🧩 What is SSMP Enemy Syncing Addon?

SSMP Enemy Syncing Addon is an expansion mod for Hollow Knight: Silksong Multiplayer (SSMP). It enables complete, real-time multiplayer synchronization for all standard enemies, mini-bosses, and complex multi-phase bosses throughout Pharloom.

In addition to enemy synchronization, it introduces a Co-op Downed & Cocoon Revive System, allowing teammates to rescue each other in battle!

[!WARNING]

⚠️ Work in Progress & Development Disclaimer

This mod is still actively in development and is not perfect. You may encounter desyncs, glitches, or game-breaking bugs during multiplayer sessions.

Please back up your save files, report bugs on the GitHub Issues page, and share your feedback!

✨ What's New in v1.0.1

• 🔌 Native BepInEx Plugin Integration: Added EnemySyncingPlugin entry point (bg52.enemysync.ssmp) allowing the mod to be loaded directly by BepInEx and managed via Thunderstore / r2modman seamlessly.
• 🎯 Boss Aggro & Target HUD Indicators: When a boss targets a player in combat, that player's nametag dynamically turns red, giving immediate tactical feedback to teammates.
• 💀 Corpse Snapshot & Death Sync: Enemy deaths now synchronize exact knockback velocity, position, rotation, and attack angles across all clients.
• 🛡️ Scene Owner Death Verification: Implemented authoritative death validation (VerifyEnemyDieRequest) to prevent client-side desync and duplicate phantom enemies.
• 🏹 Enhanced Projectile Synchronization: Added support for projectile animation clip states, custom scaling (ScaleX), and improved trajectory tracking.
• 🧠 PlayMaker FSM Target Patches: Overhauled FSM distance/position calculations (GetDistance, GetXDistance, GetYDistance, GetPosition) so enemies consistently navigate toward their active network target.
• 🔄 Anti-Duplication & Desync Recovery: Background watchdog monitors and restores missing scene enemies while cleaning up stale or dead entities.

⚡ Core Features

⚔️ Complete Network Synchronization

👑 Dynamic Authority & Claiming System

• Proximity & FOV Claiming: The nearest player looking at an enemy automatically claims authority to control its AI and movement.
• Boss Target Highlighting: Players currently targeted by active bosses are highlighted with a red username tag.
• Host Fallback: Unclaimed or distant enemies cleanly fall back to host-side simulation to eliminate desync.
• Auto-Spawner for Missing Enemies: Automatically instantiates missing scene prefabs for late-joining players.

🕸️ Downed & Cocoon Revive System

• Multiplayer Downed State: Upon taking fatal damage, players enter a protective Cocoon state instead of instantly dying.
• Teammate Revives: Nearby teammates can strike a fallen player's cocoon with their weapon to break them free and revive them back into action.
• Hazard Auto-Settling: Cocoons falling into spikes or environmental hazards automatically settle onto the nearest safe ground.
• Hold-to-Suicide Action: Stuck or isolated players can hold their Quick Map key (default: TAB / Controller equivalent) to surrender and respawn.
• Team-Wipe Logic: If all players in the active scene are cocooned simultaneously, the mod triggers a synchronized native team defeat.

🎮 How It Works

1. Take Fatal Damage  →  Player enters Cocoon State (Invulnerable to hazards)
2. Teammate Hits      →  Striking the cocoon reduces HP & breaks player free!
3. Team Wipe Check    →  If everyone is downed → Sync'd team defeat & respawn

📥 Installation Guide

Via Thunderstore / r2modman (Recommended)

1. Install SSMP Enemy Syncing Addon directly through the Thunderstore Mod Manager or r2modman.
2. Launch the game via the mod manager.

Manual Installation

1. Prerequisites:
   • Hollow Knight: Silksong
   • BepInExPack for Silksong
   • SSMP (Silksong Multiplayer)
2. Install Addon:
   • Extract EnemySyncing.dll into your BepInEx plugins directory: path\to\Hollow Knight Silksong\BepInEx\plugins\EnemySyncing\ (or inside BepInEx\plugins\SSMP\).
3. Run the Game:
   • Launch Silksong. BepInEx and SSMP will automatically load EnemySyncing.dll.
   • Note: Both Host and joining clients must have EnemySyncing installed.

⚙️ Keybinds & Controls

🛠️ Building from Source

Requirements

• .NET 8.0 SDK or later
• Visual Studio 2022 / JetBrains Rider / VS Code

Steps

# 1. Clone the repository
git clone https://github.com/Brothergaming52/EnemySyncing.git
cd EnemySyncing

# 2. Build the solution
dotnet build EnemySyncing.csproj -c Release

The compiled binary will be placed in bin/Release/netstandard2.1/EnemySyncing.dll.

🙌 Credits & Acknowledgements

• Brothergaming52 – Creator & Lead Developer
• FieryCGamingz – Addon Tester & Quality Assurance

☕ Support the Project

📜 License

This project is licensed under the MIT License.

Changelog

All notable changes to the SSMP Enemy Syncing Addon will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[1.0.1] - 2026-08-18

Added

• Native BepInEx Plugin Loader (EnemySyncingPlugin):
  • Registered as bg52.enemysync.ssmp with dependency on ssmp.
  • Enables automatic addon discovery and seamless 1-click installation via Thunderstore / r2modman into BepInEx/plugins/.
• Boss Target HUD Indicators:
  • Dynamically changes the active boss's target player nametag to Red across UI Text, 3D TextMesh, and TextMeshPro components.
  • Reverts back to original color when the boss switches targets or dies.
• Corpse Snapshot & Death Synchronization:
  • Added corpse position, rotation, and knockback velocity synchronization on enemy defeat.
• Scene Owner Death Verification:
  • Added VerifyEnemyDieRequest and SceneOwnerNotify packets to prevent phantom duplicate spawns and desyncs.
• Enhanced Projectile Synchronization:
  • Added projectile animation clip and ScaleX scale synchronization across network.
• Anti-Duplication Watchdog:
  • Background entity monitor to restore disabled alive entities and clean up dead entities across scenes.

Changed

• Overhauled PlayMaker FSM distance and position overrides (GetDistance, GetXDistance, GetYDistance, GetPosition) for precise target tracking.
• Improved Downed Cocoon mechanics, suicide keybind prompt UI, and team wipe resolution.

Fixed

• Fixed desync where enemies would fail to register deaths from non-host clients.
• Fixed boss targeting becoming stuck after player death or scene transitions.

[1.0.0] - 2026-07-26

Added

• Initial Release of SSMP Enemy Syncing Addon:
  • Real-time position, rotation, and animation state synchronization for enemies and mini-bosses.
  • Multi-phase boss state synchronization and PlayMaker FSM action mirroring.
  • Proximity and FOV dynamic enemy authority claiming system.
  • Host fallback simulation for unclaimed or out-of-range enemies.
  • Co-op Downed Cocoon & Teammate Revive mechanics.
  • Quick Map hold-to-give-up suicide action for trapped cocooned players.
  • Team wipe check and coordinated respawns.