API, port, and ping monitors
Add HTTP endpoint and TCP port checks, and manage the ICMP ping monitoring tested automatically when a site is created.
Beyond the checks that run automatically once you add a site, a site's Monitors tab lets you add API and port monitors and manage ICMP ping monitoring for things a plain uptime check can't see. For scheduled jobs and recurring background work, see cron job monitoring.
API monitors
Check a specific HTTP endpoint on a schedule, separate from the site's main uptime check — useful for a health endpoint, an authenticated API route, or a webhook receiver.
- Open a site's Monitors tab and click Add API monitor.
- Set the method (GET, POST, etc.), the URL, and optional headers/body.
- Set expected status codes — the check fails if the response doesn't match.
- Choose a check interval.
Failures show up on the dashboard and can trigger an API monitor failing alert rule.
Port monitors
Check that a TCP port is open (or closed, if that's what you expect) — useful for database ports, SSH, or any non-HTTP service.
- From the Monitors tab, click Add port monitor.
- Set a label, the host, and the port number.
- Choose the expected state — open or closed.
- Choose a check interval.
Ping monitoring
A lighter-weight ICMP ping check, as an addition to the main HTTP uptime check. When you add a site, DownCTL runs an initial ICMP check: if the host responds, ping monitoring stays on; if the host is confirmed unreachable, DownCTL turns it off because many CDNs, load balancers, and firewalls block ICMP even when the website is healthy.
An execution problem on DownCTL's side is recorded as Unknown and does not turn ping monitoring off. Once enabled, ping runs on the same check interval as the site's uptime check. You can turn it on or off at any time from the site's Monitors tab; later failed checks report the failure but do not change that setting.
Vendor dependency monitors
Watch a third-party vendor's own status page — useful when a client site depends on a payment processor, CDN, or hosting provider that could break things outside your control. See third-party and vendor status monitoring for details.