Jadx Mcp Plugin

What is Jadx Mcp Plugin

jadx-mcp-plugin is a Java-based plugin for Jadx that exposes the Jadx API over HTTP, allowing live interaction with Claude through the Model Context Protocol (MCP).

Use cases

Use cases include analyzing Java bytecode, debugging applications, and enhancing the functionality of Claude with decompilation capabilities.

How to use

To use jadx-mcp-plugin, clone the repository, set up a Python virtual environment, install the required dependencies, and configure Claude to point to the MCP server using the provided settings.

Key features

Key features include live interaction with the Jadx API, compatibility with Claude, and a lightweight FastMCP adapter in Python that facilitates communication.

Where to use

jadx-mcp-plugin is primarily used in software development, reverse engineering, and security analysis, particularly for decompiling Java applications.

⚙️ Jadx MCP Plugin — Decompiler Access for Claude via MCP

This project provides a Jadx plugin written in Java, which exposes the Jadx API over HTTP — enabling live interaction through MCP clients like Claude via the Model Context Protocol (MCP). A lightweight FastMCP adapter in Python acts as a bridge between Claude and the plugin. This enables intelligent navigation and automation of reverse engineering workflows, ideal for AI-assisted security analysis of Android apps.

🧰 Setup Instructions

# Clone this repository
git clone https://github.com/mobilehackinglab/jadx-mcp-plugin.git
cd jadx-mcp-plugin

# Create and activate a virtual environment
python3 -m venv venv

# Activate:
source venv/bin/activate      # Linux/Mac
.\venv\Scripts\activate       # Windows

Install Python dependencies

pip install -r requirements.txt 

🧠 Setup Claude MCP CLient Integration

To use this adapter in Claude Desktop, go to File -> Settings -> Developer -> Edit Config -> claude_desktop_config.json and add an MCP server pointing to the Python executable in the venv (to prevent depedency issues) and the full adapter path following below examples:

Windows:

{
  "mcpServers": {
    "Jadx MCP Server": {
      "command": "C:\\Workset\\jadx-mcp-plugin\\venv\\Scripts\\python.exe",
      "args": [
        "C:\\Workset\\jadx-mcp-plugin\\fastmcp_adapter.py"
      ]
    }
  }
}

MacOS / Linux:

{
  "mcpServers": {
    "Jadx MCP Server": {
      "command": "/Users/yourname/jadx-mcp-plugin/venv/bin/python",
      "args": [
        "/Users/yourname/jadx-mcp-plugin/fastmcp_adapter.py"
      ]
    }
  }
}

Make sure to restart (Quit) Claude after editing the config.
After restart it should look like this:

✅ Usage Flow

1. Open Jadx with the latest plugin JAR from the releases placed in its plugins/ folder or load it via Plugins -> install plugin.

2. Load an APK or DEX file

3. (Optional) You can specify the HTTP interface address by launching Jadx with:

   jadx-gui -Pjadx-mcp.http-interface=http://localhost:8085
   

   This is useful if you want to change the default host/port (http://localhost:8085).

   Note: If you change the interface address here, make sure to also update the corresponding URL in fastmcp_adapter.py to match.

4. Claude will detect and activate the Jadx MCP Server tools.

5. You can now list classes, fetch source, inspect methods/fields, and extract code live.

🧪 Tools Provided

🛠 Development

☕ Java Plugin

The Java plugin is located at:

plugin/src/main/java/com/mobilehackinglab/jadxplugin/McpPlugin.java

It uses the JadxPlugin API (jadx.api.*) to:

• Load decompiled classes and methods
• Serve structured data via an embedded HTTP server
• Respond to /invoke and /tools endpoints

🚀 Automated Installation with Gradle Tasks

You can use the following Gradle task to build and install the plugin in one step:

./gradlew installPlugin

This uses the jadx plugins CLI. Make sure Jadx is installed and available in your PATH.

For other plugin-related tasks (uninstall, enable/disable), see the task definitions in plugin/build.gradle.

🔧 Manual Installation

To build the plugin:

./gradlew build
# Output: plugin/build/libs/jadx-mcp-plugin-<version>.jar

Install the plugin JAR using the jadx plugins CLI:

jadx plugins --install-jar path/to/jadx-mcp-plugin-<version>.jar

Alternatively, place the built .jar file into your Jadx plugins/ folder, typically located at: ~/.jadx/plugins/

If you place the JAR manually, you’ll also need to enable the plugin through the Jadx GUI or by running:

jadx plugins --enable jadx-mcp

Python FastMCP Adapter

The adapter file is:

fastmcp_adapter.py

It translates Claude’s MCP tool calls into HTTP POSTs to the running Jadx plugin server. Make sure Jadx is open before starting Claude.

🤝 Contributing

PRs, feature requests, and tool extensions are welcome!
This project is maintained by Mobile Hacking Lab.

🧩 Credits

• Jadx
• FastMCP
• Claude by Anthropic