Stealth Browser MCP

Undetectable browser automation for MCP-compatible AI agents.

Bypass Cloudflare, antibot systems, and social media blocks with real browser instances powered by nodriver + Chrome DevTools Protocol + FastMCP.

Demo
Features
Quickstart
Modular Architecture
Toolbox
Stealth vs Playwright MCP
Troubleshooting
Examples
Showcase
Roadmap
Contributing
Support
License

Demo

Stealth Browser MCP bypassing Cloudflare, cloning UI elements, and intercepting network traffic — all through AI chat commands.

Features

Antibot bypass — Works on Cloudflare, Queue-It, and other protection systems that block traditional automation
97 tools across 11 sections — From basic navigation to advanced CDP function execution
Modular loading — Run the full 97-tool arsenal or a minimal 20-tool core; disable what you don't need
Pixel-accurate element cloning — Extract complete elements with all CSS, DOM structure, events, and assets via CDP
Network interception — Inspect every request, response, header, and payload through your AI agent
Dynamic hook system — AI-generated Python functions that intercept and modify network traffic in real-time
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/CD pipelines with automatic environment detection
Browser support — Chrome, Chromium, and Microsoft Edge (automatic detection)
Clean MCP integration — No custom brokers or wrappers; works with Claude Code, Claude Desktop, Cursor, and any MCP client

Quickstart

1. Clone and install

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

# Activate virtual environment
# Windows:
venv\Scripts\activate
# Mac/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\"]}"

Mac/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 /path/to/stealth-browser-mcp/ with your actual project path.

Manual JSON configuration (Claude Desktop, Cursor, etc.)

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": {}
    }
  }
}

Mac/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": {}
    }
  }
}

FastMCP CLI (untested)

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

Modular Architecture

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

Mode	Tools	Use Case
Full (default)	97	Complete browser automation and debugging
Minimal (`--minimal`)	20	Core browser automation only
Custom (`--disable-*`)	Your choice	Disable specific sections

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

Use --debug or set STEALTH_BROWSER_DEBUG=1 to enable verbose server diagnostics on stderr. In normal MCP stdio usage, debug logging stays quiet by default to avoid noisy transport output.

HTTP transport security

stdio transport is recommended for local MCP clients and does not require HTTP auth.
HTTP transport remains unauthenticated by default for backward compatibility.
Do not expose unauthenticated HTTP transport outside trusted local or private networks.
Set STEALTH_BROWSER_MCP_AUTH_TOKEN to enable bearer-token auth for HTTP transport.
Clients must send Authorization: Bearer <token> after HTTP auth is enabled.

Browser lifecycle defaults

Idle browser instances are reaped automatically after 10 minutes by default.
Override per instance with spawn_browser(idle_timeout_seconds=...).
Disable idle reaping globally with BROWSER_IDLE_TIMEOUT=0.
Tune the background reaper cadence with BROWSER_IDLE_REAPER_INTERVAL.
Tune startup cleanup of abandoned temp profiles with BROWSER_ORPHAN_PROFILE_MAX_AGE (seconds).
Restrict local file uploads with BROWSER_FILE_UPLOAD_ALLOWED_DIRS.

Server Environment Variables

These are regular environment variables for the MCP server process itself. Set them wherever you launch src/server.py:

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 that are not in use by live browser processes. 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`.

Where to set them

Shell / local terminal

# macOS / Linux
export STEALTH_BROWSER_MCP_AUTH_TOKEN="replace-with-a-long-random-token"
export BROWSER_IDLE_TIMEOUT=900
export BROWSER_IDLE_REAPER_INTERVAL=30
export BROWSER_ORPHAN_PROFILE_MAX_AGE=43200
export BROWSER_FILE_UPLOAD_ALLOWED_DIRS="/Users/me/uploads:/Users/me/Documents"
python src/server.py

# Windows PowerShell
$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 config Put them in the server env block for your client.

