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.

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.

Windows (%APPDATA%\Claude\claude_desktop_config.json):

{
  "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": {}
    }
  }
}

macOS / Linux (~/Library/Application Support/Claude/claude_desktop_config.json):

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

These commands are provided for users who prefer FastMCP's installer. The stdio JSON setup above is the recommended path.

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.

Mode	Tools	Use Case
Full (default)	97	Complete browser automation and debugging
Minimal (`--minimal`)	20	Core browser automation and interaction
Custom (`--disable-*`)	Your choice	Disable specific sections
Xpool safe (`--xpool-safe`)	83	Disable CDP function tools that trigger `Runtime.enable`

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:

Section	Tools	Description
`browser-management`	8	Core browser operations
`element-interaction`	12	Page interaction and manipulation
`element-extraction`	9	Element cloning and extraction
`file-extraction`	9	File-based extraction tools
`network-debugging`	10	Network monitoring and capture
`cdp-functions`	14	Chrome DevTools Protocol execution
`progressive-cloning`	10	Advanced element cloning
`cookies-storage`	3	Cookie management
`tabs`	5	Tab management
`debugging`	7	Debug and system tools
`dynamic-hooks`	10	AI-assisted network hooks

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.

Variable	Default	Meaning
`STEALTH_BROWSER_MCP_AUTH_TOKEN`	unset	Optional bearer token for HTTP transport. When set, HTTP clients must send `Authorization: Bearer <token>`.
`MCP_AUTH_TOKEN`	unset	Backward-compatible alias for `STEALTH_BROWSER_MCP_AUTH_TOKEN`.
`BROWSER_IDLE_TIMEOUT`	`600`	Global idle timeout in seconds before an unused browser instance is auto-closed. Set `0` to disable idle reaping globally.
`BROWSER_IDLE_REAPER_INTERVAL`	`60`	Background reaper check interval in seconds.
`BROWSER_ORPHAN_PROFILE_MAX_AGE`	`21600`	Startup cleanup threshold in seconds for stale `uc_*` temp profiles. Set `0` to disable this startup sweep.
`BROWSER_FILE_UPLOAD_ALLOWED_DIRS`	repo root	Directories that `file_upload()` may read from. Separate multiple roots with `;` on Windows or `:` on macOS/Linux.
`STEALTH_BROWSER_DEBUG`	`0`	Enable verbose debug logging to `stderr` when set to `1`.
`DEBUG`	`0`	Legacy alias for `STEALTH_BROWSER_DEBUG`.
`XPOOL_SAFE_MODE`	`0`	Disable the `cdp-functions` section at startup.
`PORT`	`8000`	Default HTTP port when `--port` is not provided.

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

Tool	Description
`spawn_browser()`	Create a stealth browser instance
`list_instances()`	List active browser sessions
`close_instance()`	Clean shutdown of a browser
`get_instance_state()`	Full browser state information
`navigate()`	Navigate to URLs
`go_back()`	Navigate back in history
`go_forward()`	Navigate forward in history
`reload_page()`	Reload current page

Tool	Description
`query_elements()`	Find elements by CSS selector or XPath
`click_element()`	Click an element
`type_text()`	Human-like typing with newline support
`paste_text()`	Instant text paste via CDP
`file_upload()`	Upload allowlisted local files to file inputs
`select_option()`	Select dropdown options
`get_element_state()`	Inspect element state
`wait_for_element()`	Wait for an element
`scroll_page()`	Scroll naturally
`execute_script()`	Run page JavaScript
`get_page_content()`	Read page HTML and text
`take_screenshot()`	Capture screenshots

Tool	Description
`list_network_requests()`	List captured network requests
`get_request_details()`	Inspect request headers and payload
`get_response_details()`	Inspect response metadata
`get_response_content()`	Read captured response content
`search_network_requests()`	Search captured requests
`export_network_data()`	Export captured network data
`import_network_data()`	Import captured network data
`set_network_capture_filters()`	Configure capture filters
`get_network_capture_filters()`	Read active capture filters
`modify_headers()`	Add or replace request headers

Tool	Description
`get_cookies()`	Read cookies
`set_cookie()`	Set cookies
`clear_cookies()`	Clear cookies

Tool	Description
`get_debug_view()`	Debug logs and statistics with pagination
`clear_debug_view()`	Clear debug logs
`export_debug_logs()`	Export logs as JSON, pickle, or gzip
`get_debug_lock_status()`	Inspect debug logger lock state
`hot_reload()`	Reload modules without server restart
`reload_status()`	Check module reload status
`validate_browser_environment_tool()`	Diagnose browser/platform compatibility

