---
title: "Claude Desktop — Bundle Architecture"
description: "Documentation: Claude Desktop — Bundle Architecture"
type: reference
tags: [claude-desktop, bundles, asar, electron, reverse-engineering]
timestamp: 2026-06-24
---

# Claude Desktop — Bundle Architecture

Claude Desktop Electron app structure, extracted from ASAR (`/Applications/Claude.app/Contents/Resources/app.asar`).

## Build System

- **Version:** 1.14271.0
- **Build tool:** Electron Forge + Vite 6.4.2
- **Renderer:** React 18.3.1 + Tailwind CSS 3.4.19
- **Minifier:** Terser (local variables mangled, properties preserved)
- **Package:** `@ant/desktop`

## ASAR Structure

```
app.asar/
├── package.json                   # @ant/desktop, deps
├── harness-bootstrap.js           # Bezetacil runtime (added via repack)
├── .vite/
│   ├── build/
│   │   ├── index.js              # 14 MB — Electron Main Process (ALL logic)
│   │   ├── index.pre.js          # 811 KB — Preload script
│   │   ├── mainWindow.js         # 165 KB
│   │   ├── mainView.js           # 194 KB
│   │   └── ...
│   └── renderer/
│       ├── main_window/
│       │   ├── assets/
│       │   │   ├── main-Bh0l-09t.js      # 291 KB — React shell (react, react-dom, react-intl)
│       │   │   └── MainWindowPage-1yenKknx.js  # 13 KB — UI components
│       ├── about_window/         # About window bundle
│       ├── find_in_page/         # Find-in-page bundle
│       └── quick_window/         # Quick entry window
├── node_modules/
│   ├── @ant/claude-native/       # Native addons (.node, .dylib)
│   ├── ws/                       # WebSocket library
│   └── node-pty/                 # Terminal PTY
└── resources/
    └── office365-mcp/            # Office 365 MCP server
```

## 1p vs 3p — The Real Difference

**Not two separate bundles.** Same code with compile-time switches:

| Mechanism | 3p (prod) | 1p (internal) |
|-----------|-----------|--------------|
| `buildType` | `"prod"` | `"dev"` or `"staging"` |
| `isNestBuild` | `false` | `true` |
| `dzA()` (staging detect) | **no-op stub** `() => {}` | real function |
| `uF()` (URL base) | hardcoded `"https://claude.ai"` | `CLAUDE_AI_URL` env var |
| `hardcodedMainGrowthBookFeatures()` | `return null` | `return V3i` |
| `_vt()` (voice module) | `return Promise.resolve({})` | real module |
| `y4n` (Echo MCP) | `Object.freeze({})` empty | real module |

### URL Override (Dev)

```javascript
function uF() {
  if (buildType === "dev")
    return process.env.CLAUDE_AI_URL || config.claudeAiUrl || "https://claude.ai"
  if (isDeveloperApprovedDevUrlOverrideEnabled && process.env.CLAUDE_AI_URL)
    return process.env.CLAUDE_AI_URL
  return "https://claude.ai"
}
```

`isDeveloperApprovedDevUrlOverrideEnabled` requires Ed25519 signature via `CLAUDE_CDP_AUTH`.

## Remote Bundle (1p)

Loaded from `assets-proxy.anthropic.com/claude-ai/v2/assets/v1/`:

| File | Size | Content |
|---------|---------|----------|
| `index-BW29VlNm.js` | 7.2 MB | Complete React webapp (voice, UI, GrowthBook) |
| `c6a992d55-CvsZ6KID.css` | 758 KB | Design system @ant-cds + Tailwind |
| `vendor-ant-cds-D6IJ1PR1.css` | 204 B | CDS loader |

Extracted to `~/.bezetacil/workdir/claude-desktop/ion-dist/` via CDP.

### Voice Components in Remote Bundle

```
buildVoiceWebSocket, getVoice, setVoice, selectedVoice,
voiceContentBlocks, voiceSessionId
```

SFX: `/audio/voice/sfx/enter_voice_mode.mp3`, `exit_voice_mode.mp3`, `disconnected.mp3`

AudioWorklet: `audioSinkWorklet` with 5.76 MB ring buffer

## Persistent Workdir

```
~/.bezetacil/workdir/claude-desktop/
├── package.json              # From original ASAR
├── harness-bootstrap.js      # Bezetacil runtime
├── jsconfig.json             # Config for LSP (tsserver)
├── .vite/                    # ASAR bundles (main + renderer)
├── ion-dist/                 # Remote bundles extracted from 1p
│   ├── index-BW29VlNm.js     # 7.2 MB — webapp React
│   └── *.css                 # Design system
├── remote-scripts.json       # Remote script URLs
├── 1p-boot-features.json     # 1p desktopBootFeatures
├── 1p-features.json          # 1p scope scan
└── feature-flags.csv         # 226 analyzed features
```

## Design System

- **Framework:** Tailwind CSS 3.4.19 with custom HSL tokens
- **Components:** `@ant-cds` (Anthropic Design System) + `@radix-ui`
- **Icons:** `@phosphor-icons/react`
- **Fonts:** AnthropicSans, AnthropicSerif (variables)
- **Button variants:** `primary`, `secondary`, `danger`, `ghost`, `flat`, `unstyled`

## ASAR Repack

Tools used: `@electron/asar` (Node.js API), Python for Info.plist

Integrity hash: SHA256 of `headerString` (JSON), stored in `ElectronAsarIntegrity` in Info.plist (9 copies).

## References

- [[claude-desktop-feature-flags]] — Feature flag system
- [[claude-desktop-analysis-workflow]] — Analysis workflow
- [[bezetacil-toolset]] — ASAR pipeline and harness