Extracts resources and JavaScript from any installed Electron app (`.asar` bundle), restoring original sources from `.js.map` files when available or formatting minified code with Prettier otherwise. Use when user wants to "extract Electron app", "decompile Electron", "get the source code of <app>", "inspect app.asar", "看 Electron 应用源码", "提取 .asar", or asks how a desktop Electron app is built. Skips `node_modules` and supports both macOS and Windows.
git clone https://github.com/JimLiu/baoyu-skills.git--- name: baoyu-electron-extract description: Extracts resources and JavaScript from any installed Electron app (`.asar` bundle), restoring original sources from `.js.map` files when available or formatting minified code with Prettier otherwise. Use when user wants to "extract Electron app", "decompile Electron", "get the source code of <app>", "inspect app.asar", "看 Electron 应用源码", "提取 .asar", or asks how a desktop Electron app is built. Skips `node_modules` and supports both macOS and Windows. version: 1.119.0 metadata: openclaw: homepage: https://github.com/JimLiu/baoyu-skills#baoyu-electron-extract requires: anyBins: - bun - npx --- # Electron App Extract Extracts resources and code from an installed Electron app's `app.asar`. When a `.js.map` is present, restores the original source files from the embedded `sourcesContent`; otherwise formats the minified code with Prettier. Source-map paths are resolved relative to the `.js.map` file first, so bundled paths like `../../src/main.ts` restore to readable paths such as `restored/src/main.ts` instead of hashed placeholders. Always skips `node_modules`. Works on macOS and Windows. ## User Input Tools When this skill prompts the user, follow this tool-selection rule (priority order): 1. **Prefer built-in user-input tools** exposed by the current agent runtime — e.g., `AskUserQuestion`, `request_user_input`, `clarify`, `ask_user`, or any equivalent. 2. **Fallback**: if no such tool exists, emit a numbered plain-text message and ask the user to reply with the chosen number/answer for each question. 3. **Batching**: if the tool supports multiple questions per call, combine all applicable questions into a single call; if only single-question, ask them one at a time in priority order. Concrete `AskUserQuestion` references below are examples — substitute the local equivalent in other runtimes. ## Script Directory Scripts in `scripts/` subdirectory. `{baseDir}` = this SKILL.md's directory path. Resolve `${BUN_X}` runtime: if `bun` installed → `bun`; if `npx` available → `npx -y bun`; else suggest installing bun. Replace `{baseDir}` and `${BUN_X}` with actual values. | Script | Purpose | | ----------------- | ------------------------------------------------------------------------------ | | `scripts/main.ts` | App discovery + asar extraction + source-map restoration + Prettier formatting | ## When to use Use this skill whenever the user wants to look inside an installed Electron application or inspect its bundled code. Trigger phrases include: - "extract Electron app", "decompile this Electron app", "unpack app.asar" - "show me the source of <app>", "look inside <app>", "how is <app> built" - "get the source code of Codex / Cursor / Discord / Slack / VS Code / Notion / Obsidian / ChatGPT desktop" - "提取 Electron 应用", "看 <app> 的源码", "反编译 Electron", "解包 app.asar", "还原 source map" Both **app name** (e.g., `Codex`) and **absolute path** (e.g., `/Applications/Codex.app`, a `.asar` file, or a Windows install dir) are accepted. The script handles discovery for both platforms. ## Workflow **1. Determine the input.** Ask the user for the app name or path if they haven't given one. If they want a custom output directory, ask for that too. **2. Run the script.** ```bash ${BUN_X} {baseDir}/scripts/main.ts "<app>" [--output <dir>] [--asar <path>] [--force] ``` Start with `--dry-run` first if you're unsure whether discovery will find the right bundle — it prints the resolved paths and exits without touching the filesystem. **3. Handle the result.** - **Success** → report the output paths and the counts (extracted / restored / formatted). - **Multiple matches** → the script lists candidates and exits non-zero. Show the user the candidates, ask which one to use (via `AskUserQuestion` or the runtime equivalent), then re-run with the chosen absolute path. - **Existing non-empty output dir** → the script refuses without `--force`. Ask the user whether to overwrite (`--force`) or pick a new `--output` path. - **Unsupported platform / no match** → suggest passing `--asar /full/path/to/app.asar` if the user knows where the bundle lives. **4. Point the user at the result.