crxreader

Download and inspect any Chrome extension's source code from the command line.

Paste a Chrome Web Store URL (or bare extension ID), and crxreader downloads the CRX, unpacks it, names the folder after the extension, and opens it in your editor. Works on Linux, WSL, and Windows.

install

pip install requests

No other dependencies.

usage

python crxreader.py <url or extension id>

# paste the store url directly
python crxreader.py https://chromewebstore.google.com/detail/vortimo-osint-tool/mnakbpdnkedaegeiaoakkjafhoidklnf

# or just the id
python crxreader.py mnakbpdnkedaegeiaoakkjafhoidklnf

# open in a specific editor
python crxreader.py <url> --ide cursor

# extract without opening an editor
python crxreader.py <url> --no-open

save your defaults

Run this once and you won't need to pass flags again:

python crxreader.py --save-defaults --env wsl --output ~/extensions --ide code

Supported --env values: linux, wsl, windows

what you get

After running, your output folder contains the full unpacked extension source — named after the extension, not the raw ID string.

The terminal prints a summary from manifest.json:

  Vortimo OSINT-tool  v5.2.1  (mv3)
  ────────────────────────────────────────────────────
  service worker   background.bundle.js
  content script   contentScript.bundle.js
  permissions      storage, contextMenus, tabs, activeTab, webNavigation, webRequest, pageCapture
  host access      <all_urls>

  tip: paste js files into https://deobfuscate.relative.im/ to make them readable

wsl note

On WSL, the output is automatically copied to your Windows filesystem and the folder is opened in the Windows-side editor. The real Desktop path is resolved via PowerShell, so OneDrive-redirected Desktops work correctly.

supported editors

code, code-insiders, cursor, idea, pycharm, webstorm, subl, zed

You can also pass a full path to any executable with --ide

MCP server (if you dont want to use an AI extension in your IDE)

crxreader_mcp.py exposes the same pipeline as an MCP server so an AI model can download, unpack, and read Chrome extensions

install

pip install mcp requests

tools

tool	what it does
download_extension	downloads and unpacks an extension by URL or ID
list_files	lists all files in the unpacked folder
read_file	reads a specific file
search_files	searches across all source files for a pattern or regex

option 1 — Ollama via ollmcp (works on Windows WSL)

This is the recommended path on Windows. It connects your local Ollama models directly to the MCP tools via a terminal UI.

Install ollmcp:

pip install mcp-client-for-ollama

Create the server config:

mkdir -p ~/.config/ollmcp
cat > ~/.config/ollmcp/mcp_servers.json << 'EOF'
{
  "mcpServers": {
    "crxreader": {
      "command": "/path/to/venv/bin/python",
      "args": ["/path/to/crxreader_mcp.py"]
    }
  }
}
EOF

Run:

ollmcp --host http://$(ip route | grep default | awk '{print $3}'):11434 \
       --servers-json ~/.config/ollmcp/mcp_servers.json \
       --model qwen3:8b

Then just ask it:

inspect this extension: https://chromewebstore.google.com/detail/vortimo-osint-tool/mnakbpdnkedaegeiaoakkjafhoidklnf

The model will call download_extension automatically, return a manifest summary, then let you ask follow-up questions like search for fetch calls or read background.bundle.js.

Note on Windows: Claude Desktop on Windows has a known MSIX packaging bug that silently ignores local MCP server config. Use Ollama + ollmcp via WSL until Anthropic ships a fix.

option 2 — Claude Desktop (macOS and Linux only)

Add this to your Claude Desktop config at ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or ~/.config/Claude/claude_desktop_config.json (Linux):

{
  "mcpServers": {
    "crxreader": {
      "command": "/path/to/venv/bin/python",
      "args": ["/path/to/crxreader_mcp.py"]
    }
  }
}

Restart Claude Desktop. A hammer icon will appear in the chat input confirming the tools are connected. Then say:

inspect this extension: https://chromewebstore.google.com/detail/...

option 3 — SSE mode (any SSE-compatible MCP client)

Run the server in SSE mode:

python crxreader_mcp.py --transport sse --port 8000

Then point your client at http://localhost:8000/sse.