MCP server CodeQL Development

CodeQL Development MCP Server

Enabling AI-assisted CodeQL query development through the Model Context Protocol

A comprehensive Model Context Protocol (MCP) server designed specifically for agentic AI development of CodeQL (QL) code. This server provides tools, prompts, and resources to help AI assistants write, validate, and optimize CodeQL queries for security analysis and code quality.

Features

• Comprehensive Tool Suite - Wraps CodeQL CLI commands for query compilation, execution, testing, and database operations
• Multi-Language Support - Supports CodeQL query development for 10 languages including Python, JavaScript, Java, C/C++, Rust, Swift, and more
• AI-Optimized Prompts - Built-in prompts and resources that guide AI assistants through CodeQL development workflows
• Test-Driven Development - Integrated testing tools for validating query accuracy with expected results
• Flexible Transport - Supports both stdio and HTTP transport modes for different integration scenarios

Limitations

• Requires CodeQL CLI to be installed separately
• Performance depends on the size of CodeQL databases being analyzed
• Some advanced CodeQL CLI features may not yet be exposed as tools

Project Status

Active Development - This project is actively maintained and used in production environments for AI-assisted CodeQL development.

Background

The codeql-development-mcp-server project is maintained by GitHub's CodeQL Expert Services team and builds (and hopefully improves) on the concepts from the advanced-security/codeql-development-template repository template.

The main advantages of using the codeql-development-mcp-server are:

1. Agnostic of development environment
2. Agnostic of calling Large Language Model (LLM)
3. MCP server tools codify advanced CodeQL development practices

Roadmap

Development priorities and open issues are tracked in GitHub Issues.

Contributing

We welcome contributions! Whether it's bug fixes, new features, documentation improvements, or additional language support, please see CONTRIBUTING.md for guidelines.

Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.

Requirements

Environment

• Node.js v25.6.0 or later (nodejs.org)
• Some calling LLM Bring your own LLM, but some LLMs are (much) better than others.

External Dependencies

• CodeQL CLI - Must be installed and available in PATH (github.com/github/codeql-cli-binaries)

Quick Start

VS Code extension via VSIX (recommended for IDEs)

If you run ql-mcp inside VS Code or a compatible fork such as Cursor, install the vscode-codeql-development-mcp-server extension from a VSIX archive — it bundles the server, auto-registers ql-mcp, and discovers the CodeQL CLI. Download the .vsix from GitHub Releases and install it via Extensions: Install from VSIX… in the Command Palette, or build it from source with npm run package:vsix. See the VS Code Extension guide for details.

For Copilot CLI or other non-IDE agentic tools, use one of the methods below.

Install via npm

No repository clone needed — install from npmjs.org:

# Install globally
npm install -g codeql-development-mcp-server

Or run on-demand without installing globally:

npx -y codeql-development-mcp-server

VS Code Configuration

Add to your mcp.json file:

OS	Location
Linux	~/.config/Code/User/mcp.json
macOS	~/Library/Application Support/Code/User/mcp.json
Windows	%APPDATA%\Code\User\mcp.json

{
  "servers": {
    "ql-mcp": {
      "command": "npx",
      "args": ["-y", "codeql-development-mcp-server"],
      "type": "stdio"
    }
  }
}

Install from GitHub Release archive

1. Download the latest release from GitHub Releases
2. Extract the archive:

tar -xzf codeql-development-mcp-server-vX.X.X.tar.gz -C /path/to/destination

Installing from Source

git clone https://github.com/advanced-security/codeql-development-mcp-server.git
cd codeql-development-mcp-server
npm install && npm run build

Server + extension only (no Go client): npm run build also builds the Go client/ CLI (requires a Go toolchain). To build or package only the server and VS Code extension, use npm run build:server-and-extension or npm run package:vsix — neither touches client/.

Verification

1. Restart VS Code
2. Open Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
3. Run "GitHub Copilot: List MCP Servers"
4. Confirm ql-mcp appears

Supported Languages

Language	CodeQL Identifier
GitHub Actions	actions
C/C++	cpp
C#	csharp
Go	go
Java/Kotlin	java
JavaScript/TypeScript	javascript
Python	python
Ruby	ruby
Swift	swift

Documentation

• Public Installation Guide - Install and run without cloning the repository
• Getting Started Guide - Detailed installation and setup instructions
• Tools Reference - Complete list of available MCP tools
• Prompts Reference - MCP prompts for CodeQL development workflows
• Resources Reference - MCP resources for CodeQL learning and reference
• Testing Strategy - Multi-layer testing approach

License

This project is licensed under the terms of the GitHub CodeQL Terms and Conditions. Please refer to LICENSE for the full terms.

Maintainers

This repository is maintained by the team specified in CODEOWNERS.

Support

This project uses GitHub issues to track bugs and feature requests. Please search existing issues before filing new ones to avoid duplicates.

This project comes with no expectation or guarantee of support, with more details in the SUPPORT.md document.

Acknowledgement

This project builds upon the CodeQL CLI and the broader CodeQL ecosystem developed by GitHub. Special thanks to the GitHub Advanced Security team and the open-source community for their contributions.