Superpowers Chrome - Claude Code Plugin

Direct browser control via Chrome DevTools Protocol. Two modes available:

1. Skill Mode - CLI tool for Claude Code agents (browsing skill)
2. MCP Mode - Ultra-lightweight MCP server for any MCP client

Features

• Zero dependencies - Built-in WebSocket, no npm install needed
• Idiotproof API - Tab index syntax (0, 1, 2) instead of WebSocket URLs
• Platform-agnostic - chrome-ws start works on macOS, Linux, Windows
• 17 commands covering all browser automation needs
• Complete documentation with real-world examples

Installation

/plugin marketplace add obra/superpowers-marketplace
/plugin install superpowers-chrome@superpowers-marketplace

Quick Start

# Find your plugin installation path (varies by marketplace and version)
# Common locations:
#   ~/.claude/plugins/cache/superpowers-marketplace/superpowers-chrome/<version>/skills/browsing
#   ~/.claude/plugins/cache/superpowers-chrome/skills/browsing

cd ~/.claude/plugins/cache/superpowers-marketplace/superpowers-chrome/*/skills/browsing
./chrome-ws start                        # Launch Chrome
./chrome-ws new "https://example.com"   # Create tab
./chrome-ws navigate 0 "https://google.com"
./chrome-ws fill 0 "textarea[name=q]" "test"
./chrome-ws click 0 "button[name=btnK]"

Port allocation: Chrome gets a dynamically allocated port (range 9222-12111) to avoid conflicts. Port assignment is persisted per profile in ~/.cache/superpowers/browser-profiles/{name}.meta.json. Override with --port=N flag or CHROME_WS_PORT env var. Multiple profiles can run in parallel on different ports.

Parallel MCPs on one host (3.0+): the bridge auto-disambiguates the default profile. The first MCP claims superpowers-chrome:9222, the next silently falls through to superpowers-chrome-2:9223, then -3:9224, etc., each driving its own Chrome with its own profile dir. To intentionally share a Chrome between processes (e.g., a chrome-ws CLI session + a Claude MCP attaching to it), set a fixed profile via CHROME_WS_PROFILE=name (env var) or call {action: "set_profile", payload: "name"} at runtime — explicit profiles share rather than disambiguate.

Windows tip: The tooling defaults to 127.0.0.1 for DevTools traffic. Override via CHROME_WS_HOST / CHROME_WS_PORT or --port=N if you forward Chrome elsewhere.

Linux/WSL2 tip: For headed mode (visible browser), the MCP server needs the DISPLAY environment variable. If show_browser doesn't work, configure "env": {"DISPLAY": ":0"} in your MCP server config. See mcp/README.md for details. Running as root or inside a container is detected automatically and disables Chrome's sandbox; on a headless box add CHROME_EXTRA_ARGS="--headless=new --disable-gpu".

Custom Chrome flags: Set CHROME_EXTRA_ARGS to a whitespace-separated list of flags that will be appended to the Chrome command line on launch. Useful for headless containers that need software WebGL:

CHROME_EXTRA_ARGS="--use-gl=angle --use-angle=swiftshader-webgl --enable-unsafe-swiftshader"

Windows Verification (November 7, 2025)

• node skills/browsing/chrome-ws start launched Chrome with remote debugging enabled on a fresh Windows 11 Pro install.
• node skills/browsing/chrome-ws tabs and node skills/browsing/chrome-ws navigate 0 https://example.com confirmed CLI control with the IPv4 default binding.
• codex exec -c "mcp_servers.superpowers-chrome.enabled=true" "List Chrome tabs via MCP to verify the Windows override patch." listed the Example Domain tab through the MCP server, demonstrating that the overrides also work through Codex.

Commands

• Setup: start (auto-detects platform)
• Tab management: tabs, new, close
• Navigation: navigate, wait-for, wait-text
• Interaction: click, fill, select
• Extraction: eval, extract, attr, html
• Export: screenshot, markdown
• Raw protocol: raw (full CDP access)

Dialog Handling

Pages that open JavaScript dialogs (alert, confirm, prompt, beforeunload), WebUSB/Bluetooth/Serial/HID device choosers, HTTP basic-auth challenges, or permission prompts (camera, microphone, notifications, geolocation, clipboard) no longer wedge the connection. The dialog is surfaced as a synthetic page response and the agent interacts with it using the existing click and type actions against a small dialog::* selector grammar.

