ReverseCraft DevTools MCP

A powerful MCP (Model Context Protocol) server for browser debugging and reverse engineering. Provides AI coding assistants with comprehensive browser automation, JavaScript debugging, and network analysis capabilities.

Features

• JavaScript Debugging: Set breakpoints, step through code, inspect variables, and evaluate expressions
• IR Debugging: Debug JSVMP-protected code at the IR (Intermediate Representation) level with vmasm support
• Network Analysis: Monitor, search, and save network requests with full request/response details
• Page Automation: Navigate pages, interact with elements, and capture screenshots
• Console Monitoring: Access and filter console messages with full stack traces

Installation

Using npx (Recommended)

npx @reverse-craft/rc-devtools-mcp@latest

Using npm

npm install -g @reverse-craft/rc-devtools-mcp
rc-devtools-mcp

MCP Client Configuration

Kiro

Add to your Kiro MCP configuration (.kiro/settings/mcp.json):

{
  "mcpServers": {
    "rc-devtools": {
      "command": "npx",
      "args": ["@reverse-craft/rc-devtools-mcp@latest"]
    }
  }
}

Cursor

Add to your Cursor MCP configuration:

{
  "mcpServers": {
    "rc-devtools": {
      "command": "npx",
      "args": ["@reverse-craft/rc-devtools-mcp@latest"]
    }
  }
}

Claude Desktop

Add to your Claude Desktop configuration (claude_desktop_config.json):

{
  "mcpServers": {
    "rc-devtools": {
      "command": "npx",
      "args": ["@reverse-craft/rc-devtools-mcp@latest"]
    }
  }
}

With Custom Options

{
  "mcpServers": {
    "rc-devtools": {
      "command": "npx",
      "args": [
        "@reverse-craft/rc-devtools-mcp@latest",
        "--headless",
        "--viewport", "1920x1080"
      ]
    }
  }
}

Quick Start

1. Configure your MCP client with the server
2. Start a conversation with your AI assistant
3. Ask it to navigate to a website and debug JavaScript:

Navigate to https://example.com and set a breakpoint on line 10 of main.js

Or analyze network traffic:

List all network requests and show me the API calls

Available Tools

Input Automation

click - Click on an element

• uid (string, required): Element uid from page content snapshot
• dblClick (boolean, optional): Set to true for double click (default: false)

fill - Type text into input or select option

• uid (string, required): Element uid from page content snapshot
• value (string, required): Text to fill or option to select

press_key - Press a key or key combination

• key (string, required): Key or combination (e.g., "Enter", "Control+A", "Control+Shift+R")
  • Supported modifiers: Control, Shift, Alt, Meta

Navigation

navigate_page - Navigate to URL, go back/forward, or reload

• type (string, optional): Navigation type: url, back, forward, or reload
• url (string, optional): Target URL (required when type=url)
• ignoreCache (boolean, optional): Ignore cache on reload
• enableDebugger (boolean, optional): Enable JavaScript debugger after navigation (default: true)
• timeout (number, optional): Navigation timeout in milliseconds

new_page - Create a new browser page

• url (string, required): URL to load in the new page
• incognito (boolean, optional): Open in incognito window
• newWindow (boolean, optional): Open in new window
• userDataDir (string, optional): Independent user data directory path
• enableDebugger (boolean, optional): Enable JavaScript debugger (default: true)
• timeout (number, optional): Navigation timeout in milliseconds

list_pages - List all open pages

• No parameters

select_page - Select a page as active context

• pageIdx (number, required): Index of page to select (from list_pages)
• bringToFront (boolean, optional): Focus and bring page to top

Network

list_network_requests - List all network requests

• keyword (string, optional): Filter requests by keyword in URL, headers, or body
• pageSize (number, optional): Maximum requests to return
• pageIdx (number, optional): Page number (0-based)
• resourceTypes (array, optional): Filter by resource types (e.g., ["xhr", "fetch", "script"])
• includePreservedRequests (boolean, optional): Include requests from last 3 navigations (default: false)

get_network_request - Get details of a specific request

• reqid (number, optional): Request ID (omit to use currently selected request in DevTools)

save_network_request - Save request/response to file in raw HTTP format

• reqid (number, optional): Request ID (omit to use currently selected request)
• filePath (string, required): File path to save HTTP transaction
• responseBodyFilePath (string, optional): Separate file for binary response body
• saveRequestBody (boolean, optional): Save request body to separate file
• requestBodyFilePath (string, optional): File path for request body

save_static_resource - Save static resource to file

• reqid (number, required): Request ID containing the resource
• filePath (string, required): File path or directory (extension auto-detected from content type)

