musiclibrary.dat
Requests
In Geometry Dash 2.2, the Music library has been added, adding thousands of songs that were not on Newgrounds to the game.
In 2.206, NCS was added to the music library, which forced RobTop to overhaul the file format.
The current library (as of 2.206) can be fetched via a GET request to https://geometrydashfiles.b-cdn.net/music/musiclibrary_02.dat.
The old music library can be fetched via a GET request to https://geometrydashfiles.b-cdn.net/music/musiclibrary.dat.
You can also fetch the latest version of the Music Library by sending a GET request to https://geometrydashfiles.b-cdn.net/music/musiclibrary_version_02.txt (for the old library, the link is https://geometrydashfiles.b-cdn.net/music/musiclibrary_version.txt. As of the writing, the latest version for the old library is 114 and this is unlikely to change in the future).
The Music library format is covered here.
Downloading Songs
You can download a track by sending a GET request to https://geometrydashfiles.b-cdn.net/music/{id}.mp3. All Music Library song IDs have an offset of 10,000,000 to not interfere with the Newgrounds songs.
CDN Tokens
The GD client currently sends two parameters for every https://geometrydashfiles.b-cdn.net request: token and expires. While these aren't required as of the time of writing, they may be required in the future. Click here to find instructions how to generate the CDN tokens.
Archive
The music library and SFX library versions are auto-archived by Cvolton at https://cvolton.eu/sfx.