MCP Integration

B4n1Web includes a Model Context Protocol (MCP) server with 33 tools for AI agent workflows.

What is MCP?

MCP (Model Context Protocol) lets AI agents (Claude, Cursor, etc.) use tools through a standardized interface. B4n1Web’s MCP server exposes browser automation as callable tools.

Quick Start

# Start MCP server
b4n1web mcp

This runs on stdio. Configure your AI client to use it:

Claude Desktop Config

{
  "mcpServers": {
    "b4n1web": {
      "command": "b4n1web",
      "args": ["mcp"]
    }
  }
}

Cursor Config

{
  "mcp": {
    "servers": {
      "b4n1web": {
        "command": "b4n1web",
        "args": ["mcp"]
      }
    }
  }
}

Available Tools (33)

Tool	Description
`goto`	Navigate to URL and extract content
`click`	Click element by CSS selector
`type_text`	Type text into element
`wait_for_selector`	Wait for element to appear

Content Extraction

Tool	Description
`evaluate`	Execute JavaScript
`screenshot`	Take screenshot
`pdf`	Generate PDF
`get_cookies`	Get all cookies
`clear_cookies`	Clear all cookies

Page Interaction

Tool	Description
`hover`	Hover over element
`scroll`	Scroll page/element
`select_option`	Select dropdown option
`key_press`	Press keyboard key
`upload_file`	Upload file to input
`download_file`	Download file from URL

Network

Tool	Description
`route`	Add network route handler
`unroute`	Remove route handler
`block_resources`	Block resource types
`wait_for_request`	Wait for request
`wait_for_response`	Wait for response

Browser State

Tool	Description
`set_viewport`	Set viewport size
`set_user_agent`	Override user agent
`set_geolocation`	Set geolocation
`emulate_device`	Emulate device
`frames`	List iframes
`iframe_text`	Get iframe text
`iframe_click`	Click in iframe
`iframe_type_text`	Type in iframe

Utility

Tool	Description
`performance_metrics`	Get Core Web Vitals
`save_state`	Save cookies/localStorage
`load_state`	Restore cookies/localStorage
`start_context`	Start incognito context
`quit_context`	Quit incognito context

Usage Example (AI Agent)

User: "Go to github.com and get the markdown of the trending page"

AI Agent calls:
1. goto(url="https://github.com/trending", mode="light")
2. Returns: {url, markdown, links, ...}

Daemon Mode

For persistent connections:

# Start daemon
b4n1web daemon start

# Check status
b4n1web daemon status

# Stop daemon
b4n1web daemon stop

The daemon runs the MCP server in background. Useful for long-running agent sessions.

Configuration

Environment Variables

export B4N1WEB_BINARY=/custom/path/b4n1web
export B4N1WEB_CHROMIUM=/usr/bin/chromium

Custom Chromium

The MCP server auto-downloads Chromium for Render mode tools. To use system Chromium:

export B4N1WEB_CHROMIUM=/usr/bin/chromium
b4n1web mcp

All 33 Tools Reference

Each tool returns structured JSON. Example:

{
  "goto": {
    "url": "https://example.com",
    "mode": "light",
    "wait_for": ".content"
  }
}

See CLI Reference for individual tool parameters.

Security

The MCP server runs with your user permissions. It can:

Access any URL
Take screenshots
Download files
Execute JavaScript

Only run with trusted AI agents.

B4n1Web — Agentic Browser Engine