Stealth Browser MCP

Stealth browser automation for MCP-compatible AI agents.

Navigate Cloudflare challenges, anti-bot checks, and login walls with real Chrome-family browser instances powered by nodriver, Chrome DevTools Protocol, and FastMCP.

Sponsored by NodeMaven

Sponsored placement. NodeMaven is a paid sponsor of this project.

Table of Contents

• Sponsored by NodeMaven
• Demo
• Features
• Quickstart
• Agent Skill
• Trust Model
• Modular Architecture
• Server Configuration
• Toolbox
• Stealth vs Playwright MCP
• Troubleshooting
• Examples
• Showcase
• Roadmap
• Contributing
• Support
• License

Demo

Stealth Browser MCP passing a Cloudflare challenge, cloning UI elements, and inspecting network traffic through AI chat commands.

Features

• Anti-bot resistance - Has passed Cloudflare and Queue-It style challenges in testing; results vary by site, region, browser version, and detector version.
• 97 tools across 11 sections - From basic navigation to advanced CDP function execution.
• Modular loading - Run the full 97-tool surface or a minimal 20-tool core; disable sections you do not need.
• Pixel-accurate element cloning - Extract complete elements with CSS, DOM structure, events, animations, and assets via CDP.
• Network inspection - Inspect requests, responses, headers, payloads, and captured bodies through your AI agent.
• Dynamic hook system - Restricted Python hooks can intercept, block, redirect, fulfill, or modify request/response flows.
• CDP execution - Run JavaScript, direct CDP commands, and pre-document scripts through trusted local MCP clients.
• Instant text input - Paste large content via CDP or type with human-like keystrokes and newline support.
• Cross-platform - Windows, macOS, Linux, Docker, and CI environments with automatic browser/platform detection.
• Browser support - Chrome, Chromium, and Microsoft Edge with automatic executable discovery.
• Clean MCP integration - Works through standard MCP clients without custom brokers.

Quickstart

1. Clone and install

Requires Python 3.10+ and Chrome, Chromium, or Microsoft Edge.

git clone https://github.com/vibheksoni/stealth-browser-mcp.git
cd stealth-browser-mcp
python -m venv venv

# Windows
venv\Scripts\activate

# macOS / Linux
source venv/bin/activate

pip install -r requirements.txt

2. Add to your MCP client

Claude Code CLI (recommended):

Windows:

claude mcp add-json stealth-browser-mcp "{\"type\":\"stdio\",\"command\":\"C:\\path\\to\\stealth-browser-mcp\\venv\\Scripts\\python.exe\",\"args\":[\"C:\\path\\to\\stealth-browser-mcp\\src\\server.py\"]}"

macOS / Linux:

claude mcp add-json stealth-browser-mcp '{
  "type": "stdio",
  "command": "/path/to/stealth-browser-mcp/venv/bin/python",
  "args": ["/path/to/stealth-browser-mcp/src/server.py"]
}'

Replace the example path with your real clone path.

{
  "mcpServers": {
    "stealth-browser-mcp": {
      "command": "C:\\path\\to\\stealth-browser-mcp\\venv\\Scripts\\python.exe",
      "args": ["C:\\path\\to\\stealth-browser-mcp\\src\\server.py"],
      "env": {}
    }
  }
}

{
  "mcpServers": {
    "stealth-browser-mcp": {
      "command": "/path/to/stealth-browser-mcp/venv/bin/python",
      "args": ["/path/to/stealth-browser-mcp/src/server.py"],
      "env": {}
    }
  }
}

pip install fastmcp
fastmcp install claude-desktop src/server.py --with-requirements requirements.txt
fastmcp install claude-code src/server.py --with-requirements requirements.txt
fastmcp install cursor src/server.py --with-requirements requirements.txt

3. Test it

Restart your MCP client and ask your agent:

Use stealth-browser to navigate to https://example.com and take a screenshot.

Agent Skill

This repo includes an agent skill at skills/stealth-browser-mcp for clients that support Codex-style skills. It teaches agents the recommended tool order, state checks, pre-document CDP script usage, network debugging flow, and browser cleanup rules.

Use the skill when an LLM struggles to choose the right MCP tool or forgets to verify browser state after actions. If your client does not load repo-local skills automatically, add or symlink skills/stealth-browser-mcp into your client skills directory.

Trust Model

This server exposes powerful local browser-control primitives: CDP execution, page JavaScript execution, cookie/storage access, network interception, dynamic hooks, header mutation, navigation, and file uploads from allowlisted local paths.

Treat the MCP client or agent as the security principal. The recommended deployment is local stdio transport with a trusted desktop MCP client. If you use HTTP transport, set STEALTH_BROWSER_MCP_AUTH_TOKEN and do not expose unauthenticated HTTP outside trusted local or private networks.

