Sign In

Everybody can sign in except when they can’t
Slack Apps requesting only the identity family of scopes do not contribute to the maximum number of integrations that free teams may install.

Team administrators may configure whether Sign in with Slack is available to their team members, separately from any application installation restrictions already in place.

Guest accounts can not use Sign in with Slack.

Sign in again and again
Sign in with Slack is optimized for logging in. Returning users won’t be distracted by unnecessary approvals, we’ll send them back to your site, service, or app as fast as we can!

via Sign in with Slack | Slack