** The default output dir is `~/Downloads/<AppName>-electron-extract/`. The most interesting subdirectory depends on what was found: - `restored/` exists → the original source tree was reconstructed from `.js.map` files; this is what to read first. - Only `extracted/` exists (no maps) → the JS/CSS in `extracted/` was Prettier-formatted in place; read from there. ## Source-map path restoration The script should preserve original source names and directory structure as much as the source map allows: - Resolve each `sources[]` entry with `sourceRoot` when present, then relative to the `.js.map` file's directory inside `extracted/`. - Collapse normal bundler-relative paths into the restored project tree. For example, `.vite/main/index.js.map` + `../../src/main.ts` becomes `restored/src/main.ts`. - If a source path climbs above `extracted/`, keep the readable remaining path under `restored/` instead of hashing it. For example, `.vite/main/index.js.map` + `../../../shared/src/lib/foo.ts` becomes `restored/shared/src/lib/foo.ts`. - Strip URL/query decorations from source names, including common `webpack://`, `file://`, and `?loader` suffixes. - Use `restored/__unknown/<hash>.<ext>` only when the source name is empty or cannot be reduced to a safe file path. - Continue skipping `node_modules` and `webpack/runtime/*` entries; these are bundler/runtime noise, not app sources. ## Usage ```bash # Extract by app name (default output: ~/Downloads/Codex-electron-extract/) ${BUN_X} {baseDir}/scripts/main.ts Codex # Extract by absolute path (works for .app bundles, install dirs, or .asar files) ${BUN_X} {baseDir}/scripts/main.ts "/Applications/Visual Studio Code.app" ${BUN_X} {baseDir}/scripts/main.ts "C:\Users\you\AppData\Local\Programs\codex" ${BUN_X} {baseDir}/scripts/main.ts --asar /Applications/Codex.app/Contents/Resources/app.asar Codex # Custom output ${BUN_X} {baseDir}/scripts/main.ts Codex --output ~/work/codex-source # Preview discovery without writing anything ${BUN_X} {baseDir}/scripts/main.ts Codex --dry-run # Overwrite an existing output dir ${BUN_X} {baseDir}/scripts/main.ts Codex --force # Machine-readable result (one JSON line on stdout) ${BUN_X} {baseDir}/scripts/main.ts Codex --json ``` ## Options | Option | Short | Description | Default | | ---------------- | ----- | --------------------------------------------------------------- | ---------------------------------------- | | `<app>` | | App name or absolute path. Required unless `--asar` is given. | — | | `--output` | `-o` | Output directory | `~/Downloads/<AppName>-electron-extract` | | `--asar` | | Override the resolved `.asar` path | auto-discovered | | `--force` | `-f` | Allow writing into a non-empty existing output dir | false | | `--skip-format` | | Skip Prettier formatting | false | | `--skip-restore` | | Skip source-map restoration | false | | `--no-unpacked` | | Don't copy `app.asar.unpacked/` alongside | false | | `--dry-run` | | Print resolved paths and exit without writing | false | | `--json` | | Emit one JSON-line summary on stdout (suppresses normal output) | false | ## Output layout ``` ~/Downloads/<AppName>-electron-extract/ ├── extract-report.json # JSON summary: counts, warnings, resolved paths ├── extracted/ # raw asar contents (JS/CSS Prettier-formatted when no map) │ └── ... # node_modules left untouched (skipped from format) ├── extracted.unpacked/ # copied from <asar>.unpacked/ if present │ └── ... # native modules (.node), large assets └── restored/ # only present if at least one .js.map was usable └── <original/source/tree> # rebuilt from sourcesContent in each .js.map ``` ## Notes - **node_modules** is always skipped — both for source-map restoration and Prettier formatting — because vendored dependencies are noise when inspecting an app. - **Source-map restoration** only works when the `.js.map` embeds `sourcesContent`. This is the common case for modern bundlers (webpack, esbuild, Vite, rollup). If a map references external `.ts`/`.js` files without embedding them, that map is skipped and the corresponding `.js` is Prettier-formatted instead. Skipped maps are listed in `extract-report.json` under `warnings`. - **Readable paths over hashes** — don't treat `../` segments in source-map paths as automatically unsafe. First resolve them from the map location and then sanitize the final output path so it still stays under `restored/`. Hash fallback is only for unusable source names. - **App discovery** searches `/Applications` + `~/Applications` on macOS, and `%LOCALAPPDATA%\Programs`, `%PROGRAMFILES%`, `%PROGRAMFILES(X86)%`, `%APPDATA%` on Windows. If discovery finds multiple matches, the script exits and lists them — re-run with an absolute path. On Linux or other platforms, pass `--asar /path/to/app.asar` explicitly. - **Safety** — the script refuses to write to `/`, the user home directly, or the current working directory, and refuses to populate an existing non-empty output dir without `--force`. - **No global installs** — `@electron/asar` and `prettier` are resolved on-the-fly via `npx -y`. First run will be slower while npx caches them.
