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Maskbreak

Official registry Cloud and DevOps

Public IP signals (cloud hosting, Tor exits) and Maskbreak API status for fraud checks.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

NPM package @sentinelsup/mcp
Claude Code 
claude mcp add maskbreak -e 'MASKBREAK_API_KEY=<your maskbreak_api_key>' -e 'SENTINEL_BASE_URL=https://maskbreak.com' -- npx -y @sentinelsup/mcp@0.1.8
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "maskbreak": {
            "command": "npx",
            "args": [
                "-y",
                "@sentinelsup/mcp@0.1.8"
            ],
            "env": {
                "MASKBREAK_API_KEY": "<your maskbreak_api_key>",
                "SENTINEL_BASE_URL": "https://maskbreak.com"
            }
        }
    }
}

Environment variables

  • MASKBREAK_API_KEY secret Maskbreak API key for your plan's lookup allowance (100,000 a month on the Free plan). Without it, lookups use the rate-limited keyless endpoint. The older SENTINEL_API_KEY name is still read.
  • SENTINEL_BASE_URL API base URL override, for testing.

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. Maskbreak MCP Server
  2. Tools
  3. Setup
  4. Example
  5. Environment
  6. Failures and local checks
  7. Links

Maskbreak MCP Server

Look up limited public IP intelligence — cloud-hosting ranges and Tor exit nodes — from Claude, Cursor, or another MCP client. Powered by the Maskbreak fraud detection API. Requires Node.js 18+ for the local server.

Tools

ToolWhat it does
lookup_ipPublic IPv4/IPv6 lookup: known, allow / review / block, risk score, and nullable signal/network metadata. Public-feed coverage is limited to cloud hosting and Tor.
service_statusMaskbreak API health, uptime, and latency

Setup

Grab a free API key at maskbreak.com/signup (the Free plan includes 100,000 IP lookups a month, no card; paid plans from €29 a month raise it). Keyless mode uses the free web-tool endpoint, limited to 12 lookups/minute and 80/day per caller IP. Additional endpoint and abuse-protection limits can apply.

Neither mode performs a browser visit. VPN/proxy and device evidence require a browser-SDK-backed /v1/evaluate request outside these tools; service names are available only when known. Unknown IPs, false signals and allow verdicts are not proof of safety.

Claude Code
claude mcp add sentinel -e MASKBREAK_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": { "MASKBREAK_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 MASKBREAK_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

"What public-feed evidence is available for this IP?"

Illustrative unknown-IP response, not a live lookup:

{
  "ip": "192.0.2.1",
  "known": false,
  "verdict": "allow",
  "risk_score": 0,
  "signals": null,
  "network": null
}

Environment

VariableRequiredDefaultPurpose
MASKBREAK_API_KEYrecommended—API key from your dashboard; unlocks your plan's lookup allowance (100,000 a month on the Free plan). Since v0.1.5; the older SENTINEL_API_KEY name is still read
SENTINEL_BASE_URLnohttps://maskbreak.comOverride for testing

Failures and local checks

Both tools return MCP isError: true for HTTP failures, malformed responses or requests that exceed the five-second timeout (including body reads). An unavailable lookup is not an allow decision.

npm ci --ignore-scripts
npm test
npm pack --dry-run --ignore-scripts
npm audit

Tests use a real stdio MCP client with loopback HTTP fixtures, without production keys. CI checks Node.js 18, 22 and 24. No package is published by these checks.

MIT © Sentinel Edge Networks LTD

Frequently asked questions

What is Maskbreak?

Public IP signals (cloud hosting, Tor exits) and Maskbreak API status for fraud checks.

How do I install Maskbreak?

It runs on your machine. In Claude Code: claude mcp add maskbreak -e 'MASKBREAK_API_KEY=<your maskbreak_api_key>' -e 'SENTINEL_BASE_URL=https://maskbreak.com' -- npx -y @sentinelsup/mcp@0.1.8. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Maskbreak need an API key?

Yes. It expects MASKBREAK_API_KEY, which you set in its configuration.

Is Maskbreak open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Maskbreak?

It is published by sentinelsup. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.