1. Register the agent and copy its token
In Monitor settings choose Register agent and name it after the machine. The rua_ token is shown once. Keep the tab open until the next step is done.
2. Run the installer
curl -fsSL https://realuptime.io/agent/install.sh | REALUPTIME_TOKEN=rua_your_token_here sh It uses Docker when the agent image can be pulled, and otherwise installs the release binary as a systemd service under your existing Node.js 22+. Either way the token goes into a root-only file, never onto a command line.
3. Verify what you ran, if you want to
The script downloads the release tarball and its SHA256SUMS and refuses to unpack on a mismatch. With cosign installed it also verifies the signature on SHA256SUMS against the public key at realuptime.io/.well-known/cosign.pub, the same key the Docker image is signed with.
4. Confirm it reports in
The agent appears as online in Monitor settings within a minute, and its server health page starts filling after the second sample. systemctl status realuptime-agent (or docker logs realuptime-agent) shows the agent's own JSON log lines if it does not.
5. If you run the container yourself, keep host networking
The installer's Docker path runs the image with --network host, and a Compose service needs network_mode: host. An agent watching its own host has to share that host's network: without it, 127.0.0.1 inside the container is the container, and every check pointed at a host-local service is refused forever while the service is healthy. An agent in that state says so on its own page in the dashboard and in its own log at startup.
Go deeper
The full reference lives in the docs: Monitor agent documentation. Error codes named above are each explained in the error-code reference.