{
  "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_IDLE_REAPER_INTERVAL": "30",
        "BROWSER_ORPHAN_PROFILE_MAX_AGE": "43200",
        "BROWSER_FILE_UPLOAD_ALLOWED_DIRS": "C:\\Users\\me\\uploads;C:\\Users\\me\\Documents"
      }
    }
  }
}

systemd / long-running service

[Service]
Environment="STEALTH_BROWSER_MCP_AUTH_TOKEN=replace-with-a-long-random-token"
Environment="BROWSER_IDLE_TIMEOUT=900"
Environment="BROWSER_IDLE_REAPER_INTERVAL=30"
Environment="BROWSER_ORPHAN_PROFILE_MAX_AGE=43200"
Environment="BROWSER_FILE_UPLOAD_ALLOWED_DIRS=/srv/stealth-browser/uploads:/srv/stealth-browser/shared"
ExecStart=/path/to/venv/bin/python /path/to/stealth-browser-mcp/src/server.py --transport http --host 0.0.0.0

Docker / container HTTP

docker run --rm -p 8000:8000 \
  -e STEALTH_BROWSER_MCP_AUTH_TOKEN="replace-with-a-long-random-token" \
  stealth-browser-mcp

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

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

Per-instance override

If you want a single browser instance to live longer or shorter than the server default, pass idle_timeout_seconds in spawn_browser(...).

Examples:

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.

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 interception
`cdp-functions`	14	Chrome DevTools Protocol execution
`progressive-cloning`	10	Advanced element cloning
`cookies-storage`	3	Cookie and storage management
`tabs`	5	Tab management
`debugging`	7	Debug and system tools
`dynamic-hooks`	10	AI-powered network hooks

Toolbox

Browser Management

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

Element Interaction

Tool	Description
`query_elements()`	Find elements by CSS/XPath
`click_element()`	Natural clicking
`type_text()`	Human-like typing with newline support
`paste_text()`	Instant text pasting via CDP
`file_upload()`	Upload allowlisted local files to file inputs
`scroll_page()`	Natural scrolling
`wait_for_element()`	Smart waiting
`execute_script()`	Run JavaScript
`select_option()`	Dropdown selection
`get_element_state()`	Element properties
`get_page_content()`	Full page HTML and text
`take_screenshot()`	Optimized page screenshots

Element Extraction (CDP-accurate)

Tool	Description
`extract_complete_element_cdp()`	Complete CDP-based element clone
`clone_element_complete()`	Complete element cloning
`extract_complete_element_to_file()`	Save complete extraction to file
`extract_element_styles()`	300+ CSS properties via CDP
`extract_element_styles_cdp()`	Pure CDP styles extraction
`extract_element_structure()`	Full DOM tree
`extract_element_events()`	React/Vue/framework listeners
`extract_element_animations()`	CSS animations/transitions
`extract_element_assets()`	Images, fonts, videos
`extract_related_files()`	Related CSS/JS files

File-Based Extraction

Tool	Description
`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
`clone_element_to_file()`	Save complete clone to file
`list_clone_files()`	List saved clone files
`cleanup_clone_files()`	Clean up old clone files

Network Debugging and Interception

Tool	Description
`list_network_requests()`	List captured network requests
`get_request_details()`	Inspect headers and payload for a request
`get_response_content()`	Get response data from a request
`modify_headers()`	Add custom headers to requests
`spawn_browser(block_resources=[...])`	Block tracking scripts, ads, etc.
`create_dynamic_hook()`	Create Python functions to intercept/modify requests
`create_simple_dynamic_hook()`	Quick hook creation with presets
`list_dynamic_hooks()`	List active hooks with statistics
`get_dynamic_hook_details()`	Inspect hook source code
`remove_dynamic_hook()`	Remove a hook
`get_hook_documentation()`	Request object structure and HookAction types
`get_hook_examples()`	10 detailed examples: blockers, redirects, proxies
`get_hook_requirements_documentation()`	Pattern matching and best practices
`get_hook_common_patterns()`	Ad blocking, API proxying, auth injection
`validate_hook_function()`	Validate hook code before deployment

