Beat Saber for the Quest has no included ability to play custom songs or visual/functional modifications that the PC version can do.
BMBF is a tool you install on the Quest (usually via SideQuest) that actually makes binary modifications to Beat Saber and allows for custom songs and mods (outside the scope — read this article for more info on mods) to be installed.
The nerve center for “modified Beat Saber”, BMBF doesn’t need to be actively running for Beat Saber to use custom songs; we only need to run it when we want to add/remove/update songs and mods — as well as perform maintenance.
Outside of patching Beat Saber, when running, BMBF is a web server app that allows you to perform functions within the headset or from any computer on the same network. This allows us access to BMBF from any computer on your network (as long as BMBF is running on the Quest).
BMBF performs the following functions:
- Patching Beat Saber to allow for custom songs and mods
- Accept the uploading of songs and mods
- Playlist creation and organization
- SyncSaber: Syncing songs from Beast Saber (bookmarks and other lists). See our article on Bookmark Syncing.
- Perform maintenance on BMBF-related resources, uninstall modified Beat Saber, etc.
- Exposes APIs for tools like my Beat Mapper Tools and Playlist Editor Pro to perform song and playlist updates