Checker MCP server

@oksigenia/checker-mcp

A domain security and privacy checker exposed as an MCP server. It runs entirely on your machine, makes no telemetry calls, and resolves DNS through Cloudflare DoH instead of Google.

Ask any MCP client to scan a domain and get back a scored report covering the certificate, email authentication, DNS and infrastructure, and web security headers, with a plain remediation for anything that fails.

Why it's different

• Local-first. The server runs over stdio and does its own DNS-over-HTTPS, HTTP, RDAP and TLS lookups. The only network traffic is the checks themselves.
• Zero telemetry. No analytics, no phone-home, no third-party scoring service in the loop.
• Privacy by default. DNS goes to Cloudflare DoH rather than Google, and the reputation check uses Cloudflare's malware/phishing resolver.
• Free software. Licensed GPL-3.0-or-later. Read it, run it, change it, self-host it.

Tools

The server exposes three tools.

check_domain

Scan a domain or URL and return a scored report from real live checks.

// arguments
{
  "domain": "example.com",          // bare domain or full URL
  "categories": ["ssl", "email"],   // optional subset; defaults to all
  "format": "report",               // "report" (default) or "json"
  "lang": "en"                      // "es" or "en"
}

list_checks

List every check grouped by category, with the reason each one matters.

{ "lang": "en" }

explain_check

Explain a single check by id, why it matters, and how to remediate a failure.

{ "check_id": "dmarc", "lang": "en" }

Checks

Seventeen checks across four categories, weighted to a 0-100 score.

Run listchecks for the full descriptions, or explaincheck for one at a time.

Install

Run it straight from npm with npx:

npx @oksigenia/checker-mcp

Register it with Claude Code:

claude mcp add oksigenia-checker -- npx -y @oksigenia/checker-mcp

Or add it to any MCP client config (works in Claude Desktop, Claude Code, or any MCP client):

{
  "mcpServers": {
    "oksigenia-checker": {
      "command": "npx",
      "args": ["-y", "@oksigenia/checker-mcp"],
      "env": { "OKSIGENIA_LANG": "en" }
    }
  }
}

Then ask: "Check the security of example.com" or "Explain the dmarc check."

Run with Docker

Build and run it as a container. It speaks MCP over stdio, so run it attached to your client's stdin/stdout (-i), not on a port.

docker build -t oksigenia-checker-mcp .
docker run --rm -i oksigenia-checker-mcp

Languages

Reports render in Spanish and English. Set the default with OKSIGENIA_LANG (es or en), or pass lang on any tool call. It defaults to English.

Privacy

The only thing that leaves your machine is the domain name you scan, sent to:

Shortened. The full README is on GitHub.