CDP Function Execution

Tool	Description
`execute_cdp_command()`	Direct CDP commands (use snake_case)
`add_script_to_evaluate_on_new_document()`	Install pre-document scripts for API spoofing
`discover_global_functions()`	Find JavaScript functions
`discover_object_methods()`	Discover object methods (93+ methods)
`call_javascript_function()`	Execute any function
`inject_and_execute_script()`	Run custom JS code
`inspect_function_signature()`	Inspect function details
`create_persistent_function()`	Functions that survive reloads
`execute_function_sequence()`	Execute function sequences
`create_python_binding()`	Create Python-JS bindings
`execute_python_in_browser()`	Execute Python code via py2js
`get_execution_contexts()`	Get JS execution contexts
`list_cdp_commands()`	List available CDP commands
`get_function_executor_info()`	Get executor state info

Progressive Element Cloning

Tool	Description
`clone_element_progressive()`	Initial lightweight structure
`expand_styles()`	On-demand styles expansion
`expand_events()`	On-demand events expansion
`expand_children()`	Progressive children expansion
`expand_css_rules()`	Expand CSS rules data
`expand_pseudo_elements()`	Expand pseudo-elements
`expand_animations()`	Expand animations data
`list_stored_elements()`	List stored elements
`clear_stored_element()`	Clear specific element
`clear_all_elements()`	Clear all stored elements

Cookie and Storage

Tool	Description
`get_cookies()`	Read cookies
`set_cookie()`	Set cookies
`clear_cookies()`	Clear cookies
`get_instance_state()`	localStorage and sessionStorage snapshot
`execute_script()`	Read/modify storage via JS

Tabs

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

Page Analysis and Debugging

Tool	Description
`take_screenshot()`	Capture screenshots
`get_page_content()`	HTML and metadata
`get_debug_view()`	Debug info with pagination
`clear_debug_view()`	Clear debug logs
`export_debug_logs()`	Export logs (JSON/pickle/gzip)
`get_debug_lock_status()`	Debug lock status
`hot_reload()`	Reload modules without restart
`reload_status()`	Check module reload status
`validate_browser_environment_tool()`	Diagnose platform issues and browser compatibility

Stealth vs Playwright MCP

Feature	Stealth Browser MCP	Playwright MCP
Cloudflare / Queue-It	Consistently bypasses	Commonly blocked
Banking / Gov portals	Works	Frequently blocked
Social media automation	Full automation	Captchas and bans
UI element cloning	CDP-accurate extraction	Limited
Network debugging	Full request/response inspection via AI	Basic
API reverse engineering	Payload inspection through chat	Manual tools only
Dynamic hook system	AI-generated Python functions for real-time interception	Not available
Modular architecture	11 sections, 20–97 tools	Fixed ~20 tools
Total tools	97 (customizable)	~20

Tested on: LinkedIn, Instagram, Twitter/X, Amazon, banking portals, government sites, Cloudflare-protected APIs, Nike SNKRS, Ticketmaster, Supreme.

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 was printing to stdout, corrupting the MCP JSON-RPC protocol. This was fixed in #8. Pull the latest master branch.

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 / CI Run with --sandbox=false or ensure your environment supports sandboxing. The server auto-detects root and container environments and adjusts accordingly.

Orphan Chromium processes or uc_* temp profiles accumulate on long-running hosts The server now reaps idle browser instances automatically and performs startup cleanup of tracked orphan browser processes plus stale uc_* temp profiles. Set BROWSER_IDLE_TIMEOUT=0 to disable idle reaping if you want fully manual browser lifetime management.

Too many tools cluttering the AI chat Use --minimal for 20 core tools, 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, output a comparison table
UI cloning — Recreate a pricing section with exact fonts, styles, and interactions
Inventory monitoring — Watch a product page and alert when stock changes
API reverse engineering — Intercept requests, map endpoints, and inspect data flow

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:

License

MIT — see LICENSE.

Stealth BrowserStealth Browser

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