Debugging

Breakpoint Management

set_breakpoint - Set a JavaScript breakpoint at a specific line

• urlRegex (string, required): Regular expression to match script URL (e.g., ".*main\\.js.*")
• lineNumber (number, required): Line number (1-based, as shown in editors)
• columnNumber (number, optional): Target column number (0-based) for smart snapping
• snapRange (number, optional): Search range around target column for valid positions (default: 100)
• condition (string, optional): JavaScript expression - breakpoint only triggers when true

remove_breakpoint - Remove a breakpoint by its ID

• breakpointId (string, required): CDP breakpoint ID from set_breakpoint or list_breakpoints

list_breakpoints - List all active breakpoints

• searchTerm (string, optional): Filter breakpoints by ID or URL pattern
• pageSize (number, optional): Maximum breakpoints per page
• pageIdx (number, optional): Page number (0-based)

clear_all_breakpoints - Remove all breakpoints on the current page

• No parameters

get_possible_breakpoints - Find valid breakpoint locations (useful for minified code)

• urlRegex (string, required): Regular expression to match script URL
• lineNumber (number, required): Line number to search (1-based)
• startColumn (number, optional): Start column for search range (0-based)
• endColumn (number, optional): End column for search range (0-based)
• maxCount (number, optional): Maximum locations to return (default: 20)

Execution Control

step_into - Step into a function call

• maxCallStackDepth (number, optional): Max call stack frames to display (default: 4)
• contextLines (number, optional): Lines of code context before/after (default: 2)
• maxLocalVariables (number, optional): Max local variables to display (default: 5)
• showStatus (boolean, optional): Whether to show debug status (default: true)

step_over - Step over to the next line

• maxCallStackDepth (number, optional): Max call stack frames to display (default: 4)
• contextLines (number, optional): Lines of code context before/after (default: 2)
• maxLocalVariables (number, optional): Max local variables to display (default: 5)
• showStatus (boolean, optional): Whether to show debug status (default: true)

step_out - Step out of the current function

• maxCallStackDepth (number, optional): Max call stack frames to display (default: 4)
• contextLines (number, optional): Lines of code context before/after (default: 2)
• maxLocalVariables (number, optional): Max local variables to display (default: 5)
• showStatus (boolean, optional): Whether to show debug status (default: true)

resume_execution - Resume paused execution

• No parameters

Inspection & Evaluation

get_debugger_status - Get current debugger state with call stack and variables

• frameIndex (number, optional): Call frame index to inspect (default: 0)
• contextLines (number, optional): Lines of code context (default: 5)
• maxPropertiesPerScope (number, optional): Max properties per scope to display
• skipScopeVariables (boolean, optional): Skip scope variable inspection
• useObjectPreviews (boolean, optional): Use object previews instead of full retrieval
• maxOutputLines (number, optional): Maximum output lines (default: 100)
• maxCallStackFrames (number, optional): Max call stack frames (default: 20)
• maxLineLength (number, optional): Max characters per line (default: 500)
• showIRContext (boolean, optional): Show IR context if paused in JSVMP code (default: true)

evaluate_on_call_frame - Evaluate JavaScript expression in a specific call frame

• expression (string, required): JavaScript expression to evaluate
• frameIndex (number, optional): Call frame index (default: 0)
• maxOutputChars (number, optional): Max output characters (default: 10000)
• filepath (string, optional): Save result to file instead of displaying

get_scope_variables - Get detailed variable information from a scope

• frameIndex (number, optional): Call frame index (default: 0)
• scopeType (string, optional): Filter by scope type (local, closure, block, script, global, etc.)
• variableName (string, optional): Get specific variable by name
• searchTerm (string, optional): Search variables by name
• pageSize (number, optional): Max variables per page
• pageIdx (number, optional): Page number (0-based)
• maxDepth (number, optional): Max depth for nested objects (default: 3)
• maxOutputLines (number, optional): Max output lines (default: 100)
• saveToFile (string, optional): Save output to file path
• maxLineLength (number, optional): Max characters per line (default: 1000)

save_scope_variables - Save all scope variables to a JSON file

• filePath (string, required): Output file path
• frameIndex (number, optional): Call frame index (default: 0)
• includeGlobal (boolean, optional): Include global scope (default: false)

disable_debugger - Disable the debugger and remove all breakpoints

• No parameters

XHR/Fetch Breakpoints

set_xhr_breakpoint - Set a breakpoint on XHR/Fetch requests

• urlPattern (string, required): URL substring to match (empty string matches all requests)

remove_xhr_breakpoint - Remove an XHR breakpoint

• urlPattern (string, optional): URL pattern to remove (omit to remove all XHR breakpoints)

