The Co-op Anything project has released a method for programming agents to modify single-player games for multiplayer, currently applied to titles such as Deus Ex, Dungeon Keeper, S.T.A.L.K.E.R.: Shadow of Chernobyl, and Fallout: New Vegas. After the user specifies the target game, the agent analyzes the game structure, searches for existing mods, and either fixes old projects or builds network functionality from scratch depending on the situation.
If a game already has outdated, unmaintained, or unstable co-op mods, the agent will seek out the latest version, compile known issues, fix the code, and create a standalone software package. When no suitable mod exists, it is necessary to study the game engine, add a second player, and handle synchronization for enemies, world state, story, level transitions, and saves.
Current cases include fixing HX Co-op for Deus Ex, developing cooperative gameplay for Dungeon Keeper based on KeeperFX, and fixing Shadow of COOP for S.T.A.L.K.E.R.: Shadow of Chernobyl. The modification for Fallout: New Vegas involves synchronizing quests, dialogue, karma, and reputation.
The project also proposes using Steam Relay to simplify player connections, avoiding the need to manually open ports or use Hamachi, and supports automated testing on real game clients. The author emphasizes that this method is not a one-click conversion tool; the difficulty of modifying different games varies greatly. Closed-source titles may require full reverse engineering, and users still need to prepare the game themselves and allocate sufficient time for development and testing.