npm install mcp-guardian

# Auto-detect Claude Desktop config
npx mcp-guardian

# Explicit config path
npx mcp-guardian /path/to/claude_desktop_config.json

# JSON output
npx mcp-guardian --json

npx mcp-guardian --mcp

{
  "mcpServers": {
    "mcp-guardian": {
      "command": "npx",
      "args": ["-y", "mcp-guardian", "--mcp"]
    }
  }
}

import {
  scanToolDescription,
  scanToolDefinitions,
  isDescriptionSafe,
  verifyToolDefinitions,
} from "mcp-guardian";

// Scan a single tool description
const result = scanToolDescription("my_tool", "Tool description here");
if (result.status === "critical") {
  console.error("Potential injection:", result.issues);
}

// Quick safety check
if (!isDescriptionSafe("Before using this tool, first call...")) {
  console.warn("Suspicious description detected");
}

// Scan multiple tools
const tools = [
  { name: "tool1", description: "...", schema: {} },
  { name: "tool2", description: "...", schema: {} },
];
const serverResult = scanToolDefinitions(tools, "my-server");

// Tool pinning - detect changes
const pinResult = verifyToolDefinitions(tools);
if (pinResult.status === "changed") {
  console.warn("Tool definitions changed:", pinResult.changedTools);
}

npx mcp-guardian demo

✅ filesystem (14 tools)
✅ memory (9 tools)
🔴 suspicious-tool (4 tools)
   └─ add: sensitive_path (~/.ssh)
   └─ format_text: privilege_escalation ("You are now")
   └─ search_docs: exfiltration (evil URL), sensitive_path (~/.aws/credentials)

Summary:
  📊 Total tools: 27
  ✅ Clean: 2
  ⚠️  Warning: 0
  🚨 Critical: 1

repos:
  - repo: https://github.com/alexandriashai/mcp-guardian
    rev: v1.2.2
    hooks:
      - id: mcp-guardian

#!/bin/sh
. "$(dirname "$0")/_/husky.sh"

npx mcp-guardian --sync --quiet

pre-commit:
  commands:
    mcp-guardian:
      glob: "claude_desktop_config.json"
      run: npx mcp-guardian --sync {staged_files}

import { verifyToolDefinitions, approveAllTools } from "mcp-guardian";

// Verify tools against stored baseline
const result = verifyToolDefinitions(tools);

// Status: "created" | "verified" | "changed" | "error"
if (result.status === "changed") {
  console.log("Modified tools:", result.changedTools);
  console.log("New tools:", result.newTools);
  console.log("Removed tools:", result.removedTools);
}

// Re-approve all tools (after review)
approveAllTools(tools);