RunStack Checks MCP server

RunStack MCP — external infrastructure checks for AI agents

Remote MCP server that checks your public infrastructure from the outside — the way users, browsers and other mail servers see it — and returns a diagnosis: verdict, findings with cause and fix, and a shareable report link.

Nothing runs locally and nothing runs on your servers: only public data is checked.

• Endpoint: https://runstack.pro/api/mcp (Streamable HTTP, stateless)
• Auth: header X-RunStack-Key: rsk_... (or Authorization: Bearer rsk_...)
• Free key: https://runstack.pro/account — 200 calls/day
• Registry name: pro.runstack/checks

Tools

Tool	What it checks
check_tls	Certificate validity and chain, expiry, hostname, TLS 1.0–1.3, ciphers, HSTS
check_http	Status, redirect chain, security headers (HSTS, CSP, X-Frame-Options…), caching, compression
check_email_domain	MX, SPF (10-lookup limit), DKIM, DMARC, PTR/FCrDNS, STARTTLS, MTA-STS, TLS-RPT, BIMI
check_dns	Answers from several public resolvers compared — propagation, NXDOMAIN, inconsistencies
check_port	TCP ports open / closed / filtered from the internet
check_ip	IP or ASN owner, prefix, PTR, RPKI, geolocation

All tools are read-only.

Example (abridged, real output)

"Check the mail setup of runstack.ru"

FAIL: Mail domain runstack.ru: critical issues
- MX: 10 mxs1.reg.ru, 20 mxs2.reg.ru
- SPF: ~all · lookups 4/10
- DMARC: p=none
- DKIM: dkim

Findings:
- [error] Multiple DMARC records
  why: _dmarc.runstack.ru has 2 v=DMARC1 records — receivers then ignore DMARC entirely. Keep one.
  how-to: https://runstack.ru/docs/fix-dmarc-p-none
- [info] SPF ~all (softfail)
  why: Soft fail — common during monitoring.
- [info] MX certificate not valid for the server name
  why: STARTTLS works, but the MX certificate doesn't match the name. Matters for MTA-STS and DANE.

Yes, that is our own domain — the check found it.

Setup

Claude Code

claude mcp add --transport http runstack https://runstack.pro/api/mcp --header "X-RunStack-Key: rsk_..."

Cursor (~/.cursor/mcp.json) / VS Code / other clients

{
  "mcpServers": {
    "runstack": {
      "url": "https://runstack.pro/api/mcp",
      "headers": { "X-RunStack-Key": "rsk_..." }
    }
  }
}

Codex (~/.codex/config.toml)

[mcp_servers.runstack]
url = "https://runstack.pro/api/mcp"
http_headers = { "X-RunStack-Key" = "rsk_..." }

Language

Diagnoses are in English on runstack.pro. Russian: https://runstack.ru/api/mcp or ?lang=ru.

Links

• Website: https://runstack.pro
• REST API: https://runstack.pro/developers
• Telegram bot: https://t.me/RunStackru_bot