![Main article image](


alt="Article illustration 1"
loading="lazy">

)

A Shortcut to Where the Code Actually Lives

Modern React applications are dense, fast-moving organisms. Between component libraries, design systems, feature flags, and route-level layouts, simply answering “Where is this rendered?” can burn minutes or hours a week for every engineer on the team. React devtools help. Grep helps. Good naming helps. But they’re all indirect. React Source Lens, a lightweight open-source tool from [darula-hpp](https://github.com/darula-hpp/react-source-lens), takes a more opinionated stance: if a React component is on the screen, you should be able to jump straight to its source by hovering and pressing a single shortcut.

Hover. Cmd/Ctrl+Shift+O. Your editor opens at the exact file and line.

For teams buried in large React, Vite, CRA, or Next.js codebases, this is more than a visual trick—it’s a bid to make runtime UI inspection feel as direct and fluid as navigating code symbols in an IDE.

What React Source Lens Actually Does

At its core, React Source Lens is a development-time lens over your running UI:

  • Hover over any React component while the overlay is active.
  • Hit:
    • Cmd+Shift+O (macOS), or
    • Ctrl+Shift+O (Windows/Linux).
  • A modal pops up with:
    • File path and line number.
    • “Open in VS Code” (or your chosen editor) deep link.
    • “Copy Path” for quick sharing or searching.
  • The modal auto-dismisses after 10 seconds, or you can close it manually.
  • Use Cmd/Ctrl+Shift+L to toggle the overlay on or off.

It’s intentionally simple: no cluttered devtools, no custom inspector chrome. Just a mapping from “this element I’m looking at” to “the exact source location that defines it.”

![React Source Lens Demo](


alt="Article illustration 2"
loading="lazy">

)

How It Works (And Why It’s Clever)

React Source Lens leans on internals that many teams never touch directly.

  1. It inspects React Fiber nodes in the rendered tree.
  2. It uses React’s debug source metadata, which is typically available in development builds.
  3. A Babel plugin (optional but recommended) augments JSX elements with source attributes when necessary, improving reliability and path accuracy.

Because of that design, it works best when:

  • The app is running in development mode.
  • You’re using toolchains like Create React App or Vite that already preserve source information.
  • You’ve enabled the react-source-lens/babel-plugin to tighten the mapping.

This is a pragmatic exploitation of what React already knows about your code at build time and runtime. Instead of forcing developers to mentally correlate DOM, component trees, and file structures, it automates the jump.

For large organizations, this reduces:

  • Time-to-locate for unfamiliar components.
  • Friction in debugging and reviewing design system usage.
  • Cognitive overhead when traversing complex layout and composition patterns.

Setup in Plain Terms

For most React apps, getting started is deliberately minimal.

1. Install

npm install react-source-lens

2. Enable the Hook

Call useReactSourceLens once at the top level of your app in development:

import { useReactSourceLens } from 'react-source-lens';

export function AppRoot() {
  useReactSourceLens({
    projectRoot: '/absolute/path/to/your/project'
  });

  return <YourApp />;
}

You can also run it completely bare:

useReactSourceLens();

…but setting projectRoot unlocks accurate editor deep-links.

3. (Optionally) Add the Babel Plugin

For better source detection and stable paths, add:

{
  "plugins": ["react-source-lens/babel-plugin"]
}

Or in babel.config.js:

module.exports = {
  plugins: ['react-source-lens/babel-plugin']
};

This step is where Source Lens becomes more than “best effort” and starts behaving like a precise location service for your UI.

Editor Integration: Beyond Just VS Code

A detail that will matter to serious teams: React Source Lens doesn’t hardcode VS Code.

It supports editor auto-detection and explicit configuration:

  • Checks REACT_EDITOR and EDITOR environment variables.
  • Falls back to VS Code if nothing is set.

Supported editors include:

  • VS Code / code
  • WebStorm / IntelliJ
  • Atom
  • Sublime Text
  • Cursor
  • Windsurf

Configuration is straightforward:

useReactSourceLens({
  projectRoot: '/Users/you/projects/your-app',
  editor: 'windsurf' // or 'vscode', 'webstorm', 'intellij', 'atom', 'sublime', 'cursor'
});

Under the hood, it generates editor-specific URL schemes (e.g. vscode://file/path:line) so the jump-to-definition feels first-class in your local environment.

Handling Next.js: The Tricky but Important Part

Next.js is where many developer-experience tools go to die, usually on the altar of SWC vs Babel, file-system routing, and server/client boundaries.

React Source Lens takes a clear stance:

  • Next.js uses SWC by default, which does not support arbitrary Babel plugins.
  • To use React Source Lens effectively with Next.js, you switch Next.js to use Babel.

That means:

  1. Add a .babelrc to your Next.js project root:
{
  "presets": ["next/babel"],
  "plugins": ["react-source-lens/babel-plugin"]
}
  1. Create a client component provider:
// components/ReactSourceLensProvider.tsx
'use client';

import { useReactSourceLens } from 'react-source-lens';

export function ReactSourceLensProvider() {
  useReactSourceLens({
    projectRoot: '/absolute/path/to/your/nextjs/project'
  });

  return null;
}
  1. Register it in app/layout.tsx:
import { ReactSourceLensProvider } from '@/components/ReactSourceLensProvider';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="en">
      <body>
        <ReactSourceLensProvider />
        {children}
      </body>
    </html>
  );
}

The Babel plugin is aware of the Next.js App Router (app/ directory) conventions and adjusts relative paths accordingly—a small but crucial detail for monorepo and nested layout setups.

Is switching to Babel worth it? For some performance-obsessed builds, maybe not. But for many teams with complex UIs and high onboarding overhead, the trade-off will feel reasonable—especially in dev-only setups.

Why This Matters for Real Teams

Individually, React Source Lens looks like a neat DX trick. At scale, it’s a quiet challenge to how we navigate frontend systems.

Consider a typical week in a 50+ component Next.js or React app:

  • A designer flags a misaligned button variant.
  • A PM asks, “Where is this tooltip coming from?”
  • A new hire wants to understand how layout, theming, and routing fit together.

Today, the answers usually involve:

  • Searching by text, component names, or CSS classes.
  • Manually traversing the React DevTools tree.
  • Reverse-engineering file hierarchies that may or may not match runtime composition.

React Source Lens short-circuits that workflow by tying your running UI directly to the code that shaped it. It’s essentially:

  • A human-friendly manifestation of the React fiber tree.
  • A runtime-to-repo index specialized for UI work.

From a broader industry standpoint, it reflects three trends:

  1. Runtime-aware tooling: Devtools that treat the live app as the primary source of truth, not just the repo.
  2. DX as a competitive lever: Teams that reduce friction in understanding code win on onboarding, stability, and iteration speed.
  3. Open-source focus on pragmatic productivity: This isn’t abstract magic; it’s built on the metadata you already ship in dev.

For maintainers of design systems, micro-frontends, and large platform teams, this kind of visibility is not cosmetic—it’s governance. It clarifies which components are actually used where, and makes it cheaper to refactor responsibly.

From Hidden Wires to Visible Connections

The most frustrating bugs in modern React apps aren’t about syntax; they’re about indirection. Components wrap components, configs wrap configs, providers wrap everything—and the actual definition you care about is three abstractions away.

React Source Lens doesn’t remove that complexity, but it does expose the wiring. It transforms “I think this comes from…” into “I know exactly where this lives.”

It’s available now under the MIT license:

  • Source: https://github.com/darula-hpp/react-source-lens

For teams serious about developer experience, it’s the kind of tool that starts as a small convenience and quietly becomes non-negotiable.