Midnight1 aims to add more advanced membership management features to Matrix homeservers like Synapse.
It is written in the Swift programming language and the Vapor framework for a nice balance of performance, concurrency, and built-in memory safety.
Midnight adds support for token-based signup in the Matrix user-interactive authentication API (aka the UIAA).
This support is superficially similar to the token-based registration that the matrix-registration project offers. However, where matrix-registration uses its own custom API, Midnight complies with the official Matrix UIAA specification. Thus it should be more straightforward for Matrix clients to add support for Midnight's token-based registration.
Midnight can filter out undesirable usernames before allowing users to register.
It can be configured to reject usernames that contain "bad" substrings such as curse words or racial slurs. For example, adding "poop" to the list of bad substrings would reject all usernames like "poophead" or "MrPoopyPants".
It can also be used to disallow the use of usernames from a set of reserved usernames. For example, a homeserver might want to block anyone from registering with the username "root" due to its association with the Unix administrator account. This would still allow usernames like "Groot" or "TreeRoots" to be used, as long as they don't match a reserved name exactly.
By default, Midnight also enforces a set of readability constraints on usernames, more strict than the official Matrix specification. It rejects usernames that start or end with punctuation, as these could be used to impersonate other accounts, e.g. registering as "bob." or "bob_" to impersonate the real account "bob".
In the near future, we plan to add integration with Apple's App Store subscriptions. This would allow any user with a valid subscription to register for a Matrix account on the homeserver.
Other subscription services, such as the Google Play Store, are also of interest.
Midnight sits "in front of" a standard Matrix homeserver like Synapse
or Conduit.
It handles just a few of the Matrix client-server API endpoints.
(At the moment, it's actually just one endpoint: register.)
If you're using a reverse proxy like nginx, you should forward most of the Matrix
API endpoints directly to your "real" homeserver like Synapse. Forward the
registration-specific endpoints, like /_matrix/client/(r0|v1)/register, to Midnight.
Maybe you're running a small homeserver for your friends and family. You don't want to open up registration to the whole world, but you also don't want to deal with emailing everyone an initial password and hoping that they change it. (Protip: They won't.)
Or, alternatively, maybe you're running a subscription service, like us. Midnight was developed for use with the upcoming Circles project.
1 Yes, the name is a silly reference to an old Steve Miller Band song.