client key login

Client Key Login stores an identity on the player's machine that the mod uses to sign in to a server, so a player can authenticate servers with cryptography rather than relying on a Mojang account. Players can create several identities, switch between them quickly, and keep using protocol encryption while playing offline. Because the identity is separate from the account, it can carry a customised profile and clone the skin and cape textures of an existing Mojang account.

The mod is installed on Fabric and needs Fabric API. Client and server must both run it, and the code is released under The Unlicense, so it is open source. Files cover 1.19.2 – 1.21.1 across seven release versions, with 0.4.3+1.21 for 1.21.1 as the latest Fabric file, published on the beta channel. Vanilla servers accept a client with the mod installed, while proxies such as BungeeCord, Velocity and Waterfall do not understand the custom protocol, so a player who uses one of them has to join with a regular Mojang account and change back to the same identity.