For MusicBrainz mirrors, MusicBrainz server development, and custom applications, there used to be a direct access to search.musicbrainz.org which was actually inherited from the previous search infrastructure until 2018.
Keeping it available in the current infrastructure uses a compatibility layer which has been unintentionally broken last year. This issue has been reported only once. The alternative and much more sensible solution which is to install a local search server has improved in reliability and simplicity in the meantime. Polling the community shown that only one person would be interested which isn’t enough to justify the maintenance overhead for this replaceable service.
Therefore it has been decided to close this access for good.
Thanks to everyone who made this transitioning service to work and handle about 40k requests a day on average!
MetaBrainz Blog 