Check any IP address for fraud signals — VPN, proxy, Tor, datacenter hosting, anonymity — straight from Claude, Cursor, or any MCP client. Powered by the Maskbreak fraud detection API.

Tools

Tool	What it does
`lookup_ip`	Verdict for any public IPv4/IPv6: `allow` / `review` / `block`, 0–100 risk score, VPN/proxy/Tor/datacenter/anonymity signals, ASN + org + country
`service_status`	Maskbreak API health, uptime, and latency

Setup

Grab a free API key at maskbreak.com/signup (1,000 lookups/hour, no card). The server also works without a key for a few lookups per minute — enough to try it.

Claude Code

claude mcp add sentinel -e SENTINEL_API_KEY=sk_live_your_key -- npx -y @sentinelsup/mcp

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "sentinel": {
      "command": "npx",
      "args": ["-y", "@sentinelsup/mcp"],
      "env": { "SENTINEL_API_KEY": "sk_live_your_key" }
    }
  }
}

Cursor / other MCP clients

Any client that speaks stdio MCP works the same way: command npx, args ["-y", "@sentinelsup/mcp"], env SENTINEL_API_KEY.

Hosted endpoint (no install)

Prefer a remote server? The same tools are hosted at https://maskbreak.com/mcp (Streamable HTTP). Point any URL-based MCP client at it; pass your API key as an Authorization: Bearer header for full quota.

Example

"Is 185.220.101.34 safe to allow through signup?"

{
  "ip": "185.220.101.34",
  "known": true,
  "verdict": "block",
  "risk_score": 90,
  "signals": { "vpn": false, "proxied": false, "tor": true, "dch": true, "anon": true },
  "network": { "asn": 205100, "org": "F3 Netze e.V.", "country": "DE" }
}

Environment

Variable	Required	Default	Purpose
`SENTINEL_API_KEY`	recommended	—	API key from your dashboard; unlocks 1,000 lookups/hour
`SENTINEL_BASE_URL`	no	`https://maskbreak.com`	Override for testing