RunStack Checks MCP Server

by runstack Your server? Claim it

answering

RunStack Checks is answering right now. Last checked 12 min ago. It exposes 8 tools. Last commit 18 Oct 2026.

External checks of TLS, HTTP headers, email domain, DNS and ports, with cause and fix

Uptime history 9 days of history

9 days agonow

100.0%

Uptime 24h

91 of 91 checks

Tools

read from the server

110 ms

Response time

average over 24h

Stars

last commit 18 Oct 2026

What changed 14

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 18 October 2026. No other catalogue keeps this.

19 Oct 2 tools appeared check_dnsbl, check_domain_expiry

18 Oct 5 tool descriptions were rewritten check_dns, check_email_domain, check_http and 2 more

18 Oct 5 tools changed the parameters they ask for check_dns, check_email_domain, check_http and 2 more

18 Oct a tool appeared check_ip

18 Oct a tool disappeared ip_lookup

Tools have disappeared from this server

A tool that vanishes takes a piece of your agent with it, and the change arrives silently. Watch this server and every such change lands in your inbox.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 12 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add checks --transport http https://runstack.pro/api/mcp

Settings → Connectors → Add custom connector, then paste this address

https://runstack.pro/api/mcp

~/.codex/config.toml

[mcp_servers.checks]
url = "https://runstack.pro/api/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "checks": {
      "url": "https://runstack.pro/api/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "checks": {
      "type": "http",
      "url": "https://runstack.pro/api/mcp"
    }
  }
}

Available tools 8

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

check

check_ip

Look up an IP address or ASN: owner organization, announced prefix, PTR (reverse DNS), RPKI validity and geolocation. Use to identify who is behind an address seen in logs or headers, or to check PTR / RPKI for a mail or BGP issue. Does not test reachability (use check_port).

dns

check_dns

Resolve a name at several public resolvers (Google, Cloudflare, Quad9, …) and compare their answers. Use after changing DNS records to check propagation, or when some users reach a different IP or get NXDOMAIN. Use check_email_domain instead for SPF/DKIM/DMARC analysis. Returns per-resolver answers, inconsistencies and a verdict.

dnsbl

check_dnsbl

Check whether an IP address or a domain is on email blocklists (DNSBL/RBL): Spamhaus ZEN and DBL, SpamCop, Barracuda, UCEPROTECT, Mailspike, SURBL, URIBL and others. For a domain, its own name is checked on domain lists and its A/AAAA addresses on IP lists. Use when mail bounces with 'listed'/'blocked' errors or lands in spam, or after a server was compromised. Lists that refuse queries from public resolvers are reported as not tested, never as listed. Returns listed lists with the reason and a delisting link. For SPF/DKIM/DMARC use check_email_domain.

domain

check_domain_expiry

Look up a domain's registration in the registry (RDAP, or WHOIS for .ru/.su/.рф): expiry date and days left, registrar, creation date, EPP status codes (clientHold, redemptionPeriod, transfer locks…) with explanations, nameservers and DNSSEC. Use to check when a domain must be renewed or why it suddenly stopped resolving. Subdomains are reduced to the registered domain. For DNS records use check_dns.

check_email_domain

Audit a mail domain as other mail servers see it: MX, SPF (including the 10-DNS-lookup limit), DKIM, DMARC policy, PTR / forward-confirmed reverse DNS, SMTP STARTTLS on the MX hosts, MTA-STS, TLS-RPT, BIMI. Use when mail lands in spam or bounces, after changing mail provider or DNS, or before tightening DMARC. Use this (not check_dns) for any email deliverability or authentication question. Returns a verdict, findings with cause and fix, and a report link.

http

check_http

Request a public URL from outside your network and inspect the HTTP layer: status code, full redirect chain, security headers (HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy…), caching and compression headers. Use to debug redirect loops, unexpected status codes or missing headers as real visitors and CDNs see them, or to verify a web server / CDN config change after deploy. Use check_tls instead for certificate or TLS protocol questions. Returns a verdict and findings with fixes.

port

check_port

Check from the internet whether TCP ports of a public host are open, closed or filtered. Use to verify firewall / security group rules, or to find out why a service works locally but is unreachable from outside. Only public addresses are accepted; this does not test the application behind the port (use check_http or check_tls for that).

tls

check_tls

Scan a public host's TLS from the internet: certificate validity, chain completeness, expiry date, hostname match, enabled protocols (TLS 1.0–1.3), cipher suites, HSTS. Use when browsers show certificate errors, before/after renewing or rotating a certificate, or to confirm old TLS versions are disabled. Use this (not check_http) for anything about the certificate or TLS configuration itself; works on any TLS port, not only 443. Returns a verdict, findings with cause and fix, and a shareable report link. Takes up to ~60 s.

Tools removed

Tools this server used to expose. Anything built against them stopped working on the day they went.

ip_lookup

removed 18 Oct 2026

Endpoints

URL	Transport	State	Latency	Checked
https://runstack.pro/api/mcp	streamable-http	answering	67 ms	12 min ago

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RunStack Checks — questions

Answers built from our own checks of this server.

What can RunStack Checks do?

It exposes 8 tools, read directly from the server on our last check. Among them: check_dns, check_dnsbl, check_domain_expiry, check_email_domain, check_http, check_ip and 2 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →

Is RunStack Checks working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 110 ms. The bar chart above shows every period we have measured.

Did RunStack Checks ever remove tools?

Yes. ip_lookup is no longer exposed — we recorded the date each one disappeared. A tool vanishing usually means a breaking change for anything that depended on it.

How do I connect RunStack Checks?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does RunStack Checks need an API key?

No. RunStack Checks completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 8 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is RunStack Checks?

It answers our handshake in 110 ms on average, which is faster than 95% of all working MCP servers we measure. That puts it in the quick quarter of the ecosystem. The comparison comes from our own checks across the whole registry, every 15 minutes.

Is RunStack Checks open source?

We cannot say either way: 0 stars on GitHub and 1 open issue, but we could not determine the licence, and without one the code is not open source by default.