> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/electron-userland/electron-builder/llms.txt
> Use this file to discover all available pages before exploring further.

# Two package.json Structure

> Learn how to use a two package.json structure to separate development and application dependencies

<Info>
  Since version 8, electron-builder rebuilds only production dependencies, so you are not forced to use the two package.json structure.
</Info>

## Overview

The two package.json structure separates development dependencies from application dependencies by using two separate `package.json` files:

1. **Development** (`./package.json`) - Root package.json for development environment and build scripts
2. **Application** (`./app/package.json`) - Application package.json distributed with the final packaged app

## Structure

### Root package.json (Development)

The `package.json` at the root of your project declares dependencies for your development environment and build scripts in `devDependencies`.

```json theme={null}
{
  "name": "my-electron-app",
  "version": "1.0.0",
  "scripts": {
    "postinstall": "electron-builder install-app-deps"
  },
  "devDependencies": {
    "electron": "^28.0.0",
    "electron-builder": "^24.0.0",
    "typescript": "^5.0.0"
  }
}
```

### App package.json (Production)

The `package.json` in the `app` directory declares your application dependencies. Only this directory is distributed with the final, packaged application.

```json app/package.json theme={null}
{
  "name": "my-electron-app",
  "version": "1.0.0",
  "main": "main.js",
  "dependencies": {
    "axios": "^1.6.0",
    "sqlite3": "^5.1.0"
  }
}
```

<Info>
  All metadata fields (`version`, `name`, etc.) should be in the `app/package.json`.
</Info>

## Why Use Two package.json?

### Native Module Compilation

Native npm modules (written in C, not JavaScript) need different compilation targets:

* **Application dependencies** - Compiled against Electron runtime
* **Development dependencies** - Compiled against local Node.js environment

The two package.json structure makes this separation trivial.

### Simplified File Management

No need to specify which files to include in the app using the [files configuration](/configuration/contents#files), because development files reside outside the `app` directory.

## Automatic Dependency Installation

To ensure dependencies are always updated based on both files, add a `postinstall` script to your development `package.json`:

```json theme={null}
{
  "scripts": {
    "postinstall": "electron-builder install-app-deps"
  }
}
```

This automatically triggers an `npm install` within your app directory whenever you install or update dependencies in the root directory.

## Related

* [Loading App Dependencies Manually](/guides/advanced/app-dependencies)
* [Files Configuration](/configuration/contents#files)