I loved Better Stack, and then the free plan kept getting thinner. What finally pushed me over: incidents used to get one Slack thread each, so an outage lived in one conversation instead of a stream of disconnected messages. That went away. I wanted it back, so I built my own.
The part I'd most like torn apart is the agents. You run one inside the network you want watched and it dials out over a WebSocket, so there's no inbound port and no firewall hole. On first start it generates its own keypairs and keeps the private halves — Ed25519 for identity, an X25519 (age) recipient that the server seals check credentials to. So the credentials for a private check are encrypted for that agent, and the server storing them can't read them.
All of it is open source: the agents, WhatsApp alerts, SSO, every check type. Nothing held back for a hosted edition.
Self-hosting is genuinely easy, and I depend on it, https://status.solidping.io is a second SolidPing running on fly.io that watches the cluster hosting the first one. A monitor that lives inside what it monitors isn't a monitor.
I've maintained a small Go FTP server library for 10 years (github.com/fclairamb/ftpserverlib), so open source isn't a marketing decision here.
Demo, no signup: https://solidping.io/demo Source: https://github.com/fclairamb/solidping
What I want is UX feedback and missing features — where the interface gets in your way, what you went looking for and couldn't find, what would have to exist before you'd run this instead of what you run now. Please be blunt. "Nice project" teaches me nothing.