So, I've been writing a mod which requires the username of each player that uses the mod. I'm currently using Minecraft.getMinecraft().thePlayer.getGameProfile().getName(). However, this method only works if the player has loaded into a World, and I need the player username when the game launches. I know that this information is stored somewhere, because the game prints it out as a debug statement. Anyone have any insight?

Have you looked into the Session class? I believe the players username is set to a value stored in the session class, and the session class is created in the main() method.

Thank you very much! I knew about sessions, but I seem to have forgotten that it stores the username in plaintext.