Documentation

Real ICMP echo to confirm a host is reachable at the network layer — independent of any service running on it.

Fetch a URL on a schedule and assert that the response code is in your expected set. The default and most useful check for any web service.

Opens a TLS connection to your host on port 443, reads the leaf certificate, and warns before expiry. Catches forgotten renewals before they take production down.

Looks up a DNS record on a schedule, optionally asserting the response matches an expected value. Detects misconfigurations, propagation lag, and registrar issues.

Opens a TCP connection to a host:port. Supports two modes — fail if the port is closed (standard) or fail if the port is open (security hygiene).

Queries WHOIS for the registration expiry date of your domain and alerts when renewal is due. Different from SSL — this is about the registrar, not the certificate.

Checks whether your host's IP appears on common email blacklists. Critical for any service that sends transactional or marketing email.

Inverse of every other monitor. Your job pings us on schedule; we open an incident when we don't hear from it within the grace window.

Where downtime alerts go. Configure one or more channels (email, Slack, Discord, Telegram, webhook) and route specific monitors to specific channels.

A public, no-auth URL that shows the live state of a chosen set of monitors. Hand it to customers as proof you know about incidents before they have to ask.

Bearer tokens that authenticate programmatic callers against /api/v1/*. Scoped, revocable, and shown to you exactly once at creation time.

Rules that decide when a notification fires. Default: any DOWN check fires immediately. Tune the threshold to absorb single-check flakiness.