MCP Guard: Open source MCP Guardrail for Cursor and Claude Code

3 months ago 1

An MCP (Model Context Protocol) guardrail with built-in AI-powered moderation that aggregates multiple MCP servers into one secure interface.

The MCP Guardrail provides AI-powered security and easy configuration for your MCP (Model Context Protocol) setup. It automatically detects your existing MCP configuration files and adds a protective layer with intelligent moderation capabilities.

Key features:

AI-powered moderation to prevent prompt injection attacks
Automatic configuration - CLI tool detects and updates MCP config files for Cursor, Claude Desktop, and Claude Code
Dual connectivity - supports both local and remote MCP servers
Transparent proxying - tools, prompts, and resources are automatically prefixed and made available

The easiest way to get started is using the General Analysis CLI tool:

# Install the CLI tool pip3 install generalanalysis # Login to your account ga login # Configure MCP settings for Cursor, Claude Desktop, and Claude Code ga configure

This will automatically update your MCP configuration files with the guardrail setup.

No installation required! Use directly in your Cursor or Claude Desktop MCP configuration:

{ "mcpServers": { "protected_server": { "command": "npx", "args": [ "-y", "@general-analysis/mcp-guard", "[{\"name\":\"server1\",\"command\":\"path/to/server\",\"args\":[\"arg1\"]}]" ] } } }

npx -y @general-analysis/mcp-guard '[{"name":"server1","command":"path/to/server","args":["arg1"]}]'

For local MCP servers that communicate via stdio:

{ "mcpServers": { "protected_server": { "command": "npx", "args": [ "-y", "@general-analysis/mcp-guard", "[{\"name\":\"my-local-server\",\"command\":\"node\",\"args\":[\"path/to/server.js\"]}]" ], "env": { "API_KEY": "your-general-analysis-api-key", "ENABLE_GUARD_API": "true" } } } }

Remote Servers (HTTP/SSE)

For remote MCP servers accessible via HTTP or Server-Sent Events:

{ "mcpServers": { "protected_server": { "command": "npx", "args": [ "-y", "@general-analysis/mcp-guard", "[{\"name\":\"my-remote-server\",\"url\":\"https://api.example.com/mcp\"}]" ], "env": { "API_KEY": "your-general-analysis-api-key", "ENABLE_GUARD_API": "true" } } } }

API_KEY - Your General Analysis API key for the moderation service
ENABLE_GUARD_API - Set to "true" to enable AI-powered moderation (requires API_KEY)

Complete Example for Cursor/Claude Desktop

Add this to your MCP configuration file:

{ "mcpServers": { "guardrail": { "command": "npx", "args": [ "-y", "@general-analysis/mcp-guard", "[{\"name\":\"local-filesystem\",\"command\":\"npx\",\"args\":[\"@modelcontextprotocol/server-filesystem\",\"/path/to/files\"]},{\"name\":\"remote-api\",\"url\":\"https://api.example.com/mcp\"}]" ], "env": { "API_KEY": "your-general-analysis-api-key", "ENABLE_GUARD_API": "true" } } } }

Standalone Command Line Example

# Set environment variables export API_KEY="your-general-analysis-api-key" export ENABLE_GUARD_API="true" # Run with mixed local and remote servers npx -y @general-analysis/mcp-guard '[ { "name": "local-filesystem", "command": "npx", "args": ["@modelcontextprotocol/server-filesystem", "/path/to/files"] }, { "name": "remote-api", "url": "https://api.example.com/mcp" } ]'