Decoupled (Perfect LAN)

Decoupled is an advanced Fabric optimization mod that completely separates the integrated server from the client's Java process in singleplayer.

By spinning up the singleplayer world as a true Dedicated Server running in the background, Decoupled completely isolates the client from server-side lag spikes, chunk generation stutter, and Garbage Collection (GC) pauses. It delivers flawlessly smooth 1% low FPS, making singleplayer feel as smooth as playing on a premium multiplayer server.

Features

• True Multi-Processing: Splits Minecraft into two separate Java Virtual Machines (JVMs).
• Flawless 1% Lows: World generation, mob AI, and redstone calculations no longer block the client's Render thread.
• Perfect LAN: Opens your world to the local network automatically without Windows Firewall issues. The server port is printed directly to the host's chat.
• In-Game Configuration: Configure background server RAM and CPU cores allocation directly from the client's mod menu.
• Smart Pause (TickRateManager): Vanilla's ESC pause still works flawlessly! It seamlessly freezes the background server entities and world time without interrupting the network KeepAlive packets.
• Host Persistence: Uses a custom login handshake interceptor (HostIdentityMixin) to ensure the host keeps their original Singleplayer inventory and stats, regardless of nickname or offline mode status.

Requirements

• Memory: Minimum of 12-16 GB of system RAM. Running two JVMs simultaneously increases the base memory footprint.
• CPU: 6-core processor or better recommended for optimal OS-level context switching between processes.

Recommended Mods (Synergy)

For the ultimate performance, we highly recommend using this mod alongside:

• C2ME (Concurrent Chunk Management Engine): Since Decoupled isolates the server into its own process, C2ME allows that background server to generate chunks using extreme multi-threading without ever stuttering your client. The difference in chunk loading speed is colossal!
• Lithium: Further optimizes the background server's tick rate and AI.
• Sodium: Keeps your client-side rendering buttery smooth while Decoupled handles the server logic.
• EasyAuth / FastLogin: If you want to play with both Premium and Cracked friends simultaneously, just drop one of these mods into your folder. Since Decoupled runs a real dedicated server, these mods will perfectly restore skins and Mojang UUIDs for your premium friends while still letting offline players join!

Known Limitations

• Mod configs altered via Mod Menu on the client do not sync to the background server in real-time. You must restart the world to apply server-side config changes.
• Requires raw system resources. Not recommended for old dual-core laptops with 8 GB of RAM.

How to Play with Friends

Simply join your singleplayer world. The mod will automatically print the assigned background server port in your chat. Share your IP address (Local/Hamachi/Radmin) and that port with your friends!

License

MIT