Tool	Description
`list_tabs()`	List open tabs
`switch_tab()`	Change active tab
`close_tab()`	Close a tab
`get_active_tab()`	Get current active tab
`new_tab()`	Create a new tab

Tool	Description
`extract_element_styles()`	Extract computed CSS properties
`extract_element_structure()`	Extract DOM structure
`extract_element_events()`	Extract event listeners
`extract_element_animations()`	Extract animations and transitions
`extract_element_assets()`	Extract images, fonts, videos, and assets
`extract_element_styles_cdp()`	Pure CDP style extraction
`extract_related_files()`	Find related CSS/JS files
`clone_element_complete()`	Complete element cloning
`extract_complete_element_cdp()`	Complete CDP-based element clone

Tool	Description
`clone_element_progressive()`	Initial lightweight element clone
`expand_styles()`	Expand styles on demand
`expand_events()`	Expand events on demand
`expand_children()`	Expand child nodes on demand
`expand_css_rules()`	Expand CSS rule data
`expand_pseudo_elements()`	Expand pseudo-elements
`expand_animations()`	Expand animation data
`list_stored_elements()`	List stored progressive clones
`clear_stored_element()`	Clear one stored element
`clear_all_elements()`	Clear all stored elements

Tool	Description
`clone_element_to_file()`	Save complete clone to file
`extract_complete_element_to_file()`	Save complete extraction to file
`extract_element_styles_to_file()`	Save styles to file
`extract_element_structure_to_file()`	Save structure to file
`extract_element_events_to_file()`	Save events to file
`extract_element_animations_to_file()`	Save animations to file
`extract_element_assets_to_file()`	Save assets to file
`list_clone_files()`	List saved clone files
`cleanup_clone_files()`	Clean up old clone files

Tool	Description
`list_cdp_commands()`	List available CDP commands
`execute_cdp_command()`	Run direct CDP commands
`add_script_to_evaluate_on_new_document()`	Install scripts before page JavaScript runs
`get_execution_contexts()`	List JavaScript execution contexts
`discover_global_functions()`	Find global JavaScript functions
`discover_object_methods()`	Discover methods on JavaScript objects
`call_javascript_function()`	Execute a discovered JavaScript function
`inspect_function_signature()`	Inspect function details
`inject_and_execute_script()`	Inject and run custom JavaScript
`create_persistent_function()`	Create functions that survive reloads
`execute_function_sequence()`	Execute ordered function calls
`create_python_binding()`	Create Python-to-JS bindings
`execute_python_in_browser()`	Translate Python to JavaScript with py2js and run it
`get_function_executor_info()`	Inspect executor state

Tool	Description
`create_dynamic_hook()`	Create a restricted Python network hook
`create_simple_dynamic_hook()`	Create hooks from common presets
`list_dynamic_hooks()`	List active hooks
`get_dynamic_hook_details()`	Inspect hook source and metadata
`remove_dynamic_hook()`	Remove a hook
`get_hook_documentation()`	Read request object and action docs
`get_hook_examples()`	View hook examples
`get_hook_requirements_documentation()`	Read matching and best-practice docs
`get_hook_common_patterns()`	Common hook patterns
`validate_hook_function()`	Validate hook code before use

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.

Feature	Stealth Browser MCP	Playwright MCP
Cloudflare / Queue-It style checks	Passes common JS challenges in testing	Commonly blocked
Hardened sites	Uses real Chrome-family browser instances through nodriver	Frequently flagged as automation
Login-walled pages	Can inspect loaded content and overlays through CDP	Often requires manual scripting
UI element cloning	CDP-accurate extraction	Limited
Network debugging	Full request/response inspection through AI tools	Basic
API reverse engineering	Payload inspection through chat	Manual tools only
Dynamic hook system	Restricted Python hooks for real-time interception	Not available
Modular architecture	11 sections, 20-97 tools	Fixed tool surface
Total tools	97 customizable tools	About 20

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.

Stealth Browser MCP

At a glance

README

Stealth Browser MCP

Sponsored by NodeMaven

Table of Contents

Demo

Features

Quickstart

1. Clone and install

2. Add to your MCP client

3. Test it

Agent Skill

Trust Model

Modular Architecture

Server Configuration

Toolbox

Stealth vs Playwright MCP

Troubleshooting

Examples

Showcase

Roadmap

Contributing

Support

License

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