Active, away and automatic
Slack shows two presence values: active and away. By default it is automatic: Slack decides from your activity. You can override it by setting yourself as away, and switching back returns it to automatic.
What counts as activity
Slack’s servers detect activity from your client. After about ten minutes without any, you are marked away. Mobile works differently: leaving the app sets you to away.
What apps can’t do
Slack’s API lets apps set presence only to automatic or away. There is no supported way for an app to force “active”. That’s why a service that keeps you green has to hold a real client connection rather than flip a switch.
Who can see what
Everyone in the workspace sees your active or away indicator. Workspace owners and admins can also open member analytics by default; the exact data depends on your plan and your workspace’s settings.
Status text vs presence
Your custom status (an emoji and a short text such as “On vacation”) is separate from presence. Stayslit can read only your status emoji so it can pause itself in vacation mode.