ActionGuard Protocol Inspector Agent

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 (claude_desktop_config.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 claude_desktop_config.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>

Core Product Pillars

1. The 5-Stage Live Inspector ("SSL Labs for Agents"): Zero-signup diagnostic tool running live edge probes against MCP and A2A endpoints, returning an A+ to F scorecard and instant copy-paste fixes.
2. Dual-Hash Integrity Engine: Distinct cryptographic fingerprints for JSON Schemas (schema_sha256) versus tool descriptions (descriptions_sha256) to catch silent prompt mutations.
3. Enterprise Dependency Watchlist: Automated 15-minute edge monitoring with instant multi-channel alerts (Slack Block Kit, Discord Embeds, Email via Resend, and signed Webhooks).
4. Self-Serve Domain Proof (DNS-AID): Cryptographic domain verification via DNS TXT records or well-known challenge files to earn the Gold "⭐ Domain Verified" badge.
5. Zero-Trust Runtime Firewall: Low-latency proxy (<15ms) that blocks execution before poisoned or drifted payloads reach your LLM.

Infrastructure Architecture

Built entirely on the Cloudflare edge stack for global sub-50ms latency:

• Cloudflare Workers: Edge probing engine, public API, zero-trust proxy, and dynamic SVG badges.
• Cloudflare D1: High-performance relational edge database for accounts, catalog, subscriptions, and API keys.
• Cloudflare R2: Content-addressed, immutable storage for historical snapshot payloads, raw schemas, and audit logs.
• Continuous Monitoring: 15-minute cron trigger with automatic drift detection and Resend email / Slack dispatch.

Monorepo Packages

├── packages/
│   ├── core/         # @actionguard/core — Dual-hash, linter, compiler, and probes
│   └── cli/          # @actionguard/cli — actionguard command line tool
└── apps/
    └── worker/       # Cloudflare Worker — Web Inspector, API, proxy, and D1/R2 storage

Documentation

• Product Requirements Document (PRD)
• Protocol Specifications & Mappings
• System Architecture & Data Model
• Step-by-Step Implementation Plan
• Hacker News Show HN Submission
• Product Hunt & Twitter Launch Kit

License

MIT © ActionGuard.ai