check_endpoint — Judge one endpoint against the conditions a health dashboard uses: status it must return, a latency budget and text its body must contain.
health_rollup — Check up to 10 endpoints against the same conditions and report the pass rate and median latency across them.
endpoint_latency — Sample an endpoint several times and report fastest, median, average, slowest and how much the timings spread.
tls_expiry — Days left on a host's TLS certificate, who issued it and whether the chain is trusted.
dns_records — A, AAAA, NS, MX, TXT and CAA records for a domain, or just one type if you name it.
security_headers — Grade the response security headers a site sends: HSTS, CSP, frame options, content type options, referrer and permissions policy.
payload_report — How much a page actually transfers: bytes, compression, content type, cache headers, and what to fix for page weight.
allowed_methods — Which HTTP methods an endpoint answers: OPTIONS with its Allow header, plus whether HEAD and GET work.
health_path_probe — Probe the usual health endpoints (/health, /healthz, /status, /ready, /livez...) and report which one answers.

Setup

No setup. Every condition is evaluated live from the server itself, so there is no key or account.

Part of awesome-mcps.

Premium tools

These tools need a license key:

resolver_agreement
port_check

Buy a key at https://mcp-marketplace.io/server/io-github-mrfentmen-gatus-mcp and set it in your MCP client config:

"env": { "MCP_LICENSE_KEY": "mcp_live_..." }

The key is checked against MCP Marketplace, cached for 24 hours, and keeps working offline once one check has succeeded. Every other tool on this server stays free.