ActionGuard Protocol Inspector Agent MCP server

ActionGuard.ai

Drift and poisoning detection for MCP servers.

"SSL Labs for MCP servers. Know when your tools change, not just when they go down."

Diff detection for MCP tools: catch silent schema drift and poisoned tool descriptions before your autonomous agents run them.

Live Production Services

• 🌐 Web Inspector & Diagnostic Engine: https://actionguard.ai/
• 📊 Public Reliability Index: https://actionguard.ai/index
• 🎮 Interactive Drift & Prompt Poisoning Simulator: https://actionguard.ai/playground
• ⭐ Self-Serve Domain Ownership Portal: https://actionguard.ai/verify
• 💳 Developer API Keys & Pricing: https://actionguard.ai/pricing
• 📖 Protocol Guides & Specs: https://actionguard.ai/docs/mcp-schema-drift

Quickstart

1. GitHub Actions CI Gate

Block breaking changes and unannounced schema mutations before they hit production:

name: CI
on: [pull_request]

jobs:
  verify-agent-tools:
    runs-on: ubuntu-latest
    steps:
      - name: Verify Upstream MCP Tools
        uses: lsendel/actionguard@v1
        with:
          target_url: 'https://github.mcp.modelcontextprotocol.io/mcp'
          pinned_hash: '81d36f5215b689d6f100cfe77096fbe8d113c304c0dd8374d69a84678fb69415'

2. Zero-Trust Runtime Gateway Proxy ("Cloudflare for MCP")

Route agent tool calls through ActionGuard's edge firewall to terminate drifted tools with HTTP 423 Locked:

Claude Desktop & Cursor (claudedesktopconfig.json)

{
  "mcpServers": {
    "github": {
      "url": "https://actionguard.ai/v1/proxy?target=https://github.mcp.modelcontextprotocol.io/mcp&pin=81d36f5215b689d6f100cfe77096fbe8d113c304c0dd8374d69a84678fb69415"
    }
  }
}

Python (LangChain / CrewAI / httpx)

import httpx

GATEWAY = "https://actionguard.ai/v1/proxy"
TARGET = "https://github.mcp.modelcontextprotocol.io/mcp"
PIN = "81d36f5215b689d6f100cfe77096fbe8d113c304c0dd8374d69a84678fb69415"

# Requests fail with 423 Locked if upstream schema drifts or tool is poisoned
client = httpx.Client(base_url=f"{GATEWAY}?target={TARGET}&pin={PIN}")

3. Run as an MCP Server (Claude Desktop, Cursor, Glama)

You can run ActionGuard natively as a tool inside any MCP client:

Stdio Mode (Claude Desktop claudedesktopconfig.json)

{
  "mcpServers": {
    "actionguard": {
      "command": "npx",
      "args": ["-y", "@actionguard/cli", "mcp"]
    }
  }
}

Streamable HTTP Mode

{
  "mcpServers": {
    "actionguard": {
      "url": "https://actionguard.ai/mcp"
    }
  }
}

4. CLI Quick Run

# Run 5-stage live protocol audit against any MCP or A2A endpoint
npx @actionguard/cli inspect https://api.myservice.com/mcp

# Compile single actionguard.json to MCP server.json, A2A agent-card.json, and DNS-AID records
npx @actionguard/cli compile ./actionguard.json

# Local CI check
npx @actionguard/cli check https://api.myservice.com/mcp --pin <hash>

Shortened. The full README is on GitHub.