KindlyGuard

Security-focused MCP (Model Context Protocol) server that protects AI systems against unicode attacks, injection threats, and other vulnerabilities.

Features

• Unicode Attack Detection: Identifies hidden characters, BiDi overrides, and homograph attacks
• Injection Protection: Detects SQL, command, and code injection attempts
• Real-time Monitoring: Live threat detection and statistics
• MCP Integration: Works seamlessly with Claude Desktop and other MCP clients
• Cross-platform: Supports Linux, macOS (Intel & Apple Silicon), and Windows

Installation

npm install -g @kindlyguard/kindlyguard

Or use directly with npx (no installation required):

npx @kindlyguard/kindlyguard --stdio

Quick Start

As an MCP Server with Claude Desktop

1. Add to your Claude Desktop configuration:
   • macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
   • Windows: %APPDATA%\Claude\claude_desktop_config.json
   • Linux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "kindlyguard": {
      "command": "npx",
      "args": ["@kindlyguard/kindlyguard", "--stdio"],
      "env": {
        "RUST_LOG": "info"
      }
    }
  }
}

2. Restart Claude Desktop
3. KindlyGuard will automatically protect your AI interactions

As an MCP Server with VS Code

Add to your VS Code settings:

{
  "mcp.servers": {
    "kindlyguard": {
      "command": "npx",
      "args": ["@kindlyguard/kindlyguard", "--stdio"],
      "env": {
        "RUST_LOG": "debug"
      }
    }
  }
}

Command Line Interface

# Start as MCP server (for Claude Desktop integration)
npx @kindlyguard/kindlyguard --stdio

# Scan a file for threats
npx @kindlyguard/kindlyguard scan suspicious.txt

# Scan text directly
npx @kindlyguard/kindlyguard scan "Hello\u202Eworld"

# Get JSON output
npx @kindlyguard/kindlyguard scan --format json data.json

# Check server status
npx @kindlyguard/kindlyguard status

# View help
npx @kindlyguard/kindlyguard --help

Programmatic API

const kindlyguard = require('@kindlyguard/kindlyguard');

// Example 1: Start MCP server
const server = kindlyguard.create({ stdio: true });
const mcp = server.start();

// Send MCP messages
mcp.send({
  jsonrpc: "2.0",
  method: "initialize",
  params: { protocolVersion: "0.1.0" },
  id: 1
});

// Handle responses
mcp.onMessage((message) => {
  console.log('Received:', message);
});

// Example 2: Quick threat scanning
const threats = await kindlyguard.scan('Hello\u202Eworld', {
  format: 'json'
});
console.log('Threats found:', threats);

// Example 3: Custom server with events
const customServer = kindlyguard.create({
  stdio: false,
  shield: true,
  onError: (error) => console.error('Server error:', error),
  onExit: (code) => console.log(`Server exited: ${code}`)
});

Configuration

KindlyGuard can be configured using a TOML file. Pass the config path with --config:

npx @kindlyguard/kindlyguard --stdio --config ./my-config.toml

Example kindly-guard.toml:

[server]
host = "127.0.0.1"
port = 3000

[security]
unicode_checks = true
injection_checks = true
max_input_size = "10MB"
rate_limit = 100  # requests per minute

[shield]
enabled = true
update_interval = "1s"

[resilience]
enhanced_mode = false  # Enable advanced resilience features

Platform Support

KindlyGuard provides pre-built binaries for:

• Linux x64
• macOS x64 (Intel)
• macOS arm64 (Apple Silicon)
• Windows x64

The correct binary is automatically installed based on your platform.

Examples

See the examples/ directory for more usage examples:

• claude_desktop_config.json - Claude Desktop configuration
• vscode_mcp_config.json - VS Code MCP configuration
• nodejs_usage.js - Node.js integration examples

Troubleshooting

KindlyGuard not starting

1. Check if the binary is installed:

   npx @kindlyguard/kindlyguard status

2. Enable debug logging:

   RUST_LOG=debug npx @kindlyguard/kindlyguard --stdio

3. Verify your configuration file syntax

Claude Desktop not detecting KindlyGuard

1. Ensure the config file is in the correct location
2. Restart Claude Desktop after configuration changes
3. Check Claude Desktop logs for errors

Building from Source

If you need to build from source:

git clone https://github.com/samduchaine/kindly-guard
cd kindly-guard
cargo build --release

Security Features

Unicode Attack Detection

• Invisible characters (U+200B, U+200C, U+200D)
• Right-to-Left overrides (U+202E)
• Homograph attacks using similar-looking characters
• Zero-width characters and joiners
• Bidirectional text manipulation

Injection Prevention

• SQL injection patterns
• Command injection (shell commands)
• Code injection (JavaScript, Python)
• Path traversal attempts
• LDAP injection
• XSS patterns

Protection Mechanisms

• Real-time threat scanning
• Rate limiting and DoS prevention
• Request size limits
• Pattern-based detection
• Context-aware analysis

Performance

KindlyGuard is built with Rust for maximum performance:

• Near-zero overhead threat detection
• Lock-free statistics collection
• SIMD-optimized pattern matching
• Minimal memory footprint (<10MB)
• Sub-millisecond response times

License

Apache-2.0

Links

• GitHub Repository
• Documentation
• Issues
• NPM Package