README

From the repo.

Shows a black knight in light color mode and a white knight one in dark color mode.

MCP Defender

Automatically protects MCP traffic in AI apps

🛡️ MCP Defender is a desktop app that protects AI apps like Cursor from a variety of attacks.

🚦 All MCP tool call requests and responses from AI apps are automatically proxied through MCP Defender.

🔎 The intercepted data is then checked against a set of signatures.

🔐 If anything harmful is detected, MCP Defender alerts you and asks if you want to allow or block the tool call.

Alternatively you can clone the git repo, and run it as follows:

# Install dependencies
npm install

# Start app
npm start

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

MCP Defender is licensed under the AGPL-3.0 license. For more details, see the LICENSE.

Config for your environment

Replace {MCP_ENDPOINT_URL} with this MCP’s endpoint URL (from its repo or docs above). No API key — you connect directly.

Tool

Config file: ~/.cursor/mcp.json

{
  "mcpServers": {
    "mcp-server": {
      "url": "{MCP_ENDPOINT_URL}"
    }
  }
}

Paste into mcpServers in the config file. Restart Cursor after saving.