Import every site at once
In Netlify, create a personal access token under User settings, Applications. In the RealUptime dashboard, open Import, choose Netlify, and paste the token. The importer reads your sites once and shows a preview: each published site becomes one check on its custom domain, or on its netlify.app address when it has none. Sites that were never published are listed but not imported, since there is nothing live to check. The token is used for that one read and is not stored, so you can delete it in Netlify afterwards.
Or add a check by hand
export REALUPTIME_API_KEY=ru_live_...
realuptime checks create \
--name "Marketing site" \
--url https://www.example.com/ \
--interval 60See Checks & monitors for intervals, regions and assertions.
Add a status page
Create a status page from the dashboard and add the checks as components. See Status pages for custom domains and subscriber notifications.
What RealUptime does and does not see
A check sees the response your site returns, from each region you chose, like any other visitor. It does not see Netlify's build logs, deploy status or function logs; for those, Netlify's own dashboard is the source of truth. If part of your stack runs on a server you control, see Monitor Docker containers for that half.