Electron App Extract

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

{baseDir} = this SKILL.md's directory. Resolve ${BUN_X}: bun if installed; else npx -y bun; else suggest installing bun. Replace {baseDir} and ${BUN_X} with actual values.

Workflow

1. Determine the input. Accepts an app name (e.g., Codex) or absolute path (/Applications/Codex.app, a .asar file, or a Windows install dir). Ask for it if not given; ask for a custom output directory if they want one.

2. Run the script.

${BUN_X} {baseDir}/scripts/main.ts "<app>" [--output <dir>] [--asar <path>] [--force]

If unsure discovery will find the right bundle, run with --dry-run first (prints resolved paths, writes nothing).

3. Handle the result.

• Success → report output paths and counts (extracted / restored / formatted).
• Multiple matches → script lists candidates and exits non-zero. Ask the user which one (via AskUserQuestion or the runtime equivalent), then re-run with the chosen absolute path.
• Existing non-empty output dir → script refuses without --force. Ask whether to overwrite (--force) or pick a new --output.
• Unsupported platform / no match → suggest --asar /full/path/to/app.asar if the user knows where the bundle lives.

4. Point the user at the result (default ~/Downloads/<AppName>-electron-extract/):

• restored/ exists → original source tree reconstructed from .js.map files; read this first.
• Only extracted/ (no maps) → JS/CSS in extracted/ was Prettier-formatted in place; read from there.

Usage

${BUN_X} {baseDir}/scripts/main.ts Codex                                   # → ~/Downloads/Codex-electron-extract/
${BUN_X} {baseDir}/scripts/main.ts "/Applications/Visual Studio Code.app"  # .app bundle, install dir, or .asar
${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
${BUN_X} {baseDir}/scripts/main.ts Codex --output ~/work/codex-source
${BUN_X} {baseDir}/scripts/main.ts Codex --json                            # one JSON line on stdout

Options

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

Source-Map Path Restoration

Original source names and directory structure are preserved as far as the map allows:

• Each sources[] entry resolves with sourceRoot when present, then relative to the .js.map file's directory inside extracted/ — e.g. .vite/main/index.js.map + ../../src/main.ts → restored/src/main.ts.
• ../ segments are not treated as automatically unsafe: resolve from the map location first, then sanitize the final path so it stays under restored/. A path climbing above extracted/ keeps its readable remainder — .vite/main/index.js.map + ../../../shared/src/lib/foo.ts → restored/shared/src/lib/foo.ts.
• URL/query decorations are stripped (webpack://, file://, ?loader suffixes).
• restored/__unknown/<hash>.<ext> only when the source name is empty or can't be reduced to a safe file path.
• node_modules and webpack/runtime/* entries are skipped (bundler/runtime noise).

Notes

• node_modules is always skipped, for both source-map restoration and Prettier formatting.
• Restoration needs embedded sourcesContent (common for webpack, esbuild, Vite, rollup). Maps referencing external files without embedding them are skipped and the .js is Prettier-formatted instead; skipped maps appear in extract-report.json under warnings.
• App discovery: macOS /Applications + ~/Applications; Windows %LOCALAPPDATA%\Programs, %PROGRAMFILES%, %PROGRAMFILES(X86)%, %APPDATA%. Multiple matches → script exits and lists them; re-run with an absolute path. Linux/other: pass --asar /path/to/app.asar.
• Safety: 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 resolve on-the-fly via npx -y; first run is slower while npx caches them.