subnautica-2-coop-mod-bepinex

What problem does it solve?

It solves the challenge of playing Subnautica 2 cooperatively by enabling synchronized multiplayer gameplay across multiple players, including shared world state, inventory, and base-building actions.

Core Features & Use Cases

• Deterministic session synchronization (DSS) to keep shared world state consistent and reduce conflicts between peers.
• Shared inventory with integrity verification using Merkle tree hashing to detect and reconcile desync.
• Co-op base building synchronization so structures placed by one player appear for others in real time.
• Host migration and session recovery to preserve progress and minimize disruption if the host disconnects.
• Cross-platform networking transport using WebRTC/NAT punch-through for wider joinability.

Use case examples:

• Organizing friends to explore, build bases, and manage resources together without item/world mismatch.
• Running a co-op session where one player hosts, then safely continuing if the host drops.
• Coordinating large collaborative builds where every placed component must match across clients.

Quick Start

Install BepInEx for Subnautica 2, copy the DeepSynergy plugin DLLs into the BepInEx/plugins directory, and configure BepInEx/config/synergy_profile.json before starting or joining a co-op session.