What an agent sees

While a dialog is open, any page-targeted action (extract, screenshot, eval, attr, click <real-selector>, etc.) returns a clear refusal with the dialog content and instructions:

Page is behind a dialog. Handle dialog::accept or dialog::dismiss first.

# Dialog: confirm
Tab origin: https://example.com

> Are you sure you want to leave?

Buttons:
  - dialog::accept   (OK)
  - dialog::dismiss  (Cancel)

To interact:
  click selector="dialog::accept"
  click selector="dialog::dismiss"

Browser-targeted actions (list_tabs, new_tab, close_tab, etc.) pass through unaffected.

Selector grammar

Selector	Purpose
click dialog::accept	OK / Grant / Provide credentials, depending on dialog kind
click dialog::dismiss	Cancel / Deny
type dialog::prompt <value>	Stage prompt text; commit on dialog::accept
click dialog::device[id="…"]	Pick a device in the chooser (USB, BT, Serial, HID)
type dialog::username <value> / type dialog::password <value>	Basic-auth credentials

Worked example

# 1. Page on load: alert('Saved!')
extract payload=text
# → refused with synthetic dialog markdown

# 2. Dismiss
click selector="dialog::accept"

# 3. Page is interactive again
extract payload=text
# → returns the page text

Permission prompts (getUserMedia, Notification.requestPermission, geolocation, clipboard) are caught by a document_start JS-API shim and surfaced through the same flow.

See docs/superpowers/specs/2026-05-13-dialog-handling-design.md for the full design.

MCP Server Mode

Ultra-lightweight MCP server with a single use_browser tool. Perfect for minimal context usage with automatic page captures.

Installation Options

Option 1: NPX from GitHub (Recommended)

{
  "mcpServers": {
    "chrome": {
      "command": "npx",
      "args": [
        "github:obra/superpowers-chrome"
      ]
    }
  }
}

Option 1b: NPX with Headless Mode

{
  "mcpServers": {
    "chrome": {
      "command": "npx",
      "args": [
        "github:obra/superpowers-chrome",
        "--headless"
      ]
    }
  }
}

Option 2: Git Clone + Local Path (Current)

git clone https://github.com/obra/superpowers-chrome.git
cd superpowers-chrome/mcp && npm install && npm run build

{
  "mcpServers": {
    "chrome": {
      "command": "node",
      "args": [
        "/path/to/superpowers-chrome/mcp/dist/index.js"
      ]
    }
  }
}

Auto-Capture Features

DOM-changing actions (navigate, click, type, select, eval) automatically capture:

• Page HTML: Full rendered DOM state
• Page Markdown: Structured content extraction
• Screenshot: Visual page state
• DOM Summary: Token-efficient page structure
• Session Organization: Time-ordered captures in temp directory

Response format:

→ https://example.com (capture #001)
Size: 1200×765
Snapshot: /tmp/chrome-session-123/001-navigate-456/
Resources: page.html, page.md, screenshot.png, console-log.txt
DOM:
  Example Domain
  Interactive: 0 buttons, 0 inputs, 1 links
  Layout: body

Usage

{
  "action": "navigate",
  "payload": "https://example.com"
}

Get help: {"action": "help"} - Returns complete documentation

See mcp/README.md for complete documentation.

When to Use

Use Skill Mode when:

• Working with Claude Code agents
• Need full CLI control with 17 commands

Use MCP Mode when:

• Using Claude Desktop or other MCP clients
• Want minimal context usage (single tool)

Use Playwright MCP when:

• Need fresh browser instances
• Complex automation with screenshots/PDFs
• Prefer higher-level abstractions

Documentation

• SKILL.md - Complete skill guide
• EXAMPLES.md - Real-world examples
• chrome-ws README - Tool documentation

License

MIT