list_xhr_breakpoints - List all active XHR breakpoints

• No parameters

Screenshots & Snapshots

take_screenshot - Capture a screenshot

• format (string, optional): Image format: png, jpeg, or webp (default: png)
• quality (number, optional): Compression quality for JPEG/WebP (0-100, higher = better quality)
• uid (string, optional): Element uid to screenshot (omit for full page)
• fullPage (boolean, optional): Capture full page instead of viewport (incompatible with uid)
• filePath (string, optional): Save to file instead of attaching to response

take_snapshot - Take a text snapshot of the page

• verbose (boolean, optional): Include all information from the full a11y tree (default: false)
• filePath (string, optional): Save to file instead of attaching to response
• search (string, optional): Filter elements matching this text (case-insensitive)
• pageSize (number, optional): Number of elements per page for pagination
• pageIdx (number, optional): Page index (0-based) for pagination

IR Debugging (VMASM)

load_vmasm - Load a vmasm file and configure script interception

• filePath (string, required): Path to the vmasm file (absolute or relative)
• sourceFilePath (string, optional): Path to the original JS source file (if not in vmasm @source directive)
• Note: Refresh the page after loading for the debug script to take effect

get_vm_state - Get the current virtual machine state when paused

• maxStackItems (number, optional): Maximum stack items to display (default: 20)
• maxConstants (number, optional): Maximum constants to display (default: 10)
• contextLines (number, optional): Number of bytecode instructions to show before/after current (default: 5)
• Returns: JSVMP registers, transform variables, opcode listing, virtual call stack, and scope chain

set_vmasm_breakpoint - Set a breakpoint at a vmasm bytecode address

• address (number or string, required): Bytecode address - supports hex string (e.g., "0x0000", "0x100") or decimal (e.g., 0, 256)
• Note: Requires a vmasm file to be loaded first

list_vmasm_breakpoints - List all active vmasm breakpoints

• No parameters

remove_vmasm_breakpoint - Remove a vmasm breakpoint by its ID

• breakpointId (string, required): The breakpoint ID to remove (e.g., "vmasm-bp-1")

clear_vmasm_breakpoints - Remove all vmasm breakpoints

• No parameters

Console

list_console_messages - List console messages

• pageSize (number, optional): Maximum messages to return
• pageIdx (number, optional): Page number (0-based)
• types (array, optional): Filter by message types (e.g., ["log", "error", "warn"])
  • Available types: log, debug, info, error, warn, dir, dirxml, table, trace, clear, assert, issue, etc.
• includePreservedMessages (boolean, optional): Include messages from last 3 navigations (default: false)
• savePath (string, optional): Save messages to file instead of displaying
• maxLineLength (number, optional): Max characters per line (default: 500)

get_console_message - Get a specific console message by ID

• msgid (number, required): Message ID from list_console_messages

Script Evaluation

evaluate_script - Evaluate JavaScript code in the page context

• script (string, required): JavaScript code to execute
• maxOutputChars (number, optional): Maximum characters in the output (default: 10000)

Configuration Options

| Option | Description | Default | |--------|-------------|---------| | --cdp-url | CDP URL to connect to a running Chrome instance | http://127.0.0.1:9222 | | --browser-url | Connect to a debuggable Chrome instance | - | | --ws-endpoint | WebSocket endpoint for Chrome connection | - | | --headless | Run Chrome in headless mode | false | | --executable-path | Path to custom Chrome executable | - | | --viewport | Initial viewport size (e.g., 1280x720) | - | | --user-data-dir | Chrome user data directory | - | | --channel | Chrome channel (stable, beta, dev, canary) | stable | | --isolated | Use temporary user data directory | false | | --no-sandbox | Disable Chrome sandboxes (for Docker) | false | | --proxy-server | Proxy server configuration | - | | --proxy-username | Proxy authentication username | - | | --proxy-password | Proxy authentication password | - | | --log-file | Path to save debug logs | - | | --no-category-emulation | Disable emulation tools | - | | --no-category-network | Disable network tools | - |

Examples

Connect to an existing Chrome instance:

npx @reverse-craft/rc-devtools-mcp@latest --browser-url http://127.0.0.1:9222

Run in headless mode:

npx @reverse-craft/rc-devtools-mcp@latest --headless

Use Chrome Canary:

npx @reverse-craft/rc-devtools-mcp@latest --channel canary

Set viewport size:

npx @reverse-craft/rc-devtools-mcp@latest --viewport 1920x1080

Use with proxy:

npx @reverse-craft/rc-devtools-mcp@latest --proxy-server http://proxy.example.com:8080

Requirements

• Node.js 20.19.0+, 22.12.0+, or 23+
• Chrome/Chromium browser (automatically managed or custom installation)

License

Apache-2.0