sentinel-hedera-mcp

AI-powered security gateway for autonomous AI agent payments on Hedera. Drop-in MCP server that replaces raw private keys with AI evaluation, AWS KMS signing, and immutable HCS audit trails.

The Problem

AI agents using x402 or direct payments hold private keys in plaintext:

{
  "mcpServers": {
    "wallet": {
      "env": { "WALLET_PRIVATE_KEY": "0xDANGEROUS..." }
    }
  }
}

One jailbreak, one env leak — wallet drained.

The Fix

Replace the private key with a Sentinel API key:

{
  "mcpServers": {
    "sentinel": {
      "command": "npx",
      "args": ["-y", "sentinel-hedera-mcp"],
      "env": {
        "SENTINEL_AGENT_ID": "agent-a1b2c3d4e5f6",
        "SENTINEL_API_KEY": "sntl_abc123...",
        "SENTINEL_GATEWAY_URL": "https://your-sentinel-backend.com"
      }
    }
  }
}

No private key anywhere. All signing happens via AWS KMS on the Sentinel backend.

Tools

| Tool | Description | |------|-------------| | paid_request | Make HTTP requests with automatic x402 payment handling | | transfer_hbar | Transfer HBAR with AI risk evaluation | | check_balance | Check agent balance, trust score, daily spending | | transaction_history | View recent transactions with AI evaluation results | | list_paid_apis | Discover available x402 paid API endpoints | | flag_transaction | Report incorrect/suspicious API data |

How It Works

1. Agent calls a tool (e.g., paid_request)
2. MCP server routes the request to Sentinel backend
3. Backend evaluates via 3-layer system: Rule Engine → AI (GPT-4o-mini) → Smart Contract
4. If approved: AWS KMS signs the transaction, submits to Hedera
5. If rejected: blocked, no funds move
6. Every decision logged immutably on Hedera Consensus Service

Environment Variables

| Variable | Required | Description | |----------|----------|-------------| | SENTINEL_AGENT_ID | Yes | Your agent ID (from Sentinel Dashboard registration) | | SENTINEL_API_KEY | Yes | Your agent API key (shown once at registration) | | SENTINEL_GATEWAY_URL | No | Sentinel backend URL (default: http://localhost:3001) |

Requirements

• Node.js >= 18
• A running Sentinel backend (github.com/ambesh333/Sentinel)
• A registered agent (via Sentinel Dashboard)

License

MIT