They sign in with the address you enter (we email a code). Invites expire; revoking one cuts access at once.

When a change to a build’s code is merged on GitHub it lands here (checked every hour, or press the button). Publish it, editing the line first if you like, and visitors see it under “What’s new” on that build. Dismiss the ones that aren’t worth showing. A build set to publish automatically skips this step.

Every time an invited person opens a build or clicks through to the live site. Staff looking is not counted.