Client Building

Build your own client.jar

Ask for an invite to https://github.com/GregHib/void-client

Modify an existing 634 deob

To make another 634 compatible you'll neeed to:

1. update the RSA keys
2. Use debug ports 50015 by setting "modewhere" property to "1"
3. Split the game and file-server ports by adding false to loginType == 2 in the first login stage
4. Disable the lobby by setting the initial login stage to 2
5. Fix the area sound packet from (id = 5, size = 6) to size = 8
6. Support java 6+

Code changes can be found here however naming will likely differ in your deob client.