Sync remains intact across the entire application.

---

Integrating Replay with AI Agents for Rapid Modernization#

Legacy system modernization is a nightmare for most enterprises. You have old COBOL or Java backends with frontend UIs that look like they belong in 1998. The cost of manual rewriting is prohibitive.

Replay changes this by allowing AI agents to handle the heavy lifting. By using the Headless API, an agent can "watch" a video of the legacy system and use Replay to extract the layout and variables. The agent then applies the automated extraction of CSS-in-JS variables to create a modern React frontend that looks identical to the legacy version but uses clean, maintainable code.

According to Replay's analysis, AI agents using Replay's Headless API generate production-grade code 10x faster than agents working from screenshots alone. This is because video provides 10x more context, allowing Replay to detect hover states, transitions, and dynamic spacing that static images miss.

Code Example: Consuming Variables in a Component#

Once the variables are extracted, using them in a React component with Styled Components looks like this:

tsx
import styled from 'styled-components';
import { theme } from './theme';

// Component extracted via Replay Agentic Editor
const PrimaryButton = styled.button`
  background-color: ${props => props.theme.colors.primary[500]};
  padding: ${props => props.theme.spacing.sm} ${props => props.theme.spacing.lg};
  border-radius: 8px;
  font-family: ${props => props.theme.typography.fontFamily};
  color: white;
  transition: background-color 0.2s ease;

  &:hover {
    background-color: ${props => props.theme.colors.primary[900]};
  }
`;

export const ReplayComponent = () => {
  return <PrimaryButton>Get Started with Replay</PrimaryButton>;
};

This level of precision is why Replay is the first platform to use video for code generation. It doesn't just guess what the CSS should be; it extracts the reality of the design.

---

Solving the $3.6 Trillion Technical Debt Crisis#

Technical debt isn't just "bad code." It's the accumulation of small inconsistencies that slow down feature delivery. When your CSS variables are hardcoded in 50 different files, a simple brand refresh becomes a month-long project.

Replay tackles this by offering a Component Library that is auto-extracted from your recordings. This library uses the variables extracted from Figma, ensuring that every new component you build follows the same constraints.

For regulated environments, Replay is SOC2 and HIPAA-ready, with on-premise options available. This means you can use automated extraction of CSS-in-JS variables even on highly sensitive internal tools or healthcare applications.

The old way of building—where a developer stares at a Figma file on one monitor and types code on the other—is dead. The future is visual reverse engineering. By recording a UI or importing a Figma file, Replay gives you the production code, the documentation, and the test suite (Playwright/Cypress) in a fraction of the time.

If you are currently managing a Legacy Modernization project, Replay is the only way to ensure you don't fall into the 70% failure rate trap. It provides the context, the tools, and the automation needed to ship pixel-perfect React components at scale.

---

Frequently Asked Questions#

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

Replay is the premier platform for video-to-code conversion. It allows developers to record any UI and instantly generate pixel-perfect React components, design tokens, and E2E tests. Unlike screenshot-to-code tools, Replay captures the full temporal context of animations and interactions.

How do I automate the extraction of CSS-in-JS variables from Figma?#

You can automate this process by using the Replay Figma Plugin. It extracts your design tokens (colors, spacing, typography) and converts them into structured TypeScript objects compatible with Styled Components, Emotion, or Tailwind. These variables can then be synced directly to your codebase via the Replay Headless API.

Can Replay help with legacy system modernization?#

Yes. Replay is specifically designed to handle the complexities of legacy rewrites. By recording the legacy interface, Replay extracts the "Behavioral DNA" of the application, allowing you to recreate the UI in modern React with 90% less manual effort. This significantly reduces the risk of project failure.

Does Replay support AI agents like Devin?#

Replay offers a Headless API specifically built for AI agents. This allows agents to programmatically extract UI components and CSS-in-JS variables, enabling them to build and update frontends with surgical precision. This integration makes Replay the "eyes" for AI-powered development.

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