Joern MCP Server

What is Joern MCP Server?

An MCP server based on Joern that provides features for code review and security analysis. It is designed for developers using large language models to analyze source code.

How to use Joern MCP Server?

Install dependencies with Python 3.10+ and uv, start the Joern server with the provided command, copy env_example.txt to .env, modify JVM and auth settings, then configure the server in your MCP client (e.g., Cline) using the sample sample_cline_mcp_settings.json. Finally, ask questions to the language model as described in prompts_en.md.

Key features of Joern MCP Server

• Code review and security analysis via Joern
• MCP‑based integration with LLMs
• Scala tools for server interaction
• Test clients to verify connectivity
• Environment variable configuration support

Use cases of Joern MCP Server

• Automated security auditing of codebases
• Assisting LLMs in static analysis queries
• Integrating Joern’s code property graphs into MCP‑aware tools

FAQ from Joern MCP Server

What is Joern MCP Server?

A simple MCP Server for Joern that helps developers with code review and security analysis.

What are the environment requirements?

Python >= 3.10 (default 3.12), the uv package manager, and a running Joern instance.

How do I install it?

Clone the repository, create a virtual environment with uv venv .venv, activate it, and run uv sync.

How do I configure authentication?

The Joern server must be started with --server-auth-username and --server-auth-password flags; these values are then set in the .env file.

How can I contribute?

Submit Issues and Pull Requests to improve the project or add new tools.