1. Install Node.js 22 or newer
From nodejs.org or Homebrew (brew install node). The agent has zero runtime dependencies of its own, so there is nothing else to install.
2. Run the installer
curl -fsSL https://realuptime.io/agent/install.sh | REALUPTIME_TOKEN=rua_your_token_here sh It installs the release binary as a launchd daemon that starts at boot and restarts on failure, and keeps the token in a file only the service can read. It reads vm_stat, df, netstat, ps and launchctl list with fixed arguments, and nothing else, to build its sample.
3. Watch services if you want to
On the agent's server health page, list the launchd labels you care about (com.apple.sshd, your own io.example.worker) under Watched services. Each reports active, inactive or failed on the next sample.
Go deeper
The full reference lives in the docs: Monitor agent documentation. Error codes named above are each explained in the error-code reference.