Co-op multiplayer for X4: Foundations — up to 4 players
Build 15 • 154 KB • Windows only
Right-click x4mp-build15.zip and choose Extract All. You will get a folder called x4mp.
Press Win + R, paste this and hit Enter:
%USERPROFILE%\Documents\Egosoft\X4
Open the folder with your Steam ID (a long number), then open extensions. If extensions doesn’t exist, create it.
Move the x4mp folder you extracted into extensions. The result should be:
...\extensions\x4mp\content.xml
Launch X4 → press Esc → Settings → General → find Protected UI Mode and set it to Off. Restart the game.
Once in-game (in your save), press M to open the X4MP lobby menu.
To host: select Host, enter your name and a port (default 7842), then click Start. Tell your friends your IP address and the port.
To join: select Join, enter your name, the host’s IP address, and the port, then click Start.
Protected UI Mode must be OFF or the mod will silently fail to load and the M key will do nothing. If it’s not working, go back to Step 4 and double-check.