Modular Architecture

Choose exactly what functionality you need. Run the full 97-tool suite or strip it down to the 20-tool core.

python src/server.py --minimal
python src/server.py --disable-cdp-functions --disable-dynamic-hooks
python src/server.py --list-sections
python src/server.py --debug
python src/server.py --transport http --host 127.0.0.1 --port 8000

Use --debug or set STEALTH_BROWSER_DEBUG=1 to enable verbose server diagnostics on stderr. Normal MCP stdio runs stay quiet by default to avoid corrupting JSON-RPC transport output.

Available sections:

Server Configuration

These are environment variables for the MCP server process. Set them in your shell, service manager, Docker environment, or MCP client env block.

PowerShell example:

$env:STEALTH_BROWSER_MCP_AUTH_TOKEN='replace-with-a-long-random-token'
$env:BROWSER_IDLE_TIMEOUT='900'
$env:BROWSER_IDLE_REAPER_INTERVAL='30'
$env:BROWSER_ORPHAN_PROFILE_MAX_AGE='43200'
$env:BROWSER_FILE_UPLOAD_ALLOWED_DIRS='C:\Users\me\uploads;C:\Users\me\Documents'
python src/server.py

MCP client env block:

{
  "mcpServers": {
    "stealth-browser-mcp": {
      "command": "C:\\path\\to\\stealth-browser-mcp\\venv\\Scripts\\python.exe",
      "args": ["C:\\path\\to\\stealth-browser-mcp\\src\\server.py"],
      "env": {
        "STEALTH_BROWSER_MCP_AUTH_TOKEN": "replace-with-a-long-random-token",
        "BROWSER_IDLE_TIMEOUT": "900",
        "BROWSER_FILE_UPLOAD_ALLOWED_DIRS": "C:\\Users\\me\\uploads;C:\\Users\\me\\Documents"
      }
    }
  }
}

HTTP client example:

from fastmcp import Client
from fastmcp.client.auth import BearerAuth

client = Client(
    "http://127.0.0.1:8000/mcp/",
    auth=BearerAuth("replace-with-a-long-random-token"),
)

Per-instance idle override:

• spawn_browser(idle_timeout_seconds=1800) keeps that instance for 30 minutes of inactivity.
• spawn_browser(idle_timeout_seconds=0) disables idle reaping for that one instance.

Toolbox

Stealth vs Playwright MCP

Detection results are point-in-time and depend on site policy, region, browser version, IP reputation, and detector version. See STEALTH_TESTS.md for the current manual snapshot and issue #25 for the proposed reproducible benchmark harness.

Troubleshooting

No compatible browser found Install Chrome, Chromium, or Microsoft Edge. The server auto-detects the first available browser. Run validate_browser_environment_tool() to diagnose.

Tools hang or return malformed JSON Debug output must not print to stdout during MCP stdio transport. Pull the latest master branch and keep debug logging disabled unless diagnosing a problem.

Need verbose diagnostics without noisy normal runs Use python src/server.py --debug or set STEALTH_BROWSER_DEBUG=1. Debug logs are emitted to stderr; normal MCP stdio runs stay quiet by default.

Browser crashes on Linux, Docker, or CI Run with --sandbox=false only if your environment requires it, or ensure the environment supports Chromium sandboxing. The server auto-detects root/container environments and adjusts launch arguments.

Orphan Chromium processes or uc_* temp profiles accumulate The server reaps idle browser instances automatically and performs startup cleanup of tracked orphan browser processes plus stale uc_* temp profiles. Set BROWSER_IDLE_TIMEOUT=0 only if you want fully manual browser lifetime management.

Too many tools cluttering the AI chat Use --minimal for 20 core tools, --xpool-safe for xpool-compatible operation, or selectively disable sections:

python src/server.py --disable-cdp-functions --disable-dynamic-hooks --disable-progressive-cloning

Module not found errors Make sure you activated the virtual environment and installed dependencies:

pip install -r requirements.txt

Examples

• Market research - Extract pricing and features from competitors, then output a comparison table.
• UI cloning - Recreate a pricing section with exact fonts, styles, assets, and interactions.
• Inventory monitoring - Watch a product page and alert when stock changes.
• API reverse engineering - Intercept requests, map endpoints, and inspect data flow.
• Form automation - Upload files from allowlisted paths and verify resulting page state.

All driven from a single AI agent conversation.

Showcase

Augment Code hero clone - A user asked Claude to clone the hero section from augmentcode.com. The agent spawned a stealth browser, navigated to the site, extracted the complete element via CDP (styles, structure, assets), and generated a pixel-accurate HTML recreation with responsive design and animations. The entire process took under two minutes of conversation.

View the recreation | Full walkthrough

Roadmap

See the live plan in ROADMAP.md. Contributions welcome.

Contributing

Read CONTRIBUTING.md and open a PR. First-time contributors welcome.

If this project saves you time, star the repo. It helps more than you think.

Support

If this tool saved you time or made you money, consider supporting development:

• Buy me a coffee

License

MIT - see LICENSE.