🔒 mcpguard-cli

The 1Password for AI Agents — Secure MCP credential manager

mcpguard replaces plaintext API keys in your MCP config files with encrypted vault references. Credentials are stored securely in your OS keychain — never written to disk in plaintext.

⚠️ The Problem

53% of MCP servers use plaintext API keys stored in config files. These keys get:

• Committed to git repositories
• Shared across machines
• Exposed in data breaches

8,000+ MCP servers were found publicly accessible on the internet in February 2026.

✅ The Solution

mcpguard is a local-first CLI tool that:

• Scans your MCP configs for plaintext credentials
• Migrates them to an encrypted vault (OS keychain)
• Replaces values with secure references
• Injects credentials at runtime — never on disk

🚀 Quick Start

# Install
npm install -g mcpguard-cli

# Audit your current setup
mcpguard audit

# Migrate all plaintext keys to vault
mcpguard migrate

# Done! Your credentials are now secure

📋 Commands

mcpguard audit

Scan MCP config files for plaintext credentials.

mcpguard audit
mcpguard audit --json
mcpguard audit --path ~/.config/claude/claude_desktop_config.json

Example output:

⚠️  SECURITY ALERT

3 of your 4 MCP servers have plaintext API keys

📁 Claude Desktop: ~/.config/claude/claude_desktop_config.json

  🔴 github.API_KEY
     Risk: CRITICAL
     Value: ghp_...x7k9

  🟠 linear.TOKEN
     Risk: HIGH
     Value: lin_...a2b4

📋 Recommended Actions:

  1. Run mcpguard migrate to move all keys to secure vault
  2. Rotate exposed API keys immediately
  3. Check git history for accidentally committed secrets

mcpguard migrate

Move all plaintext credentials to the secure vault.

mcpguard migrate
mcpguard migrate --yes  # Skip confirmation

What happens:

1. Scans all MCP config files
2. Identifies plaintext credentials
3. Stores each in OS keychain (encrypted)
4. Replaces values with mcpguard:// references
5. Your config files no longer contain secrets

mcpguard add <service>

Add a credential manually.

mcpguard add github
mcpguard add linear --key API_TOKEN
mcpguard add notion --value ntn_1234567890abcdef

mcpguard list

List all stored credentials.

mcpguard list
mcpguard list --json

mcpguard status

Show vault health and statistics.

mcpguard status

🔧 Supported Config Files

mcpguard automatically scans these locations:

| Config | Path | |--------|------| | Claude Desktop | ~/.config/claude/claude_desktop_config.json | | Claude Desktop (macOS) | ~/Library/Application Support/Claude/claude_desktop_config.json | | Cursor | ~/.cursor/mcp.json | | Generic | ~/.mcp.json, ./.mcp.json, ./mcp.json |

🛡️ Security Model

• OS Keychain: Credentials stored in macOS Keychain, Linux Secret Service, or Windows Credential Manager
• AES-256: Fallback encryption for credentials not in keychain
• Zero Plaintext: No secrets written to disk
• Local-First: No cloud sync, no network calls
• Open Source: Security through transparency

📦 Installation

npm

npm install -g mcpguard-cli

Homebrew (macOS/Linux)

Coming soon — Homebrew formula will be available in a future release.

From Source

git clone https://github.com/JulienPoitou/mcpguard
cd mcpguard
npm install
npm run build
npm link

🧪 Example Workflow

Before mcpguard

Your claude_desktop_config.json:

{
  "mcpServers": {
    "github": {
      "command": "mcp-server-github",
      "env": {
        "GITHUB_TOKEN": "ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      }
    },
    "linear": {
      "command": "mcp-server-linear",
      "env": {
        "LINEAR_API_KEY": "lin_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      }
    }
  }
}

⚠️ Problem: API keys are in plaintext, exposed to anyone with file access.

After mcpguard migrate

mcpguard migrate

Your config becomes:

{
  "mcpServers": {
    "github": {
      "command": "mcp-server-github",
      "env": {
        "GITHUB_TOKEN": "mcpguard://a1b2c3d4-e5f6-7890-abcd-ef1234567890"
      }
    },
    "linear": {
      "command": "mcp-server-linear",
      "env": {
        "LINEAR_API_KEY": "mcpguard://b2c3d4e5-f6a7-8901-bcde-f12345678901"
      }
    }
  }
}

✅ Secure: Credentials stored encrypted in OS keychain, injected at runtime.

🧩 Runtime Integration

mcpguard provides a runtime shim for MCP clients:

# Run your MCP client through mcpguard
mcpguard run claude

Or use the Node.js API:

import { McpGuardRuntime } from 'mcpguard/runtime';

const runtime = new McpGuardRuntime();
const config = await runtime.injectCredentials(originalConfig);

📊 Comparison

| Feature | mcpguard | Plaintext | 1Password | |---------|----------|-----------|-----------| | MCP-native | ✅ | ❌ | ❌ | | OS Keychain | ✅ | ❌ | ✅ | | Auto-migrate | ✅ | N/A | ❌ | | Local-first | ✅ | ✅ | ❌ | | Free | ✅ | ✅ | ❌ | | OAuth flows | ✅ (v0.2) | ❌ | ❌ |

🗺️ Roadmap

• v0.1 (Current): Vault + audit + migrate + basic CLI
• v0.2: OAuth flows for GitHub, Google, Linear, Notion; rotation alerts; audit log
• v0.3: mcpscan integration; permission scoping; provider registry
• v1.0: Team vaults; CI/CD integration; VSCode extension

🧠 Why "mcpguard"?

The Model Context Protocol (MCP) has become the universal interface between AI agents and tools. Adopted by Anthropic, OpenAI, Google, and backed by the Linux Foundation, MCP now powers integrations for GitHub, Linear, Figma, Supabase, Notion, and hundreds more.

mcpguard ensures this ecosystem doesn't repeat the mistakes of the past — plaintext credentials are not a viable security model.

📄 License

MIT — See LICENSE for details.

🤝 Contributing

Contributions welcome! Please read CONTRIBUTING.md first.

# Fork and clone
git clone https://github.com/YOUR_USERNAME/mcpguard
cd mcpguard

# Install dependencies
npm install

# Run tests
npm test

# Build
npm run build

📬 Issues

Report bugs and feature requests at github.com/JulienPoitou/mcpguard/issues.

Built with ❤️ by Julien Poitou