MCP Defender

What is MCP Defender?

MCP Defender is a desktop app that protects AI apps like Cursor from attacks by automatically proxying all MCP tool call requests and responses, checking them against a set of signatures, and alerting you to allow or block any harmful activity.

How to use MCP Defender?

Download the latest release for Mac from the GitHub releases page, or clone the repo, install dependencies with npm install, and start the app with npm start.

Key features of MCP Defender

• Automatically proxies MCP tool call traffic from AI apps
• Checks intercepted data against attack signatures
• Alerts the user and asks to allow or block detected threats
• Protects Cursor, Claude, Visual Studio Code, and Windsurf

Use cases of MCP Defender

• Protect AI coding assistants from malicious tool call attacks
• Intercept and inspect MCP traffic for security vulnerabilities
• Block harmful actions before they execute in the AI app

FAQ from MCP Defender

Which apps are automatically protected?

MCP Defender protects Cursor, Claude, Visual Studio Code, and Windsurf.

How do I get started?

Download the latest release for Mac from the GitHub releases page, or clone the repo, then run npm install and npm start.

What license is MCP Defender under?

MCP Defender is licensed under the AGPL-3.0 license.

Who acquired MCP Defender?

MCP Defender has been acquired by Docker Inc.

What does MCP Defender protect against?

It protects against attacks on MCP tool calls by checking the intercepted data against a set of signatures and alerting you if anything harmful is detected.