This [Authserver](https://github.com/vierbergenlars/authserver) plugin that requires users to accept some terms of service before they can use their account.
Set `tos.version` to the version of your terms of service. This number should be increased every time the terms of service change, so users get prompted to accept the new terms. The version of the latest accepted version is stored per user. If the stored number is lower than the configured version, the user is prompted.