[{"step":"Identify the Electron app's installation directory. On Windows, check `C:\\Users\\<USER>\\AppData\\Local\\<APP_NAME>\\app-<VERSION>\\resources\\app.asar` or `C:\\Program Files\\<APP_NAME>\\resources\\app.asar`. On macOS, look in `/Applications/<APP_NAME>.app/Contents/Resources/app.asar`.","tip":"Use tools like [Everything](https://www.voidtools.com/) (Windows) or `find` (macOS) to locate `app.asar` quickly."},{"step":"Copy the `app.asar` file to a working directory and rename it to `[APP_NAME].asar` (e.g., `slack.asar`).","tip":"Avoid modifying the original file to prevent corruption."},{"step":"Run the extraction command or use the AI skill with the prompt: 'Extract the source code from [APP_NAME].asar and save it to [OUTPUT_FOLDER]. Skip node_modules and restore original sources where possible.'","tip":"For CLI tools, use `npx asar extract slack.asar extracted_slack` (basic extraction) or integrate with Prettier for formatting."},{"step":"Review the extracted files in `[OUTPUT_FOLDER]`. Use a code editor (e.g., VS Code) to inspect the JavaScript files, especially those in `/src` or `/app` directories.","tip":"Look for `main.js` (main process), `renderer.js` (renderer process), and `preload.js` (bridge between main and renderer)."},{"step":"If source maps are missing, manually format minified files with Prettier using: `npx prettier --write extracted_slack/**/*.js`.","tip":"Use `--ignore-path` to skip `node_modules` or other irrelevant directories."}]
No install command available. Check the GitHub repository for manual installation instructions.
git clone https://github.com/JimLiu/baoyu-skills/tree/main/skills/baoyu-electron-extractCopy the install command above and run it in your terminal.
Launch Claude Code, Cursor, or your preferred AI coding agent.
Use the prompt template or examples below to test the skill.
Adapt the skill to your specific use case and workflow.
Extract the source code and resources from the Electron app '[APP_NAME]' (e.g., Slack, Discord, VS Code). Focus on restoring original JavaScript files using `.js.map` files where available. Skip `node_modules` and prioritize extracting the main application bundle (e.g., `app.asar`). If `.js.map` files are missing, format minified code with Prettier. Save the extracted files to a folder named '[OUTPUT_FOLDER]' (e.g., 'extracted_slack').
Successfully extracted the source code from the Electron app 'Discord' (version 0.0.309) to the folder 'extracted_discord'. The extraction process located and restored 1,247 original JavaScript files from `.js.map` sources, including the main application bundle (`app.asar`). Minified files without source maps (e.g., `renderer.js`) were automatically formatted with Prettier and saved in a readable structure. The extracted files include:
- Core application logic in `/src` (e.g., `main.js`, `renderer.js`)
- Static assets in `/assets` (e.g., images, fonts)
- Configuration files in `/config` (e.g., `package.json`, `asar.json`)
Skipped 42 files in `node_modules` as requested. The extracted code reveals Discord's use of React for its UI framework and Electron's `BrowserWindow` for rendering. A sample of the restored code (e.g., `index.js`) shows:
```javascript
// Main process entry point
const { app, BrowserWindow } = require('electron');
function createWindow() {
const win = new BrowserWindow({
width: 1280,
height: 720,
webPreferences: {
nodeIntegration: false,
contextIsolation: true,
}
});
win.loadFile('index.html');
}
app.whenReady().then(createWindow);
```
Note: Some proprietary or obfuscated code (e.g., analytics modules) remains minified due to missing source maps.skills-collection
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